analistica/ex-7/plot.py

#!/usr/bin/env python

from pylab import *
import sys

def line(x, y, **args):
    '''line between two points x,y'''
    plot([x[0], y[0]], [x[1], y[1]], **args)

w = loadtxt(sys.stdin, max_rows=2)
v = array([[0, -1], [1, 0]]) @ w
cut = float(input())

n, m, d = map(int, input().split())
data  = loadtxt(sys.stdin).reshape(n + m, d)
signal, noise = data[:n].T, data[n:].T

plt.figure(figsize=(3, 3))
rcParams['font.size'] = 8
figure()
figure(figsize=(3, 3))
rcParams['font.size'] = 8
subplot(aspect='equal')
scatter(*signal, edgecolor='xkcd:charcoal',
        c='xkcd:dark yellow', label='signal')
scatter(*noise,  edgecolor='xkcd:charcoal',
        c='xkcd:pale purple', label='noise')
line(-20*w, 20*w, c='xkcd:midnight blue', label='projection')
line(w-10*v, w+10*v, c='xkcd:scarlet', label='cut')
xlabel('x')
ylabel('y')
xlim(-1.5, 8)
ylim(-1.5, 8)
legend()
tight_layout()
savefig('notes/images/7-fisher-plane.pdf')

plt.figure(figsize=(3, 3))
rcParams['font.size'] = 8
sig_proj   = np.dot(w, signal)
noise_proj = np.dot(w, noise)
hist(sig_proj,   color='xkcd:dark yellow', label='signal')
hist(noise_proj, color='xkcd:pale purple', label='noise')
axvline(cut, c='xkcd:scarlet', label='cut')
xlabel('projection line')
legend()
tight_layout()
savefig('notes/images/7-fisher-proj.pdf')