REM ***** MAD TEDDY'S MANDELBROT SET SERIES: REGION #23, variation C *****

REM x limits: -.2351922, -.2350578
REM y limits: .8271696, .8272704

REM ***** MY ATTEMPT TO PRODUCE SOMETHING SIMILAR TO THE "LOVE CANAL" *****

SCREEN 12

iterationlimit = 250

colour0 = 15
colour1 = 6
colour2 = 4
colour3 = 12
colour4 = 3
colour5 = 11
colour6 = 8
colour7 = 2
colour8 = 7
colour9 = 1
colour10 = 9
colour11 = 14
colour12 = 5
colour13 = 13
colour14 = 10

iterationlimitcolour = 0

ylow = .8271696
yhigh = .8272704
xlow = -.2351922
xhigh = xlow + (yhigh - ylow) * 4 / 3

FOR i = 0 TO 479
    FOR j = 0 TO 639
        x = xlow + j * (xhigh - xlow) / 639
        y = yhigh - i * (yhigh - ylow) / 479
        xc = x: yc = y
        iterations = 0
        rsquared = 0
        DO UNTIL rsquared >= 4 OR iterations > iterationlimit
            u = x * x - y * y + xc
            v = 2 * x * y + yc
            rsquared = u * u + v * v
            x = u: y = v
            iterations = iterations + 1
        LOOP
        IF rsquared >= 4 THEN
            IF iterations > 235 THEN
                colour = colour0
            ELSEIF iterations > 190 THEN
                colour = colour1
            ELSEIF iterations > 175 THEN
                colour = colour3
            ELSEIF iterations > 160 THEN
                colour = colour4
            ELSEIF iterations > 145 THEN
                colour = colour5
            ELSEIF iterations > 142 THEN
                colour = colour6
            ELSEIF iterations > 136 THEN
                colour = colour7
            ELSEIF iterations > 133 THEN
                colour = colour8
            ELSEIF iterations > 128 THEN
                colour = colour9
            ELSEIF iterations > 120 THEN
                colour = colour10
            ELSEIF iterations > 117 THEN
                colour = colour11
            ELSEIF iterations > 112 THEN
                colour = colour12
            ELSEIF iterations > 110 THEN
                colour = colour13
            ELSEIF iterations > 106 THEN
                colour = colour2
            ELSE
                colour = colour14
            END IF
        ELSE
            colour = 0
        END IF
        PSET (j, i), colour
    NEXT j
NEXT i

a$ = ""
DO: a$ = INKEY$: LOOP UNTIL a$ = CHR$(27)