sync with current state

apps/quadratic.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+
+import numpy as np
+import os
+import sys
+import time
+import colorsys
+
+Nx = int(sys.argv[1])
+Ny = int(sys.argv[2])
+iterations = 10
+
+class Slider:
+    def __init__(self, lo, hi, step, pos=0):
+        self.lo = lo
+        self.hi = hi
+        self.stepSize = step
+        self.pos = pos
+        self.dir = 1
+    
+    def step(self):
+        if self.pos >= self.hi:
+            self.dir = -1
+        elif self.pos <= self.lo:
+            self.dir = 1
+        
+        self.pos += self.dir * self.stepSize
+        return self.pos
+
+Sa = Slider(-10, 10, 0.1/iterations, np.random.uniform(-2, 2))
+Sb = Slider(-10, 10, 0.2/iterations, np.random.uniform(-2, 2))
+Sc = Slider(-10, 10, 0.2/iterations, np.random.uniform(-2, 2))
+Sd = Slider(-10, 10, 0.1/iterations, np.random.uniform(-2, 2))
+Se = Slider(-10, 10, 0.2/iterations, np.random.uniform(-2, 2))
+Sf = Slider(0, 6, 0.05/iterations, 0)
+
+x, y = np.meshgrid(
+    np.linspace(-4, 4, Nx),
+    np.linspace(-4, 4, Ny))
+
+color = 1.0
+
+img = np.zeros( [Ny, Nx, 3] )
+
+cr = 1.0
+cg = 0.5
+cb = 0.25
+
+step = 0
+while True:
+    a = Sa.step()
+    b = Sb.step()
+    c = Sc.step()
+    d = Sd.step()
+    e = Se.step()
+    f = Sf.step()
+
+    Sa.pos += b*0.001
+    Sb.pos += c*0.001
+    Sc.pos += d*0.001
+    Sd.pos += e*0.001
+    Se.pos += f*0.001
+    Sf.pos += a*0.001
+
+    curve = (np.abs(a*x**2 + b*x*y + c*y**2 + d*x + e*y + f) <= 1.5)*1
+
+    cr, cg, cb = colorsys.hsv_to_rgb(color, 1, 1)
+
+    img[:,:,0] = np.where(curve > 0, curve*cr*255, img[:,:,0])
+    img[:,:,1] = np.where(curve > 0, curve*cg*255, img[:,:,1])
+    img[:,:,2] = np.where(curve > 0, curve*cb*255, img[:,:,2])
+
+    step += 1
+    if step % iterations == 0:
+        out = img.reshape((Nx*Ny*3,)).astype(np.uint8)
+        os.write(1, out.tobytes())
+        time.sleep(0.01)
+
+    color = (color+0.01/iterations ) % 1
+
+
+