graphic1.py

graphic1.py

import numpy as np
from PIL import Image

#-------------------------------------------------------------------
#
#  a few helper functions
#
def create_XY(X, Y, x0, x1, y0, y1, endpoint=False, dtype=np.float64):
    I = np.indices((Y,X)).astype(np.float64)
    fy = (y1 - y0) / (Y - 1) if endpoint else (y1 - y0) / Y
    fx = (x1 - x0) / (X - 1) if endpoint else (x1 - x0) / X
    I[0], I[1] = x0 + fx*I[1], y0 + fy*I[0]
    return I.astype(dtype)
    
def colorize(R, bins, rgb0, rgb1):
    bin_widths = bins[1:] - bins[:-1]
    D = np.digitize(R, bins[1:-1])
    C0 = np.take(rgb0, D, axis=0)
    C1 = np.take(rgb1, D, axis=0)
    F = (R - np.take(bins, D))/np.take(bin_widths, D)
    F = np.repeat(F, 3)
    F.shape = C0.shape
    C = (1-F)*C0 + F*C1
    return C

def normalize(x, floor = -1e+300, ceil = +1e+300, nan_replace = 0.0):
    x = np.where(np.isnan(x), nan_replace, x)
    x = np.maximum(x, floor)
    x = np.minimum(x, ceil)
    xmin, xmax = np.min(x), np.max(x)
    return (x - xmin) / (xmax - xmin)

def save_rgb(R, path):
    R = np.round(R).astype(np.uint8)
    image = Image.fromarray(R, mode='RGB')
    image.save(path)        
        
#-------------------------------------------------------------------
#
#  the calculation
#
def smod(a, b):
    return np.fmod(a.astype(np.int64), 1 + np.abs(b.astype(np.int64)))
    
W, H = 800, 800
range = 10.24
x, y = create_XY(W, H, -range, range, -range, range)
r1 = np.tan(x)
r2 = np.tan(y)
r3 = smod(r1, r2)
r4 = smod(y, r1)
r5 = np.sin(r3 + np.sin(r4 * np.exp(r2)) + r4)
r6 = normalize(r5)
#-----------------------------------------------
color_stops = np.array([-0.001, 1.001])
rgb_from = np.array([[0, 0, 0]])
rgb_to = np.array([[190, 178, 236]])
r7 = colorize(r6, color_stops, rgb_from, rgb_to)
#-----------------------------------------------
save_rgb(r7, 'result.jpg' )

result.jpg