! MANDELBROT SET IN A PSEUDO 3D VIEW
!THE "CLIFFS" REPRESENT HOW FAST YOU FALL AWAY FROM THE M-SET.
!THE "CLIFF FLOOR" IS SET AT n=5,
!WHILE THE M-SET "PLATEAU" IS SET AT n=31.
!
!DEEP THOUGHT QUESTION:
!WHICH WAY WOULD YOU RATHER "CLIMB" UP TO THE PLATEAU?
!
SET MODE "graphics"
ASK PIXELS hpix,vpix
LET ratio=hpix/vpix
SET WINDOW -8*ratio,4*ratio,-2,2
SET COLOR "BLACK"
FOR j=-300 to 150
FOR k = -300 to 300
LET x = 0
LET y = 0
FOR n=1 to 30
LET x1 = x*x - y*y + j/150
LET y1 = 2*x*y + k/150
LET r2 = x1*x1 + y1*y1
IF r2>4 THEN EXIT FOR
LET x = x1
LET y = y1
NEXT n
!PLOT A PSEUDO 3D VIEW, USING n AS THE THIRD VARIABLE.
!ONLY "FRONT CLIFF" POINTS ARE PLOTTED
!unless they correspond to the M-set "butt" with cr>.25.
IF (k<=0 AND n>5) THEN PLOT 5*j/150 + 1.7*k/150,k/150 +n/60
IF (k>0 AND n=31) THEN PLOT 5*j/150 + 1.7*k/150,k/150 +n/60
IF (k>0 AND n>5 AND j>37) THEN PLOT 5*j/150 + 1.7*k/150,k/150 +n/60
NEXT k
NEXT j
END