'''Subroutines'''
'''***********'''
DECLARE SUB melo ()
DECLARE SUB funcupara ()
DECLARE SUB coorcupara ()
DECLARE SUB figuurtit ()
DECLARE SUB prefsmore ()
DECLARE SUB prefscol ()
DECLARE SUB funcirkel ()
DECLARE SUB funcosin ()
DECLARE SUB fundubhyp ()
DECLARE SUB funcosec ()
DECLARE SUB funexpon ()
DECLARE SUB funparab ()
DECLARE SUB funsino ()
DECLARE SUB funsinq ()
DECLARE SUB funtangens ()
DECLARE SUB afbmod3 ()
DECLARE SUB rotstap ()
DECLARE SUB schermkleur ()
DECLARE SUB scanmax ()
DECLARE SUB scanmod ()
DECLARE SUB tekenen ()
DECLARE SUB figpref ()
DECLARE SUB prefs ()
DECLARE SUB tekenxyas ()
DECLARE SUB tekenparm ()
DECLARE SUB tekencurv ()
DECLARE SUB tekenxyvlak ()
DECLARE SUB intro ()
DECLARE SUB tekenxy ()
DECLARE SUB figcurv ()
DECLARE SUB menu ()
DECLARE SUB rotkeus2 ()
DECLARE SUB projas2 ()
DECLARE SUB afbmod2 ()
DECLARE SUB figuur2 ()
DECLARE SUB scherm ()
DECLARE SUB figuur ()
DECLARE SUB tekencoord ()
DECLARE SUB tekenfig ()
DECLARE SUB rotkeus ()
DECLARE SUB coorcirkel ()
DECLARE SUB coordubhyp ()
DECLARE SUB coorcosec ()
DECLARE SUB coorexpon ()
DECLARE SUB coorparab ()
DECLARE SUB coorcosin ()
DECLARE SUB coorsino ()
DECLARE SUB coorsinq ()
DECLARE SUB coortan ()
DECLARE SUB afbmod ()
DECLARE SUB projas ()
DECLARE SUB cirkel ()
DECLARE SUB dubhyp ()
DECLARE SUB cosec ()
DECLARE SUB expon ()
DECLARE SUB parab ()
DECLARE SUB cosin ()
DECLARE SUB tangens ()
DECLARE SUB sino ()
DECLARE SUB sinq ()
DECLARE SUB rot1 ()
DECLARE SUB rot2 ()
DECLARE SUB rot3 ()
DECLARE SUB rot4 ()
DECLARE SUB rot5 ()
DECLARE SUB rot6 ()
DECLARE SUB rot7 ()
DECLARE SUB rot8 ()
DECLARE SUB rot9 ()
DECLARE SUB rot10 ()
DECLARE SUB rot11 ()
DECLARE SUB rot12 ()
DECLARE SUB rot13 ()
DECLARE SUB teken ()
DECLARE SUB teken2 ()

'''Variabelen'''
'''**********'''
COMMON SHARED a, b, alf, bet, cca, ccb, ssa, ssb, tta, ttb, alfr, betr
COMMON SHARED pi, nrot, drot, tel, xi, nr%, scan, scr
COMMON SHARED u1, u2, u3, u4, v1, v2, v3, v4
COMMON SHARED u11, u22, u33, u44, v11, v22, v33, v44
COMMON SHARED men, fig, max, xy, fac, yx, nmax, mmax, delthoek, deltx2
COMMON SHARED tit$, c$, rot$, xy$, parm$, ja$, curv$
COMMON SHARED f$(), fmen$(), ffig$(), frot$(), scr$(), mel$()
COMMON SHARED afb$(), afb1$(), afb2$(), afb3$(), col(), scol(), scrcol()'''col1(), col2()
COMMON SHARED x1(), x2(), y1(), y2(), u(), v()
COMMON SHARED r(), rdub(), xx1sec(), xx2sec(), xx1exp()
COMMON SHARED rpar(), rcupar(), xxsin1(), xxsin2(), xxtan1(), xxtan2()
COMMON SHARED colm, coln, colmm, colnn, colx, coly, colxx, colyy, mel
COMMON SHARED colcrv1, colcrv2, colcrv3
COMMON SHARED rij, kol, vlag, vlagxy

'''Titels'''
'''******'''
DIM fmen$(6)
fmen$(0) = " -> AFBEELDEN"
fmen$(1) = " -> figuur"
fmen$(2) = " -> rotatie"
fmen$(3) = " -> projectieassen"
fmen$(4) = " -> voorkeurinstellingen"
fmen$(5) = " -> Omtrent COMPLEXITY..."
fmen$(6) = " -> END"
DIM ffig$(10)
ffig$(0) = "-> X en Y -eenheidsassen"
ffig$(1) = "-> Cirkel/Hyperbool : Y=1/X"
ffig$(2) = "-> Dubbelhyperbool. : Y=1/X^2"
ffig$(3) = "-> Cosecans........ : Y=1/Sin(X)"
ffig$(4) = "-> Exponentieel.... : Y=e^X"
ffig$(5) = "-> Parabool........ : Y=X^2"
ffig$(6) = "-> Cosinus......... : Y=Cos(X)"
ffig$(7) = "-> Tangens......... : Y=Sin(X)/Cos(X)"
ffig$(8) = "-> Sinuoid......... : Y=Sin(2pi X)"
ffig$(9) = "-> Quadsin......... : Y=Sin^2 (X)"
ffig$(10) = "-> Cubische parab.. : Y=X^3"
DIM frot$(13)
frot$(1) = " 1 = x1-as alleen"
frot$(2) = " 2 = y1-as alleen"
frot$(3) = " 3 = x2-as alleen"
frot$(4) = " 4 = y2-as alleen"
frot$(5) = " 5 = x1-x2 vlak (X-vlak)"
frot$(6) = " 6 = y1-y2 vlak (Y-vlak)"
frot$(7) = " 7 = x1-y1 vlak (reeel vlak)"
frot$(8) = " 8 = x2-y2 vlak (imag. vlak)"
frot$(9) = " 9 = x1-y2 vlak"
frot$(10) = "10 = x2-y1 vlak"
frot$(11) = "11 = X-vlak + Y-vlak"
frot$(12) = "12 = x1-y1 + x2-y2 vlakken"
frot$(13) = "13 = x1-y2 + x2-y1 vlakken"
DIM afb$(7), afb1$(7), afb2$(7)
afb$(1) = "-> Beeld opbouwen"
afb$(2) = "-> Parameterlijnen"
afb$(3) = "-> Karakteristieke lijnen"
afb$(4) = "-> X Y eenheidsvlakken"
afb$(5) = "-> x y assen"
afb$(6) = "-> Na ieder beeld"
afb$(7) = "-> Meer..."
afb1$(1) = "niet"
afb1$(2) = "scannen"
afb1$(3) = "tonen"
afb1$(4) = "tonen"
afb1$(5) = "tonen"
afb1$(6) = "wachten"
afb1$(7) = ""
afb2$(1) = "wel"
afb2$(2) = "niet scannen"
afb2$(3) = "niet tonen"
afb2$(4) = "niet tonen"
afb2$(5) = "niet tonen"
afb2$(6) = "doorgaan"
afb2$(7) = ""
DIM col(8), scol(9)
DIM afb3$(5)
afb3$(1) = "-> Kenmelodie"
afb3$(2) = "-> Schermkleur"
afb3$(3) = "-> Aantal rotatiebeelden"
afb3$(4) = "-> Max aantal scanbeurten"
afb3$(5) = "-> Scanmodi..."
DIM mel$(2), scr$(4), scrcol(4)
mel$(1) = "PLAY": mel$(2) = "MUTE"
scr$(1) = "donker": scrcol(1) = 0
scr$(2) = "grijs ": scrcol(2) = 8
scr$(3) = "wit   ": scrcol(3) = 7
scr$(4) = "helwit": scrcol(4) = 15
DIM f$(2)

''' DEFAULTinstellingen'''
'''********************'''
FOR i = 1 TO 8: col(i) = 7: NEXT i
FOR i = 1 TO 9: scol(i) = 7: NEXT i
pi = ATN(1) * 4
tit$ = "X en Y -eenheidsassen": c$ = ""
nrot = 9: drot = 360 / nrot: ja$ = "": xy$ = "": curv$ = ""
a = .8
alf = 55: alfr = alf * pi / 180
tta = TAN(alfr): cca = COS(alfr): ssa = SIN(alfr)
b = .7
bet = -40: betr = bet * pi / 180
ttb = TAN(betr): ccb = COS(betr): ssb = SIN(betr)
nr% = 4: scan = 3: scr = 1: mel = 1

'''Intro'''
'''*****'''
intro:
CALL intro

'''Hoofdmenu'''
'''*********'''
menu:
CALL menu
IF men <> 0 GOTO menu

'''Dimensionering'''
'''**************'''
IF fig <> 0 THEN
REDIM x1(mmax, nmax), x2(mmax, nmax), y1(mmax, nmax), y2(mmax, nmax)
REDIM u(mmax, nmax), v(mmax, nmax)
END IF

'''Ruimtecoordinaten figuur'''
'''***********************'''
SELECT CASE fig
CASE 0: max = 2: fac = 1
CASE 1: CALL coorcirkel
CASE 2: CALL coordubhyp
CASE 3: GOSUB datacosec: CALL coorcosec
CASE 4: CALL coorexpon
CASE 5: CALL coorparab
CASE 6: CALL coorcosin
CASE 7: GOSUB datatan: CALL coortan
CASE 8: CALL coorsino
CASE 9: CALL coorsinq
CASE 10: CALL coorcupara
END SELECT

'''Projectiecoordinaten en tekenen figuur'''
'''**************************************'''
tel = 0                          '''eerste scherm'''
SELECT CASE nr%
CASE 1: CALL rot1
CASE 2: CALL rot2
CASE 3: CALL rot3
CASE 4: CALL rot4
CASE 5: CALL rot5
CASE 6: CALL rot6
CASE 7: CALL rot7
CASE 8: CALL rot8
CASE 9: CALL rot9
CASE 10: CALL rot10
CASE 11: CALL rot11
CASE 12: CALL rot12
CASE 13: CALL rot13
END SELECT
PLAY "o4l12d"
LOCATE 1, 60: COLOR 3: PRINT "-> Druk een toets..."
a$ = INPUT$(1)
GOTO menu

'''Data COSECANS'''
'''*************'''
datacosec:

 RESTORE leescosec
 FOR n = 0 TO nmax: READ xx1sec(n): NEXT n
 FOR m = 0 TO mmax: READ xx2sec(m): NEXT m
 
leescosec:
 DATA .003,.02,.04,.05,.06,.07,.08,.1,.12,.14,.16
 DATA .2,.25,.3,.4,.5,.75,1,1.25,1.5

 DATA -5,-4,-3,-2,-1,-.5,-.3,-.2,-.15,-.1,-.08,-.06,-.04,-.02
 DATA .0
 DATA .02,.04,.06,.08,.1,.15,.2,.3,.5,1,2,3,4,5
RETURN

'''Data TANGENS'''
'''************'''
datatan:

 RESTORE leestan
 FOR n = 0 TO nmax: READ xxtan1(n): NEXT n
 FOR m = 0 TO mmax: READ xxtan2(m): NEXT m

leestan:
 DATA .1,.25,.5,.75,1,1.2,1.3,1.4,1.42,1.44,1.46,1.48
 DATA 1.5,1.51,1.52,1.53,1.54,1.55,1.57

 DATA -5,-4,-3,-2,-1,-.5,-.25,-.2,-.15,-.1,-.08,-.06,-.04,-.02
 DATA .0
 DATA .02,.04,.06,.08,.1,.15,.2,.25,.5,1,2,3,4,5

RETURN

END

SUB coorcirkel
	FOR m = 0 TO mmax
	FOR n = 0 TO nmax
	str = r(n): hoek = m * delthoek
	x1(m, n) = str * COS(hoek)
	x2(m, n) = str * SIN(hoek)
	y1(m, n) = (1 / str) * COS(-hoek)
	y2(m, n) = (1 / str) * SIN(-hoek)
	NEXT n
	NEXT m
END SUB

SUB coorcosec
coorcosec:
	FOR n = 0 TO nmax
	FOR m = 0 TO mmax
	x1 = xx1sec(n)
	x2 = xx2sec(m)
	x1(m, n) = x1
	x2(m, n) = x2
	y2 = EXP(-x2) * COS(x1) - EXP(x2) * COS(-x1)
	y1 = EXP(-x2) * SIN(x1) - EXP(x2) * SIN(-x1)
	noem = y1 ^ 2 + y2 ^ 2
	y1(m, n) = 2 * y1 / noem
	y2(m, n) = 2 * y2 / noem
	NEXT m
	NEXT n
END SUB

SUB coorcosin
	FOR n = 0 TO nmax
	FOR m = 0 TO mmax
	x1 = xxsin1(n): x2 = xxsin2(m)
	x1(m, n) = x1
	x2(m, n) = x2
	y1(m, n) = .5 * COS(x1) * (EXP(x2) + EXP(-x2))
	y2(m, n) = -.5 * SIN(x1) * (EXP(x2) - EXP(-x2))
	NEXT m
	NEXT n
END SUB

SUB coorcupara
	FOR m = 0 TO mmax
	FOR n = 0 TO nmax
	str = rcupar(n): hoek = m * delthoek
	x1(m, n) = str * COS(hoek)
	x2(m, n) = str * SIN(hoek)
	y1(m, n) = (str ^ 3) * COS(3 * hoek)
	y2(m, n) = (str ^ 3) * SIN(3 * hoek)
	NEXT n
	NEXT m
END SUB

SUB coordubhyp
	FOR m = 0 TO mmax
	FOR n = 0 TO nmax
	st = rdub(n): hoek = m * delthoek
	x1(m, n) = st * COS(hoek)
	x2(m, n) = st * SIN(hoek)
	y1(m, n) = (.125 / (st * st)) * COS(-2 * hoek)
	y2(m, n) = (.125 / (st * st)) * SIN(-2 * hoek)
	NEXT n
	NEXT m
END SUB

SUB coorexpon
	FOR n = 0 TO nmax
	FOR m = 0 TO mmax
	x1 = xx1exp(n)
	x1(m, n) = x1
	x2(m, n) = -pi + m * deltx2
	x2 = x2(m, n)
	y1(m, n) = EXP(x1) * COS(x2)
	y2(m, n) = EXP(x1) * SIN(x2)
	NEXT m
	NEXT n
END SUB

SUB coorparab
	FOR m = 0 TO mmax
	FOR n = 0 TO nmax
	str = rpar(n): hoek = m * delthoek
	x1(m, n) = str * COS(hoek)
	x2(m, n) = str * SIN(hoek)
	y1(m, n) = (str ^ 2) * COS(2 * hoek)
	y2(m, n) = (str ^ 2) * SIN(2 * hoek)
	NEXT n
	NEXT m
END SUB

SUB coorsino
	rb = 0: re = 1.3: argb = 0: arge = 2 * pi
	FOR n = 0 TO nmax
	FOR m = 0 TO mmax
	r = rb + n * (re - rb) / nmax          '!!!
	arg = argb + m * (arge - argb) / mmax  '!!!
	x1(m, n) = r * COS(arg): x2(m, n) = r * SIN(arg)
	argy = COS(2 * arg) * r ^ 2
	mody = EXP(-SIN(2 * arg) * r ^ 2)
	y1(m, n) = (mody / 2 + 1 / (2 * mody)) * COS(argy) - 1
	y2(m, n) = (mody / 2 - 1 / (2 * mody)) * SIN(argy)
	NEXT m
	NEXT n
END SUB

SUB coorsinq
	rb = 0: re = .5: argb = 0: arge = 2 * pi
	FOR n = 0 TO nmax
	FOR m = 0 TO mmax
	r = rb + n * (re - rb) / nmax           '!!!
	arg = argb + m * (arge - argb) / mmax   '!!!
	x1(m, n) = r * COS(arg): x2(m, n) = r * SIN(arg)
	y1(m, n) = (SIN(2 * pi * r) ^ 2) * COS(arg)
	y2(m, n) = (SIN(2 * pi * r) ^ 2) * SIN(arg)
	NEXT m
	NEXT n
END SUB

SUB coortan
coortan:
	FOR n = 0 TO nmax
	FOR m = 0 TO mmax
	x1 = xxtan1(n)
	x2 = xxtan2(m)
	x1(m, n) = x1
	x2(m, n) = x2
	xi1 = EXP(-x2) * COS(x1): eta1 = EXP(-x2) * SIN(x1)
	xi2 = EXP(x2) * COS(-x1): eta2 = EXP(x2) * SIN(-x1)
	noem = (xi1 + xi2) ^ 2 + (eta1 + eta2) ^ 2
	y1(m, n) = ((eta1 - eta2) * (xi1 + xi2) + (-xi1 + xi2) * (eta1 + eta2)) / noem
	y2(m, n) = (-xi1 ^ 2 + xi2 ^ 2 - eta1 ^ 2 + eta2 ^ 2) / noem
	NEXT m
	NEXT n
END SUB

SUB figuur
SCREEN 12: CLS : COLOR 15
	PRINT "     Keuze van figuur Y=F(X), met X=x1+i*x2;Y=y1+i*y2:"
	PRINT "     ************************************************"
	PRINT : COLOR 7
	FOR i = 0 TO 10: LOCATE i + 4, 15: PRINT ffig$(i): NEXT i

LOCATE 28, 1: COLOR 3: PRINT "     >>> Kies en selecteer figuur met pijltoetsen <<<"

i = fig
in = i
IF mel = 1 THEN PLAY "p21l21o3dp21fp21g"

kiesfig:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verderfig
tijd = TIMER
IF in < 0 THEN in = 10
IF in > 10 THEN in = 0
COLOR 7: LOCATE i + 4, 15: PRINT ffig$(i)
i = in
COLOR 11: LOCATE i + 4, 15: PRINT ffig$(i)

verderfig:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkfig
CASE CHR$(0) + "K": GOTO bewerkfig
CASE CHR$(0) + "M": GOTO bewerkfig
CASE CHR$(0) + "P": in = (i + 1): GOTO kiesfig
CASE CHR$(0) + "H": in = (i - 1): GOTO kiesfig
CASE ELSE: GOTO verderfig
END SELECT

bewerkfig:
fig = i
COLOR 15
CLS : COLOR 15
SELECT CASE fig
CASE 0:
tit$ = "X en Y -eenheidsassen"
c$ = ""
CASE 1:
tit$ = "CIRKEL/HYPERBOOL Y=1/X"
CALL funcirkel
CASE 2
tit$ = "DUBBELHYPERBOOL Y=1/X^2"
CALL fundubhyp
CASE 3
tit$ = "COSECANS"
CALL funcosec
CASE 4
tit$ = "EXPONENTIEEL Y=EXP(X)"
CALL funexpon
CASE 5
tit$ = "PARABOOL Y=X*X"
CALL funparab
CASE 6
tit$ = "COSINUS"
CALL funcosin
CASE 7
tit$ = "TANGENS"
CALL funtangens
CASE 8
tit$ = "SINUOID Ry=SIN(2pi Rx)"
CALL funsino
CASE 9
tit$ = "QUADSIN Y=sin^2 (X)"
CALL funsinq
CASE 10
tit$ = "CUBISCHE PARABOOL Y=X^3"
CALL funcupara
END SELECT

END SUB

SUB figuurtit
LOCATE 28, 1: COLOR 3
PRINT "     >>> Wijzigen=andere waarde typen; bevestigen met ENTER <<<"
LOCATE 1, 15: COLOR 15: PRINT tit$
LOCATE 2, 15: FOR i = 1 TO LEN(tit$): PRINT "*"; : NEXT i: PRINT : PRINT
END SUB

SUB funcirkel
	m = 0: n = 0: nmax = 0
	CALL figuurtit
	COLOR 3
	PRINT "x1 = str * COS(hoek) ; x2 = str * SIN(hoek)"
	PRINT "y1 = (1/str) * COS(-hoek) ; y2 = (1/str) * SIN(-hoek)"
	PRINT
	COLOR 7: PRINT "mmax = aantal parameterlijnen 'hoek' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=18) : ", mmax
	IF mmax = 0 THEN mmax = 18
	COLOR 7: PRINT
	PRINT "deltr0 = stap parameterlijnen 'str' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> deltr0? (default=1) : ", deltr0
	IF deltr0 = 0 THEN deltr0 = 1
	COLOR 7: PRINT
	PRINT "1 = volle figuur"
	PRINT "2 = halve figuur"
	PRINT "4 = kwart figuur"
	COLOR 11: INPUT "  -> Keuze ? (default=1) : ", arge
	IF arge = 0 THEN arge = 1
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1.15) :", fac
	IF fac = 0 THEN fac = 1.15
	COLOR 7
	arge = 2 * pi / arge
	delthoek = arge / mmax
	rstart = .2: rstop = 1 / rstart
	rstop = 4: str = 1
	REDIM r(50)
	r(0) = str: tel = 0
straalcirkel:
	r(n) = str
	deltr = deltr0 * str * str / SQR(1 + str ^ 4)
	str = str + deltr
	IF str > rstop GOTO herschikcirkel
	tel = tel + 1
	n = n + 1
	GOTO straalcirkel

herschikcirkel:
	FOR i = 1 TO n: r(n + i) = r(i): NEXT i: r(n) = r(0)
	FOR i = 1 TO n: r(n - i) = 1 / r(n + i): NEXT i
	nmax = n * 2
END SUB

SUB funcosec
	CALL figuurtit
	COLOR 3
	PRINT "y2 = EXP(-x2) * COS(x1) - EXP(x2) * COS(-x1)"
	PRINT "y1 = EXP(-x2) * SIN(x1) - EXP(x2) * SIN(-x1)"
	PRINT
	COLOR 7: PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=.02) :", fac
	IF fac = 0 THEN fac = .02
	COLOR 7
	k = 0
	m = 0: n = 0: nmax = 20 - 1: mmax = 29 - 1
	x1 = 0: x2 = 0: y1 = 0: y2 = 0
	REDIM xx1sec(nmax), xx2sec(mmax)
END SUB

SUB funcosin
	m = 0: n = 0: nmax = 0: k = 0
	CALL figuurtit
	COLOR 3
	PRINT "= tweebladige EXPONENTIEEL:": PRINT
	PRINT "y1 = .5 * COS(x1) * (EXP(x2) + EXP(-x2))"
	PRINT "y2 = -.5 * SIN(x1) * (EXP(x2) - EXP(-x2))"
	PRINT
	COLOR 7: PRINT "ds1 = afstand parameterlijnen x1 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> ds1? (default=.3) : ", delts1
	IF delts1 = 0 THEN delts1 = .3
	COLOR 7: PRINT
	PRINT "ds2 = afstand parameterlijnen x2 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> ds2? (default=1.5) : ", delts2
	IF delts2 = 0 THEN delts2 = 1.5
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1.1) :", fac
	IF fac = 0 THEN fac = 1.1
	COLOR 7

'''Initiatie Ruimtecoordinaten'''
'''***************************'''
	x1b = -pi: x1e = pi: x2b = -pi: x2e = pi
	x1 = .01: x2 = .01: deltx1 = 0: deltx2 = 0
	REDIM xxsin1(50), xxsin2(50)

x1cosin:
	xxsin1(n) = x1: deltx1 = delts1 / SQR(1 + SIN(x1) ^ 2)
	x1 = x1 + deltx1
	IF x1 > x1e GOTO redox1cosin
	n = n + 1
	GOTO x1cosin

redox1cosin:
	FOR k = 1 TO n: xxsin1(n + k) = xxsin1(k): NEXT k
	xxsin1(n) = xxsin1(0)
	FOR k = 1 TO n: xxsin1(n - k) = -xxsin1(n + k): NEXT k
	xxsin1(0) = x1b: xxsin1(2 * n) = x1e

x2cosin:
	xxsin2(m) = x2
	deltx2 = 2 * delts2 / SQR(EXP(-2 * x2) + EXP(2 * x2) + 2 * EXP(-x2) * EXP(x2) + 4)
	x2 = x2 + deltx2
	IF x2 > x2e GOTO redox2cosin
	m = m + 1
	GOTO x2cosin

redox2cosin:
	FOR k = 1 TO m: xxsin2(m + k) = xxsin2(k): NEXT k
	xxsin2(m) = xxsin2(0)
	FOR k = 1 TO m: xxsin2(m - k) = -xxsin2(m + k): NEXT k
	xxsin2(0) = x2b: xxsin2(2 * m) = x2e

	nmax = n * 2: mmax = m * 2
END SUB

SUB funcupara
	m = 0: n = 0: nmax = 0
	CALL figuurtit
	COLOR 3
	PRINT "x1 = str * COS(hoek) ; x2 = str * SIN(hoek)"
	PRINT "y1 = (str ^ 3) * COS(3 * hoek)"
	PRINT "y2 = (str ^ 3) * SIN(3 * hoek)"
	PRINT
	COLOR 7: PRINT "mmax = aantal parameterlijnen 'hoek' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=36) : ", mmax
	IF mmax = 0 THEN mmax = 36
	COLOR 7: PRINT
	PRINT "deltr0 = stap parameterlijnen 'str' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> deltr0? (default=1) : ", deltr0
	IF deltr0 = 0 THEN deltr0 = 1
	COLOR 7: PRINT
	PRINT "3 = volle figuur"
	PRINT "2 = 2/3 figuur"
	PRINT "1 = 1/3 figuur"
	COLOR 11: INPUT "  -> Keuze ? (default=3) : ", arge
	IF arge = 0 THEN arge = 3
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1.2) :", fac
	IF fac = 0 THEN fac = 1.2
	COLOR 7

'''Initiatie Ruimtecoordinaten'''
'''***************************'''
	rstart = 0!: rstop = 2!: deltr = 0!: str = rstart
	REDIM rcupar(50)
	arge = 2 * pi * arge / 3
	delthoek = arge / mmax

straalcupara:
	rcupar(n) = str: deltr = deltr0 / SQR(1 + 9 * str ^ 4)
	deltr = deltr * (str + .1)  '''=fijner rond 0-punt
	str = str + deltr
	IF str > rstop THEN nmax = n: EXIT SUB
	n = n + 1
	GOTO straalcupara
END SUB

SUB fundubhyp
	m = 0: n = 0: nmax = 0
	CALL figuurtit
	COLOR 3
	PRINT "Y = .125 / X^2 , of"
	PRINT "x1 = str * COS(hoek) ; x2 = str * SIN(hoek)"
	PRINT "y1 = (.125 / (str * str)) * COS(-2 * hoek)"
	PRINT "y2 = (.125 / (str * str)) * SIN(-2 * hoek)"
	PRINT
	COLOR 7: PRINT "mmax = aantal parameterlijnen 'hoek' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=36) : ", mmax
	IF mmax = 0 THEN mmax = 36
	COLOR 7: PRINT
	PRINT "deltr0 = stap parameterlijnen 'str' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> deltr0? (default=.5) : ", deltr0
	IF deltr0 = 0 THEN deltr0 = .5
	COLOR 7: PRINT
	PRINT "1 = volle figuur"
	PRINT "2 = halve figuur"
	PRINT "4 = kwart figuur"
	COLOR 11: INPUT "  -> Keuze ? (default=1) : ", arge
	IF arge = 0 THEN arge = 1
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1) :", fac
	IF fac = 0 THEN fac = 1
	COLOR 7
	arge = 2 * pi / arge
	delthoek = arge / mmax
	rstart = .2: rstop = 3.5: str = rstart
	REDIM rdub(50)

straaldubhyp:
	rdub(n) = str: deltr = deltr0 * 4 * str ^ 3 / SQR(16 * str ^ 6 + 1)
	str = str + deltr
	IF str > rstop THEN nmax = n: EXIT SUB
	n = n + 1
	GOTO straaldubhyp
END SUB

SUB funexpon
	m = 0: n = 0: nmax = 0
	CALL figuurtit
	COLOR 3
	PRINT "y1 = EXP(x1) * COS(x2)"
	PRINT "y2 = EXP(x1) * SIN(x2)"
	PRINT
	COLOR 7: PRINT "mmax = aantal parameterlijnen x2 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=8) : ", mmax
	IF mmax = 0 THEN mmax = 8
	deltx2 = 2 * pi / mmax
	COLOR 7: PRINT
	PRINT "deltx1 = stap parameterlijnen x1 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> deltx1? (default=1) : ", deltx1
	IF deltx1 = 0 THEN deltx1 = 1
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1.2) :", fac
	IF fac = 0 THEN fac = 1.2
	COLOR 7

'''Initiatie Ruimtecoordinaten'''
'''***************************'''
	x1b = -4: x1e = 2: x2b = -pi: x2e = pi
	REDIM xx1exp(50)
	x1 = x1b

x1expon:
	xx1exp(n) = x1: deltx = deltx1 / SQR(1 + EXP(2 * x1))
	x1 = x1 + deltx
	IF x1 > x1e THEN nmax = n: EXIT SUB
	n = n + 1
	GOTO x1expon
END SUB

SUB funparab
	m = 0: n = 0: nmax = 0
	CALL figuurtit
	COLOR 3
	PRINT "x1 = str * COS(hoek) ; x2 = str * SIN(hoek)"
	PRINT "y1 = (str ^ 2) * COS(2 * hoek)"
	PRINT "y2 = (str ^ 2) * SIN(2 * hoek)"
	PRINT
	COLOR 7: PRINT "mmax = aantal parameterlijnen 'hoek' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=24) : ", mmax
	IF mmax = 0 THEN mmax = 24
	COLOR 7: PRINT
	PRINT "deltr0 = stap parameterlijnen 'str' (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> deltr0? (default=.4) : ", deltr0
	IF deltr0 = 0 THEN deltr0 = .4
	COLOR 7: PRINT
	PRINT "1 = volle figuur"
	PRINT "2 = halve figuur"
	PRINT "4 = kwart figuur"
	COLOR 11: INPUT "  -> Keuze ? (default=1) : ", arge
	IF arge = 0 THEN arge = 1
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1.2) :", fac
	IF fac = 0 THEN fac = 1.2
	COLOR 7

'''Initiatie Ruimtecoordinaten'''
'''***************************'''
	rstart = 0!: rstop = 2!: deltr = 0!: str = rstart
	REDIM rpar(50)
	arge = 2 * pi / arge
	delthoek = arge / mmax

straalparab:
'''     rpar(n) = str: deltr = deltr0 * 2 * str ^ 2 / SQR(4 * str ^ 4 + 1)
	rpar(n) = str: deltr = deltr0 / SQR(1 + 4 * str ^ 2)
	str = str + deltr
	IF str > rstop THEN nmax = n: EXIT SUB
	n = n + 1
	GOTO straalparab
END SUB

SUB funsino
	m = 0: n = 0
	CALL figuurtit
	COLOR 3
	PRINT "x1 = r * COS(arg): x2 = r * SIN(arg)"
	PRINT "argy = COS(2 * arg) * r ^ 2"
	PRINT "mody = EXP(-SIN(2 * arg) * r ^ 2)"
	PRINT "y1 = (mody / 2 + 1 / (2 * mody)) * COS(argy) - 1"
	PRINT "y2 = (mody / 2 - 1 / (2 * mody)) * SIN(argy)"
	PRINT
	COLOR 7: PRINT "nmax = aantal parameterlijnen x1 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> nmax? (default=12) : ", nmax
	IF nmax = 0 THEN nmax = 12
	COLOR 7: PRINT
	PRINT "mmax = aantal parameterlijnen x2 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=72) : ", mmax
	IF mmax = 0 THEN mmax = 72
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1) :", fac
	IF fac = 0 THEN fac = 1
	COLOR 7
END SUB

SUB funsinq
	m = 0: n = 0
	CALL figuurtit
	COLOR 3
	PRINT "x1 = r * COS(arg): x2 = r * SIN(arg)"
	PRINT "y1 = (SIN(2 * pi * r) ^ 2) * COS(arg)"
	PRINT "y2 = (SIN(2 * pi * r) ^ 2) * SIN(arg)"
	PRINT
	COLOR 7: PRINT "nmax = aantal parameterlijnen x1 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> nmax? (default=18) : ", nmax
	IF nmax = 0 THEN nmax = 18
	COLOR 7: PRINT
	PRINT "mmax = aantal parameterlijnen x2 (= fijnmazigheid figuur)"
	COLOR 11: INPUT "  -> mmax? (default=18) : ", mmax
	IF mmax = 0 THEN mmax = 18
	COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=1) :", fac
	IF fac = 0 THEN fac = 1
	COLOR 7
END SUB

SUB funtangens
	CALL figuurtit
	COLOR 3
	PRINT "xi1 = EXP(-x2) * COS(x1): eta1 = EXP(-x2) * SIN(x1)"
	PRINT "xi2 = EXP(x2) * COS(-x1): eta2 = EXP(x2) * SIN(-x1)"
	PRINT "noem = (xi1 + xi2) ^ 2 + (eta1 + eta2) ^ 2"
	PRINT "y1 = ((eta1 - eta2) * (xi1 + xi2) + (-xi1 + xi2) * (eta1 + eta2)) / noem"
	PRINT "y2 = (-xi1 ^ 2 + xi2 ^ 2 - eta1 ^ 2 + eta2 ^ 2) / noem"
	PRINT : COLOR 7: PRINT
	PRINT "fac = aanpassingsfactor schermafmetingen :"
	COLOR 11: INPUT "  -> fac ? (default=.0075) :", fac
	IF fac = 0 THEN fac = .0075
	COLOR 7
	m = 0: n = 0: k = 0
	nmax = 19 - 1: mmax = 29 - 1
	x1 = 0: x2 = 0: y1 = 0: y2 = 0
	xi1 = 0: xi2 = 0: eta1 = 0: eta2 = 0: noem = 0
	REDIM xxtan1(nmax), xxtan2(mmax)
END SUB

SUB intro
SCREEN 12: CLS : COLOR 11
IF mel = 1 THEN PLAY "p18l18o3cdfa>c"
PRINT "Welkom in 2D COMPLEXITY land !                               >1/4"
COLOR 7: PRINT : PRINT
PRINT "Dit is een variatie van "; : COLOR 11: PRINT "4D REALITY land"
PRINT : COLOR 7
PRINT "Het herbergt complexe functies van het type Y=F(X)"
PRINT "In reality land komen die overeen met koppels functies"
PRINT "y1=f1(x1,x2); y2=f2(x1,x2), waarbij X=x1+i*x2, Y=y1+i*y2"
PRINT
PRINT "Complexity land (X,Y) is dus een broertje van"
PRINT "reality land (x1,x2,y1,y2)"
PRINT
PRINT "De functie F stelt een 1D part (een kromme) voor van 2D complexity land,"
PRINT "dus haar evenknie (f1,f2) een 2D part (een oppervlak) in 4D reality land"
PRINT
PRINT "Geometrisch niet uit te beelden denkt men dan, want 4D..."
PRINT "Het volstaat echter eraan te denken om dezelfde techniek"
PRINT "toe te passen als voor 3D vlakken op papier:"
PRINT "het traceren van twee families krommen van het oppervlak"
PRINT
PRINT "Vooraf bepalen we wel de projecties van de assen"
PRINT "x1,x2,y1,y2 op het papiervlak (u,v) (welke assen we "
PRINT "in eerste instantie doen samenvallen met die van het "
PRINT "reele vlak x1,y1)"
LOCATE 28, 15: COLOR 3: PRINT ">>> druk een toets <<<"
SLEEP: a$ = INKEY$

CLS : COLOR 11
IF mel = 1 THEN PLAY "l18o3g"
PRINT "Welkom in 2D COMPLEXITY land !                               >2/4"
COLOR 7: PRINT : PRINT
PRINT "Om nu de figuur voor te stellen moeten we de FUNCTIE F,"
PRINT "oftewel de functies f1 en f2 specifieren"
PRINT
PRINT "Vervolgens moeten we geschikte parameterkrommen vinden"
PRINT "Dit is een kwestie van uitproberen, voor elke FUNCTIE"
PRINT "Het resultaat is de berekening van twee "
PRINT "parameterfamilies m en n, zodat x1=x1(m,n), x2=x2(m,n),"
PRINT "en bijhorende y1(m,n) en y2(m,n) waarden een netwerk"
PRINT "van coordinaten gaan vormen"
PRINT
PRINT "Nu gaan we de figuur afbeelden, en ze daarbij doen roteren"
PRINT "Als rotatievlak nemen we een willekeurig paar assen"
PRINT "uit het viertal x1,x2,y1,y2"
PRINT "We kunnen ook twee vlakken tegelijk roteren"
PRINT "Op die manier zijn er dertien rotaties mogelijk"
PRINT
PRINT "Deze rotaties kunnen worden afgebeeld als 'nulfiguur'"
PRINT "ttz als geen andere figuur is geselecteerd"
PRINT
PRINT "Tenslotte kunnen nog lengte en hoek van de "
PRINT "projectieassen x2 en y2 worden gewijzigd"
LOCATE 28, 15: COLOR 3: PRINT ">>> druk een toets <<<"
SLEEP: a$ = INKEY$

CLS : COLOR 11
IF mel = 1 THEN PLAY "l18o3e"
PRINT "Welkom in 2D COMPLEXITY land !                               >3/4"
COLOR 7: PRINT : PRINT
PRINT "Zoals mag worden verwacht blijkt bij het afbeelden van een"
PRINT "complexe FUNCTIE dat algebraisch verwante reele functies hier"
PRINT "deelverzamelingen van zijn"
PRINT
PRINT "Zo blijken cirkel en hyperbool (algebraisch-complex identiek)"
PRINT "parameterkrommen te zijn van de complexe CIRKEL (of HYPERBOOL)"
PRINT "Andere voorbeelden zijn, voor de COSINUS: de cosinus, de cosh"
PRINT "en de sinh (hyperbolische sin en cos);"
PRINT "voor de TANGENS: de tan, tanh en cotanh; enzovoort"
PRINT
PRINT "Optioneel kunnen deze specifieke krommen extra worden belicht,"
PRINT "naargelang de figuur"
PRINT
PRINT "Andere opties, ongeacht de figuur, omvatten "
PRINT "het aantal stappen per rotatie,"
PRINT "het al dan niet stoppen na elk beeld,"
PRINT "het al dan niet tonen van de eenheidsassen of -vlakken"
PRINT "het al dan niet scannen van de parameterkrommen"
LOCATE 28, 15: COLOR 3: PRINT ">>> druk een toets <<<"
SLEEP: a$ = INKEY$

CLS : COLOR 11
IF mel = 1 THEN PLAY "l18o3c"
PRINT "Welkom in 2D COMPLEXITY land !                               >4/4"
PRINT : PRINT : COLOR 15
PRINT "Veel plezier met het bewonderen van 4D objecten!!!"
PRINT : PRINT : COLOR 7
PRINT "PS: Wie hierover meer ideeen heeft of anderszins"
PRINT "creatieve wiskunde bedrijft wordt vriendelijk uitgenodigd"
PRINT "over zijn bevindingen te corresponderen met de auteur "
PRINT : COLOR 10
LOCATE 25, 14
PRINT "Credits: guido wuyts 1995"
LOCATE 28, 15: COLOR 3: PRINT ">>> druk een toets <<<"
SLEEP: a$ = INKEY$: a$ = ""
END SUB

SUB melo
COLOR 11

kiesmelo:
IF mel < 1 THEN mel = 2
IF mel > 2 THEN mel = 1
LOCATE 4, 48: PRINT mel$(mel)

Verdermelo:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkmelo
CASE CHR$(0) + "P": mel = mel - 1: GOTO kiesmelo
CASE CHR$(0) + "H": mel = mel + 1: GOTO kiesmelo
CASE CHR$(0) + "K": mel = mel - 1: GOTO kiesmelo
CASE CHR$(0) + "M": mel = mel + 1: GOTO kiesmelo
CASE ELSE: GOTO Verdermelo
END SELECT

bewerkmelo:
COLOR 7
LOCATE 4, 48: PRINT mel$(mel)
END SUB

SUB menu
SCREEN 12
	CLS : COLOR 15
	LOCATE 1, 16: PRINT tit$
	c$ = "": FOR i = 1 TO LEN(tit$): c$ = c$ + "*": NEXT i
	LOCATE 2, 16: PRINT c$
	mentot = 6
	COLOR 7: FOR i = 0 TO mentot: LOCATE i + 4, 14: PRINT fmen$(i): NEXT i
       
LOCATE 28, 1: COLOR 3: PRINT "     >>> Kies en selecteer optie met pijltoetsen <<<"
jn = 0: j = 0
IF mel = 1 THEN PLAY "l21o3cp21gp21>c"

kiesmenu:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verdermenu
tijd = TIMER
IF jn = -1 THEN jn = mentot
COLOR 7: LOCATE j + 4, 14: PRINT fmen$(j)
j = jn
COLOR 11: LOCATE j + 4, 14: PRINT fmen$(j)

verdermenu:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkmenu
CASE CHR$(0) + "K": GOTO bewerkmenu
CASE CHR$(0) + "M": GOTO bewerkmenu
CASE CHR$(0) + "P": jn = (j + 1) MOD (mentot + 1): GOTO kiesmenu
CASE CHR$(0) + "H": jn = (j - 1) MOD (mentot + 1): GOTO kiesmenu
CASE ELSE: GOTO verdermenu
END SELECT

bewerkmenu:
men = j
SELECT CASE men
CASE 0
COLOR 3: LOCATE 28, 5: PRINT " >>> Even geduld...                                 "
COLOR 15: LOCATE 25, 5: PRINT " >>> Berekening van figuur <<<           "
CALL prefscol
EXIT SUB
CASE 1: CALL figuur: EXIT SUB
CASE 2: CALL rotkeus: EXIT SUB
CASE 3: CALL projas: EXIT SUB
CASE 4: CALL prefs: EXIT SUB
CASE 5: CALL intro
CASE ELSE  '''(mentot =  -> END) '''
IF mel = 1 THEN PLAY "l21o3c"
LOCATE 28, 1: COLOR 0: PRINT "     >>> Kies optie met cursortoetsen <<<"
LOCATE 28, 1: COLOR 3
COLOR 3: LOCATE 28, 5: PRINT " >>> ENTER = Niet stoppen <<<                       "
COLOR 15: LOCATE 25, 5: PRINT "        Bent u zeker ?"
SLEEP: a$ = INKEY$
IF a$ <> CHR$(13) THEN
IF mel = 1 THEN PLAY "p18l18o4c<gfdc"
END
END IF
COLOR 0: LOCATE 25, 5: PRINT "        Bent u zeker ?"
LOCATE 28, 1: COLOR 3: PRINT "     >>> Kies en selecteer optie met pijltoetsen <<<"
IF mel = 1 THEN PLAY "l21o3cp21gp21>c"
GOTO verdermenu
END SELECT
END SUB

SUB prefs
SCREEN 12: CLS : COLOR 15
PRINT "               Voorkeurinstellingen "
PRINT "               ********************"
LOCATE 28, 1: COLOR 3
PRINT "     >>> Kies en toggel optie met pijltoetsen; bevestig met ENTER <<<"
COLOR 7
FOR i = 1 TO 7: LOCATE 3 + i, 15: PRINT afb$(i): NEXT i
FOR i = 1 TO 7: LOCATE 3 + i, 45: COLOR col(i): PRINT afb1$(i): NEXT i
FOR i = 1 TO 7: LOCATE 3 + i, 55: COLOR 18 - col(i): PRINT afb2$(i): NEXT i

i = 1
in = i
IF mel = 1 THEN PLAY "p21l21o3fp21gp21c"

kiesafb:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verderafb
tijd = TIMER
IF in < 1 THEN in = 7
IF in > 7 THEN in = 1
COLOR 7: LOCATE i + 3, 15: PRINT afb$(i)
i = in
COLOR 11: LOCATE i + 3, 15: PRINT afb$(i)

verderafb:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): EXIT SUB '''GOTO bewerkafb
CASE CHR$(0) + "K": GOTO bewerkafb
CASE CHR$(0) + "M": GOTO bewerkafb
CASE CHR$(0) + "P": in = (i + 1): GOTO kiesafb
CASE CHR$(0) + "H": in = (i - 1): GOTO kiesafb
CASE ELSE: GOTO verderafb
END SELECT

bewerkafb:
col(i) = 18 - col(i)
LOCATE 3 + i, 45: COLOR col(i): PRINT afb1$(i)
LOCATE 3 + i, 55: COLOR 18 - col(i): PRINT afb2$(i)
IF i = 7 THEN CALL prefsmore: EXIT SUB
GOTO verderafb
END SUB

SUB prefscol
IF scr < 3 THEN
colm = 6: coln = 3: colmm = 12: colnn = 11
colx = 11: coly = 13
colcrv1 = 10: colcrv2 = 9: colcrv3 = 14
ELSE
colm = 4: coln = 1: colmm = 14: colnn = 11
colx = 3: coly = 5
colcrv1 = 2: colcrv2 = 13: colcrv3 = 12
END IF
END SUB

SUB prefsmore
SCREEN 12: CLS : COLOR 15
PRINT "               Voorkeurinstellingen (vervolg)"
PRINT "               ******************************"
LOCATE 28, 1: COLOR 3
PRINT "     >>> Kies en wijzig optie met pijltoetsen; bevestig met ENTER <<<"
COLOR 7
FOR i = 1 TO 5: LOCATE 3 + i, 15: PRINT afb3$(i): NEXT i
LOCATE 4, 48: PRINT mel$(mel)
LOCATE 5, 48: PRINT scr$(scr)
LOCATE 6, 45: PRINT USING "#### x ####.##ø"; nrot; drot
LOCATE 7, 45: PRINT USING "#### "; scan

i = 1
in = i
IF mel = 1 THEN PLAY "p21l21o3fp21gp21c"

kiesafb3:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verderafb3
tijd = TIMER
IF in < 1 THEN in = 5
IF in > 5 THEN in = 1
COLOR 7: LOCATE i + 3, 15: PRINT afb3$(i)
i = in
COLOR 11: LOCATE i + 3, 15: PRINT afb3$(i)

verderafb3:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): EXIT SUB
CASE CHR$(0) + "K": GOTO bewerkafb3
CASE CHR$(0) + "M": GOTO bewerkafb3
CASE CHR$(0) + "P": in = (i + 1): GOTO kiesafb3
CASE CHR$(0) + "H": in = (i - 1): GOTO kiesafb3
CASE ELSE: GOTO verderafb3
END SELECT

bewerkafb3:
SELECT CASE i
CASE 1: CALL melo
CASE 2: CALL schermkleur
CASE 3: CALL rotstap
CASE 4: CALL scanmax
CASE 5: CALL scanmod
END SELECT
GOTO verderafb3
END SUB

SUB projas
CLS :  SCREEN 12
xy = 1.3: WINDOW (-2 * xy, -2)-(2 * xy, 2)
COLOR 15: PRINT "     Keuze projectieassen "; :
COLOR 11: PRINT "x2 "; : COLOR 15: PRINT "en "; : COLOR 13: PRINT "y2 "
COLOR 15: PRINT "     *****************************"
LOCATE 26, 1: COLOR 3
PRINT "     >>> Wijzig lengte met '+' en '-' <<<"
PRINT "     >>>    hoek met cursortoetsen    <<<"
PRINT "     >>>      bevestig met ENTER      <<<"
LOCATE 7, 1: COLOR 7: PRINT "Len y2 = "; : PRINT USING "#.##"; b
LOCATE 8, 1: PRINT "Arg y2 = "; : PRINT USING "#### ø"; bet
IF mel = 1 THEN PLAY "p21l21o3gp21fp21e"

'x2-as
'*****
an = a: alfr = alf * pi / 180: alfn = alf

kiesalf:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verderalf
tijd = TIMER
IF an < 0 THEN an = 0
LINE (0, 0)-(a * COS(alfr), a * SIN(alfr)), 0
alf = alfn: a = an: alfr = alf * pi / 180
LOCATE 4, 1: COLOR 7: PRINT "Len x2 = "; : COLOR 11: PRINT USING "#.##"; a
LOCATE 5, 1: COLOR 7: PRINT "Arg x2 = "; : COLOR 11: PRINT USING "#### ø"; alf
LINE (0, 0)-(0, 1), 7: LINE (0, 0)-(1, 0), 3
LINE (0, 0)-(b * ccb, b * ssb), 7
LINE (0, 0)-(a * COS(alfr), a * SIN(alfr)), 11

verderalf:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13)
GOTO bewerkalf
CASE CHR$(0) + "K": alfn = alf - 1: GOTO kiesalf
CASE CHR$(0) + "M": alfn = alf + 1: GOTO kiesalf
CASE CHR$(0) + "P": alfn = alf - 10: GOTO kiesalf
CASE CHR$(0) + "H": alfn = alf + 10: GOTO kiesalf
CASE "-": an = a - .05: GOTO kiesalf
CASE "+": an = a + .05: GOTO kiesalf
CASE ELSE: GOTO verderalf
END SELECT

bewerkalf:
alfr = alf * pi / 180
tta = TAN(alfr): cca = COS(alfr): ssa = SIN(alfr)

'y2-as
'*****
bn = b
betr = bet * pi / 180: betn = bet

kiesbet:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verderbet
tijd = TIMER
IF bn < 0 THEN bn = 0
LINE (0, 0)-(b * COS(betr), b * SIN(betr)), 0
bet = betn: b = bn: betr = bet * pi / 180
LOCATE 7, 1: COLOR 7: PRINT "Len y2 = "; : COLOR 13: PRINT USING "#.##"; b
LOCATE 8, 1: COLOR 7: PRINT "Arg y2 = "; : COLOR 13: PRINT USING "#### ø"; bet
LINE (0, 0)-(0, 1), 5: LINE (0, 0)-(1, 0), 7
LINE (0, 0)-(a * cca, a * ssa), 7
LINE (0, 0)-(b * COS(betr), b * SIN(betr)), 13

verderbet:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13)
GOTO bewerkbet
CASE CHR$(0) + "K": betn = bet - 1: GOTO kiesbet
CASE CHR$(0) + "M": betn = bet + 1: GOTO kiesbet
CASE CHR$(0) + "P": betn = bet - 10: GOTO kiesbet
CASE CHR$(0) + "H": betn = bet + 10: GOTO kiesbet
CASE "-": bn = b - .05: GOTO kiesbet
CASE "+": bn = b + .05: GOTO kiesbet
CASE ELSE: GOTO verderbet
END SELECT

bewerkbet:
betr = bet * pi / 180
ttb = TAN(betr): ccb = COS(betr): ssb = SIN(betr)
END SUB

SUB rot1
rot$ = "rotatie 1: x1-as alleen"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci: v1 = ssi
u2 = a * cca: v2 = a * ssa
u3 = 0: v3 = 1
u4 = b * ccb: v4 = b * ssb
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''(u,v)'''
CALL tekenen     '''figuur FOR xi'''
END SELECT
NEXT xi
END SUB

SUB rot10
rot$ = "rotatie 10: x2-y1 vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = 1: v1 = 0
u2 = a * cca * cci: v2 = a * ssa * cci + ssi
u3 = -a * cca * ssi: v3 = -a * ssa * ssi + cci
u4 = b * ccb: v4 = b * ssb
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot11
rot$ = "rotatie 11: X-vlak & Y-vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci + a * cca * ssi: v1 = a * ssa * ssi
u2 = -ssi + a * cca * cci: v2 = a * ssa * cci
u3 = b * ccb * ssi: v3 = cci + b * ssb * ssi
u4 = b * ccb * cci: v4 = -ssi + b * ssb * cci
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot12
rot$ = "rotatie 12: x1-y1 & x2-y2 vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci: v1 = ssi
u2 = a * cca * cci + b * ccb * ssi: v2 = a * ssa * cci + b * ssb * ssi
u3 = -ssi: v3 = cci
u4 = -a * cca * ssi + b * ccb * cci: v4 = -a * ssa * ssi + b * ssb * cci
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot13
rot$ = "rotatie 13: x1-y2 & x2-y1 vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci + b * ccb * ssi: v1 = b * ssb * ssi
u2 = a * cca * cci: v2 = a * ssa * cci + ssi
u3 = -a * cca * ssi: v3 = -a * ssa * ssi + cci
u4 = -ssi + b * ccb * cci: v4 = b * ssb * cci
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot2
rot$ = "rotatie 2: y1-as alleen"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = 1: v1 = 0
u2 = a * cca: v2 = a * ssa
u3 = -ssi: v3 = cci
u4 = b * ccb: v4 = b * ssb
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot3
rot$ = "rotatie 3: x2-as alleen"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = 1: v1 = 0
u2 = a * COS(alfr + xxi): v2 = a * SIN(alfr + xxi)
u3 = 0: v3 = 1
u4 = b * ccb: v4 = b * ssb
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot4
rot$ = "rotatie 4: y2-as alleen"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = 1: v1 = 0
u2 = a * cca: v2 = a * ssa
u3 = 0: v3 = 1
u4 = b * COS(betr + xxi): v4 = b * SIN(betr + xxi)
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot5
rot$ = "rotatie 5: X-vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci + a * cca * ssi: v1 = a * ssa * ssi
u2 = -ssi + a * cca * cci: v2 = a * ssa * cci
u3 = 0: v3 = 1
u4 = b * ccb: v4 = b * ssb
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot6
rot$ = "rotatie 6: Y-vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = 1: v1 = 0
u2 = a * cca: v2 = a * ssa
u3 = b * ccb * ssi: v3 = cci + b * ssb * ssi
u4 = b * ccb * cci: v4 = -ssi + b * ssb * cci
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot7
rot$ = "rotatie 7: x1-y1 vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci: v1 = ssi
u2 = a * cca: v2 = a * ssa
u3 = -ssi: v3 = cci
u4 = b * ccb: v4 = b * ssb
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot8
rot$ = "rotatie 8: x2-y2 vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = 1: v1 = 0        ''' vaste as
u2 = a * cca * cci + b * ccb * ssi: v2 = a * ssa * cci + b * ssb * ssi
u3 = 0: v3 = 1        ''' vaste as
u4 = -a * cca * ssi + b * ccb * cci: v4 = -a * ssa * ssi + b * ssb * cci
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rot9
rot$ = "rotatie 9: x1-y2 vlak"
FOR xi = 0 TO 360 STEP drot
xxi = xi * pi / 180
ssi = SIN(xxi): cci = COS(xxi)
u1 = cci + b * ccb * ssi: v1 = b * ssb * ssi
u2 = a * cca: v2 = a * ssa
u3 = 0: v3 = 1
u4 = -ssi + b * ccb * cci: v4 = b * ssb * cci
SELECT CASE fig
CASE 0:
CALL tekenxy    '''assen X en Y'''
CASE ELSE:
CALL tekencoord  '''u,v'''
CALL tekenen     '''figuur(xi)'''
END SELECT
NEXT xi
END SUB

SUB rotkeus
SCREEN 12
	CLS : COLOR 15
	PRINT "               Keuze van type rotatie :"
	PRINT "               ************************"
	PRINT : COLOR 7
	FOR i = 1 TO 13: LOCATE i + 4, 15: PRINT frot$(i): NEXT i
	PRINT


LOCATE 28, 1: COLOR 3: PRINT "     >>> Kies rotatienr. met cursortoetsen <<<"
i = nr%: in = i
IF mel = 1 THEN PLAY "l21o3ap21fp21d"

kiesrot:
IF in = 0 THEN in = 13
COLOR 7: LOCATE i + 4, 15: PRINT frot$(i)
i = in
COLOR 11: LOCATE i + 4, 15: PRINT frot$(i)

Verderrot:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkrot
CASE CHR$(0) + "K": GOTO bewerkrot
CASE CHR$(0) + "M": GOTO bewerkrot
CASE CHR$(0) + "P": in = (i + 1) MOD 13: GOTO kiesrot
CASE CHR$(0) + "H": in = (i - 1) MOD 13: GOTO kiesrot
CASE ELSE: GOTO Verderrot
END SELECT

bewerkrot:
nr% = i
END SUB

SUB rotstap
COLOR 3
LOCATE 20, 1
PRINT "> lagere waarden (minder stappen) voor afbeelden figuren"
PRINT "> hogere (meer stappen) voor afbeelden eenheidsassen"
PRINT "> druk op ESCAPE tijdens opbouw figuur om een reeks te onderbreken"
COLOR 11

kiesstap:
IF nrot <= 0 THEN nrot = 1
IF nrot > 360 THEN nrot = 360
drot = (360 / nrot)
LOCATE 6, 45: PRINT USING "#### x ####.##ø"; nrot; drot

Verderstap:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkstap
CASE CHR$(0) + "P": nrot = nrot - 10: GOTO kiesstap
CASE CHR$(0) + "H": nrot = nrot + 10: GOTO kiesstap
CASE CHR$(0) + "K": nrot = nrot - 1: GOTO kiesstap
CASE CHR$(0) + "M": nrot = nrot + 1: GOTO kiesstap
CASE ELSE: GOTO Verderstap
END SELECT

bewerkstap:
COLOR 7
LOCATE 6, 45: PRINT USING "#### x ####.##ø"; nrot; drot
COLOR 0
LOCATE 20, 1
PRINT "> lagere waarden (minder stappen) voor afbeelden figuren"
PRINT "> hogere (meer stappen) voor afbeelden eenheidsassen"
PRINT "> druk op ESCAPE tijdens opbouw figuur om een reeks te onderbreken"
END SUB

SUB scanmax
COLOR 11

kiesscan:
IF scan <= 0 THEN scan = 1
IF scan > 9 THEN scan = 9
LOCATE 7, 45: PRINT USING "#### "; scan

Verderscan:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkscan
CASE CHR$(0) + "P": scan = scan - 1: GOTO kiesscan
CASE CHR$(0) + "H": scan = scan + 1: GOTO kiesscan
CASE CHR$(0) + "K": scan = scan - 1: GOTO kiesscan
CASE CHR$(0) + "M": scan = scan + 1: GOTO kiesscan
CASE ELSE: GOTO Verderscan
END SELECT

bewerkscan:
COLOR 7
LOCATE 7, 45: PRINT USING "#### "; scan

END SUB

SUB scanmod
COLOR 15
LOCATE 11, 1: PRINT "              Scanbeurt:     Gescande lijnen:"
COLOR 7
FOR i = 1 TO 9: LOCATE 12 + i, 19: PRINT USING ">##"; i: NEXT i
FOR i = 1 TO 9: LOCATE 12 + i, 29: COLOR scol(i): PRINT "wissen": NEXT i
FOR i = 1 TO 9: LOCATE 12 + i, 39: COLOR 18 - scol(i): PRINT "herstellen": NEXT i

i = 1
in = i

kiesscmod:
IF INKEY$ = a$ AND TIMER - tijd < .1 GOTO verderscmod
tijd = TIMER
IF in < 1 THEN in = 9
IF in > 9 THEN in = 1
COLOR 7: LOCATE 12 + i, 19: PRINT USING ">##"; i
i = in
COLOR 11: LOCATE 12 + i, 19: PRINT USING ">##"; i

verderscmod:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13)
COLOR 0
LOCATE 11, 1: PRINT "              Scanbeurt:     Gescande lijnen:"
FOR i = 1 TO 9: LOCATE 12 + i, 19: PRINT USING ">##"; i: NEXT i
FOR i = 1 TO 9: LOCATE 12 + i, 29:  PRINT "wissen": NEXT i
FOR i = 1 TO 9: LOCATE 12 + i, 39:  PRINT "herstellen": NEXT i
EXIT SUB '''GOTO bewerkafb
CASE CHR$(0) + "K": GOTO bewerkscmod
CASE CHR$(0) + "M": GOTO bewerkscmod
CASE CHR$(0) + "P": in = (i + 1): GOTO kiesscmod
CASE CHR$(0) + "H": in = (i - 1): GOTO kiesscmod
CASE ELSE: GOTO verderscmod
END SELECT

bewerkscmod:
scol(i) = 18 - scol(i)
LOCATE 12 + i, 29: COLOR scol(i): PRINT "wissen"
LOCATE 12 + i, 39: COLOR 18 - scol(i): PRINT "herstellen"
GOTO verderscmod
END SUB

SUB scherm
PLAY "o4l12d"
SCREEN 12
yx = 1.3   '''behoud X/Y verhoudingen'''
WINDOW (-max * yx, -max)-(max * yx, max)
END SUB

SUB schermkleur
COLOR 11

kiesscrn:
IF scr < 1 THEN scr = 1
IF scr > 4 THEN scr = 4
LOCATE 5, 48: PRINT scr$(scr)

Verderscrn:
SLEEP: a$ = INKEY$
SELECT CASE a$
CASE CHR$(13): GOTO bewerkscrn
CASE CHR$(0) + "P": scr = scr - 1: GOTO kiesscrn
CASE CHR$(0) + "H": scr = scr + 1: GOTO kiesscrn
CASE CHR$(0) + "K": scr = scr - 1: GOTO kiesscrn
CASE CHR$(0) + "M": scr = scr + 1: GOTO kiesscrn
CASE ELSE: GOTO Verderscrn
END SELECT

bewerkscrn:
COLOR 7
LOCATE 5, 48: PRINT scr$(scr)
END SUB

SUB tekencoord
	max = 0
	FOR m = 0 TO mmax
	FOR n = 0 TO nmax
	u(m, n) = x1(m, n) * u1 + x2(m, n) * u2 + y1(m, n) * u3 + y2(m, n) * u4
	v(m, n) = x1(m, n) * v1 + x2(m, n) * v2 + y1(m, n) * v3 + y2(m, n) * v4
	IF max < ABS(u(m, n)) THEN max = ABS(u(m, n))
	IF max < ABS(v(m, n)) THEN max = ABS(v(m, n))
	NEXT n
	NEXT m
max = max * fac * 1.02            '''reserve'''
END SUB

SUB tekencurv
SELECT CASE fig
CASE 1
 LOCATE 2, 27: COLOR colcrv2: PRINT "cirkel   ";
 COLOR colcrv1: PRINT "hyperbool": COLOR 7
 nn = INT(nmax / 2): mm = INT(mmax / 2)
 FOR m = 0 TO mmax - 1
 LINE (u(m, nn), v(m, nn))-(u(m + 1, nn), v(m + 1, nn)), colcrv2
 NEXT m
 FOR n = 0 TO nmax - 1
 LINE (u(0, n), v(0, n))-(u(0, n + 1), v(0, n + 1)), colcrv1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv1
 NEXT n
CASE 2
 LOCATE 2, 27: COLOR colcrv2: PRINT "kernlus   ";
 COLOR colcrv1: PRINT "'hyperbool'": COLOR 7
 nn = INT(nmax / 2): mm = INT(mmax / 2)
 FOR m = 0 TO mmax - 1
 LINE (u(m, nn), v(m, nn))-(u(m + 1, nn), v(m + 1, nn)), colcrv2
 NEXT m
 FOR n = 0 TO nmax - 1
 LINE (u(0, n), v(0, n))-(u(0, n + 1), v(0, n + 1)), colcrv1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv1
 NEXT n
CASE 3
 LOCATE 2, 27: COLOR colcrv2: PRINT "sech   ";
 COLOR colcrv3: PRINT "cosecans   ";
 COLOR colcrv1: PRINT "ñ cosech": COLOR 7
 mm = INT(mmax / 2)
 FOR m = 0 TO mmax - 1
 LINE (u(m, nmax), v(m, nmax))-(u(m + 1, nmax), v(m + 1, nmax)), colcrv2
 LINE (u(m, 0), v(m, 0))-(u(m + 1, 0), v(m + 1, 0)), colcrv1
 NEXT m
 FOR n = 0 TO nmax - 1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv3
 NEXT n
CASE 4
 LOCATE 2, 27: COLOR colcrv1: PRINT "exponentieel"
 mm = INT(mmax / 2)
 FOR n = 0 TO nmax - 1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv1
 NEXT n
CASE 5
 LOCATE 2, 27: COLOR colcrv1: PRINT "parabool"
 mm = INT(mmax / 2)
 FOR n = 0 TO nmax - 1
 LINE (u(0, n), v(0, n))-(u(0, n + 1), v(0, n + 1)), colcrv1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv1
 NEXT n
CASE 6
 LOCATE 2, 27: COLOR colcrv3: PRINT "cosinus   ";
 COLOR colcrv1: PRINT "cosh   ";
 COLOR colcrv2: PRINT "sinh": COLOR 7
 mm = INT(mmax / 2)
 nn2 = INT(nmax / 2): nn3 = INT(nmax * .75): nn1 = INT(nmax / 4)
 FOR n = 0 TO nmax - 1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv3
 NEXT n
 FOR m = 0 TO mmax - 1
 LINE (u(m, nmax), v(m, nmax))-(u(m + 1, nmax), v(m + 1, nmax)), colcrv1
 LINE (u(m, 0), v(m, 0))-(u(m + 1, 0), v(m + 1, 0)), colcrv1
 LINE (u(m, nn2), v(m, nn2))-(u(m + 1, nn2), v(m + 1, nn2)), colcrv1
 LINE (u(m, nn1), v(m, nn1))-(u(m + 1, nn1), v(m + 1, nn1)), colcrv2
 LINE (u(m, nn3), v(m, nn3))-(u(m + 1, nn3), v(m + 1, nn3)), colcrv2
 NEXT m
CASE 7
 LOCATE 2, 27: COLOR colcrv1: PRINT "tanh   ";
 COLOR colcrv3: PRINT "tangens   ";
 COLOR colcrv2: PRINT "ñ cotanh": COLOR 7
 mm = INT(mmax / 2)
 FOR m = 0 TO mmax - 1
 LINE (u(m, nmax), v(m, nmax))-(u(m + 1, nmax), v(m + 1, nmax)), colcrv2
 LINE (u(m, 0), v(m, 0))-(u(m + 1, 0), v(m + 1, 0)), colcrv1
 NEXT m
 FOR n = 0 TO nmax - 1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv3
 NEXT n
CASE 10
 LOCATE 2, 27: COLOR colcrv1: PRINT "cubische parabool"
 mm = INT(mmax / 2)
 FOR n = 0 TO nmax - 1
 LINE (u(0, n), v(0, n))-(u(0, n + 1), v(0, n + 1)), colcrv1
 LINE (u(mm, n), v(mm, n))-(u(mm, n + 1), v(mm, n + 1)), colcrv1
 NEXT n
END SELECT
END SUB

SUB tekenen
	tel = tel + 1: vlag = 0: a$ = ""
	IF tel = 1 THEN CALL scherm
	CLS
	IF scr > 1 THEN PAINT (0, 0), scrcol(scr)
	LOCATE 1, 1
PRINT "                                                                                "
PRINT "                                                                                "
	LOCATE 1, 1: COLOR 7
	PRINT USING "###/### :####ø rot. ##"; tel - 1; nrot; xi; nr%
	LOCATE 1, 27: COLOR 7: PRINT tit$;
	rij = CSRLIN: kol = POS(0)

'''figuur opbouwen'''
'''***************'''
IF col(1) = 7 THEN CALL tekenfig

''' assenvlakken'''
'''*************'''
IF col(4) = 11 THEN vlagxy = 1: CALL tekenxyvlak

'''assen'''
'''*****'''
IF col(5) = 11 THEN CALL tekenxyas

'''wachtlus'''
'''********'''
FOR dum = 1 TO 2000: NEXT dum
vlagxy = 0

'''ESCAPE=STOP'''
'''***********'''
IF vlag = 1 THEN vlag = 0:  xi = 360: EXIT SUB

'''parameterfamilies tonen'''
'''***********************'''
IF col(2) = 11 THEN CALL tekenparm

'''ESCAPE=STOP'''
'''***********'''
IF vlag = 1 THEN vlag = 0:  xi = 360: EXIT SUB

'''Curven tekenen'''
'''**************'''
IF col(3) = 11 THEN CALL tekencurv

'''wachtlus'''
'''********'''
FOR dum = 1 TO 2000: NEXT dum

'''Stoppen na elk beeld'''
'''********************'''
IF col(6) = 11 THEN
LOCATE 1, 60: COLOR 3: PRINT "-> Druk een toets..."
IF mel = 1 THEN PLAY "l21o3c"
SLEEP: a$ = INKEY$: PLAY "o4l12d"
IF a$ = CHR$(27) THEN col(6) = 7
LOCATE 1, 60: COLOR 3: PRINT ">>> Even geduld...  "
END IF

END SUB

SUB tekenfig
	FOR m = 0 TO mmax - 1
	FOR n = 0 TO nmax - 1
	LINE (u(m, n), v(m, n))-(u(m, n + 1), v(m, n + 1)), colm
	LINE (u(m, n), v(m, n))-(u(m + 1, n), v(m + 1, n)), coln
	NEXT n
	IF vlag = 0 THEN a$ = INKEY$
	IF a$ = CHR$(27) THEN
	a$ = ""
	vlag = 1
	LOCATE 1, 60: COLOR 3: PRINT ">>> Even geduld...  "
	LOCATE rij, kol
	PLAY "o4l12d"
	END IF
	LINE (u(m, nmax), v(m, nmax))-(u(m + 1, nmax), v(m + 1, nmax)), coln
	NEXT m
'''voor goniom. functies'''
'''*********************'''
	IF fig > 2 AND fig <> 5 THEN
	FOR n = 0 TO nmax - 1
	LINE (u(mmax, n), v(mmax, n))-(u(mmax, n + 1), v(mmax, n + 1)), colm
	NEXT n
	END IF

END SUB

SUB tekenparm
	LOCATE 2, 27: COLOR colmm: PRINT "Parameterkrommen M";
	LOCATE 1, 60: COLOR 3: PRINT "-> Druk een toets..."
	vlag = 0: a$ = "": telscan = 1
fam1:
	IF scol(telscan) = 7 THEN scolm = colm ELSE scolm = scrcol(scr)
	FOR n = 0 TO nmax - 1
	LINE (u(0, n), v(0, n))-(u(0, n + 1), v(0, n + 1)), colmm
	NEXT n
	FOR dum = 1 TO 200: NEXT dum
      
	FOR m = 0 TO mmax - 1
      
	FOR n = 0 TO nmax - 1
	LINE (u(m, n), v(m, n))-(u(m, n + 1), v(m, n + 1)), scolm '''colm
	LINE (u(m + 1, n), v(m + 1, n))-(u(m + 1, n + 1), v(m + 1, n + 1)), colmm
	NEXT n
	FOR dum = 1 TO 200: NEXT dum
      
	IF vlag = 0 THEN a$ = INKEY$
	IF a$ = CHR$(27) THEN vlag = 1: EXIT SUB
	IF a$ <> "" THEN
	a$ = ""
	vlag = 1
	LOCATE 1, 60: COLOR 3: PRINT ">>> Even geduld...  "
	PLAY "o4l12d"
	END IF
      
	NEXT m
      
	FOR n = 0 TO nmax - 1
	LINE (u(mmax, n), v(mmax, n))-(u(mmax, n + 1), v(mmax, n + 1)), scolm '''colm
	NEXT n
     
	telscan = telscan + 1
	IF vlag = 0 AND telscan <= scan GOTO fam1
      
'        IF a$ = CHR$(27) THEN EXIT SUB
	vlag = 0: telscan = 1
	LOCATE 2, 27: COLOR colnn: PRINT "Parameterkrommen N";
	LOCATE 1, 60: COLOR 3: PRINT "-> Druk een toets..."
fam2:
	IF scol(telscan) = 7 THEN scoln = coln ELSE scoln = scrcol(scr)
	FOR m = 0 TO mmax - 1
	LINE (u(m, 0), v(m, 0))-(u(m + 1, 0), v(m + 1, 0)), colnn
	NEXT m
	FOR dum = 1 TO 200: NEXT dum
     
	FOR n = 0 TO nmax - 1
      
	FOR m = 0 TO mmax - 1
	LINE (u(m, n), v(m, n))-(u(m + 1, n), v(m + 1, n)), scoln '''coln
	LINE (u(m, n + 1), v(m, n + 1))-(u(m + 1, n + 1), v(m + 1, n + 1)), colnn
	NEXT m
	FOR dum = 1 TO 200: NEXT dum
      
	IF vlag = 0 THEN a$ = INKEY$
	IF a$ = CHR$(27) THEN vlag = 1: EXIT SUB
	IF a$ <> "" THEN
	a$ = ""
	vlag = 1
	LOCATE 1, 60: COLOR 3: PRINT ">>> Even geduld...  "
	PLAY "o4l12d"
	END IF
       
	NEXT n
      
	FOR m = 0 TO mmax - 1
	LINE (u(m, nmax), v(m, nmax))-(u(m + 1, nmax), v(m + 1, nmax)), scoln '''coln
	NEXT m
	FOR dum = 1 TO 200: NEXT dum
     
	telscan = telscan + 1
	IF vlag = 0 AND telscan <= scan GOTO fam2
     
'        IF a$ = CHR$(27) THEN EXIT SUB
	vlag = 0: telscan = 0
	COLOR 0
	LOCATE 2, 27:  PRINT "Parameterkrommen n";
	LOCATE 1, 60:  PRINT "-> Druk een toets..."
END SUB

SUB tekenxy
	tel = tel + 1
	IF tel = 1 THEN CALL scherm: CLS
	COLOR 7
	LOCATE 1, 1
	PRINT USING "###/### :####ø rot. ##"; tel - 1; nrot; xi; nr%
	LOCATE 1, 27: COLOR 7: PRINT tit$;
	COLOR 11: PRINT "   X   ";
	COLOR 13: PRINT "Y"

''' X en Y vlak niet tonen '''
'''************************'''
IF col(4) = 7 THEN
LINE (0, 0)-(u11, v11), 0
LINE (0, 0)-(u22, v22), 0
LINE (0, 0)-(u33, v33), 0
LINE (0, 0)-(u44, v44), 0
PSET (u22, v22), 7: PSET (u44, v44), 7  ''' Toon rotatiebaan
PSET (u11, v11), 7: PSET (u33, v33), 7
LINE (0, 0)-(u1, v1), 11
LINE (0, 0)-(u2, v2), 11
LINE (0, 0)-(u3, v3), 13
LINE (0, 0)-(u4, v4), 13
u11 = u1: v11 = v1: u22 = u2: v22 = v2
u33 = u3: v33 = v3: u44 = u4: v44 = v4

ELSE
''' X en Y vlak tonen '''
'''*******************''
LINE (0, 0)-(u11, v11), 0: LINE -(u11 + u22, v11 + v22), 0
LINE -(u22, v22), 0: LINE -(0, 0), 0
LINE (0, 0)-(u33, v33), 0: LINE -(u33 + u44, v33 + v44), 0
LINE -(u44, v44), 0: LINE -(0, 0), 0
PSET (u22, v22), 7: PSET (u44, v44), 7  ''' Toon rotatiebaan
LINE (0, 0)-(u1, v1), 11: LINE -(u1 + u2, v1 + v2), 11
LINE -(u2, v2), 11: LINE -(0, 0), 11
LINE (0, 0)-(u3, v3), 13: LINE -(u3 + u4, v3 + v4), 13
LINE -(u4, v4), 13: LINE -(0, 0), 13
u11 = u1: v11 = v1: u22 = u2: v22 = v2
u33 = u3: v33 = v3: u44 = u4: v44 = v4
END IF

'''ESCAPE=STOP'''
'''***********'''
IF INKEY$ = CHR$(27) THEN xi = 360

'''Stoppen na elk beeld'''
'''********************'''
	IF ja$ = "y" THEN
	LOCATE 1, 60: COLOR 3: PRINT "-> Druk een toets..."
	IF mel = 1 THEN PLAY "l21o3c"
	SLEEP: a$ = INKEY$: IF a$ = " " THEN ja$ = ""
	END IF

END SUB

SUB tekenxyas
	IF vlagxy = 0 THEN
	COLOR 11: PRINT "   X   ";
	COLOR 13: PRINT "Y"
	END IF
	mm = max / (1.1 * fac)
	LINE (0, 0)-(u1 * mm, v1 * mm), 11
	LINE (0, 0)-(u2 * mm, v2 * mm), 3
	LINE (0, 0)-(u3 * mm, v3 * mm), 13
	LINE (0, 0)-(u4 * mm, v4 * mm), 5
END SUB

SUB tekenxyvlak
	COLOR 11: PRINT "   X   ";
	COLOR 13: PRINT "Y"
	LINE (0, 0)-(u1, v1), 11
	LINE -(u1 + u2, v1 + v2), 11
	LINE -(u2, v2), 11
	LINE -(0, 0), 11
	LINE (0, 0)-(u3, v3), 13
	LINE -(u3 + u4, v3 + v4), 13
	LINE -(u4, v4), 13
	LINE -(0, 0), 13
END SUB