add old stereograph_notes script

posts/stereo/2/stereograph_notes.py

@@ -0,0 +1,93 @@
+from sympy import symbols, I, im, re, sympify, plot_parametric, sin, cos
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib import animation
+
+class LazyList:
+	def __init__(self, generator):
+		self._list = []
+		self._generator = generator
+
+	def __getitem__(self, idx):
+		final = idx
+		if isinstance(idx, slice):
+			final = idx.stop
+		while final >= len(self._list):
+			self._list.append(next(self._generator))
+		return self._list[idx]
+
+	def __repr__(self):
+		if len(self._list):
+			return repr(self._list)[:-1] + ", ...]"
+		return "[...]"
+
+t = symbols('t', real=True)
+
+e = (1 + I*t) / (1 - I*t)
+
+def generate_es():
+	ret = sympify(1)
+	while True:
+		yield ret
+		ret = (ret * e).expand().cancel().simplify()
+
+es = LazyList(generate_es())
+cs = LazyList(map(lambda x: re(x).simplify(), es))
+ss = LazyList(map(lambda x: im(x).simplify(), es))
+
+
+def make_animation(fig, frames, **kwargs):
+	#fig.tight_layout()
+	#why isn't this how the function is exposed by default
+	return lambda func: animation.FuncAnimation(fig, func, frames, init_func=lambda: None, **kwargs)
+
+def bindfig(fig):
+	def ret(**kwargs):
+		for i, j in kwargs.items():
+			if i == "figsize":
+				if j is not None:
+					fig.set_figwidth(j[0])
+					fig.set_figheight(j[1])
+				continue
+			fig.__dict__["set_" + i](j)
+		return fig
+	return ret
+
+def anim_curves(stuff=[], interval=200):
+	#zero[0,0] = 1
+	fig = plt.gcf()
+	#plt.colorbar()
+
+	#temp = plt.figure
+	#I hate doing it, but there's no other way to get the figure before it's plotted
+	plt.figure = bindfig(fig)
+
+	@make_animation(fig, len(stuff), interval=interval)
+	def ret(fr):
+		fig.clf()
+		idx1, idx2 = stuff[fr]
+
+		plot_parametric(idx1, idx2, xlim=(-2,2), ylim=(-2,2), backend='matplotlib')
+		#plt.title(f"$x = c_{{{idx1}}}c_{{{idx2}}}; y = c_{{{idx1}}}s_{{{idx2}}}$")
+		plt.tight_layout()
+
+	return ret
+
+plot_roses = lambda roses: anim_curves([(cs[i]*cs[j], cs[i]*ss[j]) for i,j in roses], interval=500)
+#plot_roses([(1,1),(1,2),(2,1),(3,1),(3,2),(2,3),(1,3),(1,4),(3,4),(4,3),(4,1)]).save()
+
+def archimedes_frames():
+	writer = animation.writers['ffmpeg'](fps=15, metadata={'artist': 'Me'})
+	#fig = plt.gcf()
+
+	for i in range(10):
+	#for i in range(1):
+		i += 1
+		p = plot_parametric(t*cos(t), t*sin(t), xlim=(-4,4), ylim=(-4,4), label="Archimedean Spiral", show=False)
+		p.save(f"frame{i}.png")
+		p.extend( 
+			plot_parametric(2*i*t*cs[i], 2*i*t*ss[i], line_color="black", label=f"$R_{{{i}}}(t) = {2*i}t$", 
+			show=False) 
+		)
+		p.legend = True
+		p.save(f"frame%02d.png" % i)