least squares

Introduction

With GridSpec you can create any combination of panels

The code

import numpy as np
import matplotlib
import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
from matplotlib.ticker import FuncFormatter
# http://wiki.scipy.org/Cookbook/Matplotlib/LaTeX_Examples
# this is a latex constant, don't change it.
pts_per_inch = 72.27
# write "\the\textwidth" (or "\showthe\columnwidth" for a 2 collumn text)
text_width_in_pts = 246.0
# inside a figure environment in latex, the result will be on the
# dvi/pdf next to the figure. See url above.
text_width_in_inches = text_width_in_pts / pts_per_inch
# make rectangles with a nice proportion
golden_ratio = 0.618
# figure.png or figure.eps will be intentionally larger, because it is prettier
inverse_latex_scale = 2
# when compiling latex code, use
# \includegraphics[scale=(1/inverse_latex_scale)]{figure}
# we want the figure to occupy 2/3 (for example) of the text width
fig_proportion = (3.0 / 3.0)
csize = inverse_latex_scale * fig_proportion * text_width_in_inches
# always 1.0 on the first argument
fig_size = (1.0 * csize, 1.1 * csize)
# find out the fontsize of your latex text, and put it here
text_size = inverse_latex_scale * 12
tick_size = inverse_latex_scale * 8
# learn how to configure:
# http://matplotlib.sourceforge.net/users/customizing.html
params = {'backend': 'ps',
          'axes.labelsize': text_size,
          'legend.fontsize': tick_size,
          'legend.handlelength': 2.5,
          'legend.borderaxespad': 0,
          'xtick.labelsize': tick_size,
          'ytick.labelsize': tick_size,
          'font.family': 'serif',
          'font.size': text_size,
          # Times, Palatino, New Century Schoolbook,
          # Bookman, Computer Modern Roman
          'font.serif': ['Times'],
          'ps.usedistiller': 'xpdf',
          'text.usetex': True,
          'figure.figsize': fig_size,
          # include here any neede package for latex
          'text.latex.preamble': [r'\usepackage{amsmath}',
                                  ],
          }
plt.rcParams.update(params)
plt.ioff()
plt.clf()

# figsize accepts only inches.
fig = plt.figure(1, figsize=fig_size)
gs = gridspec.GridSpec(3, 2, width_ratios=[1,0.5], height_ratios=[1,0.7,0.3])
gs.update(left=0.16, right=0.86,top=0.92, bottom=0.08, hspace=0.05, wspace=0.05)

subplot a

ax0 = plt.subplot(gs[0, :])

heaviside = lambda x: 0.5 * (np.sign(x) + 1)
x = np.arange(0, 10.01, 0.01)
ax0.plot(x, heaviside(x - 2), color='purple', lw=3)
ax0.text(2.5, 1.1, r"$\longleftarrow$ heaviside")

# y ticks as a percentage
ax0.set_yticks(np.arange(-0.5, 2.0, 0.5))
def to_percent(y, position):
    # Ignore the passed in position. This has the effect of scaling the default
    # tick locations.
    s = "{:+.0f}".format(y * 100)  # str(100 * y)
    # The percent symbol needs escaping in latex
    if matplotlib.rcParams['text.usetex'] is True:
        return s + r'$\%$'
    else:
        return s + '%'
# Create the formatter using the function to_percent. This multiplies all the
# default labels by 100, making them all percentages
formatter = FuncFormatter(to_percent)
# Set the formatter
ax0.yaxis.set_major_formatter(formatter)
ax0.set_ylabel("heaviside, percentage")

# x ticks on top
ax0.axis([x.min(), x.max(), -0.5, 1.5])
ax0.xaxis.tick_top()
ax0.set_xlabel(r"x labels on top")
ax0.xaxis.set_label_position("top")

# transAxes makes position relative to axes
ax0.text(0.97, 0.97, r"\textbf{a}", transform=ax0.transAxes,
         horizontalalignment='right', verticalalignment='top')

# copy window with same x axis (y will be different)
ax0b = ax0.twinx()
ax0b.plot(x, np.tanh(x - 5), color="green", linewidth=3)
ax0b.axis([x.min(), x.max(), -1.1, 2.5])
ax0b.text(5.5, 0, r"tanh $\longrightarrow$")
ax0b.set_ylabel(r'tanh, offset label')
ax0b.yaxis.set_label_coords(1.1, 0.70)

subplot b

ax10 = plt.subplot(gs[1, 0])

x = np.arange(-5, 5, 0.01)
y = np.exp(-x)
ax10.plot(x, y, color="orange", lw=3)
ax10.set_yscale('log', basey=2)
ax10.set_yticks(2.0 ** np.arange(-7, 7, 3))
ax10.text(1.0, 1, r"$y=e^{-x}$")
ax10.set_xticks(np.arange(-5, 6, 2))
ax10.set_xticklabels(np.arange(-5, 6, 2), y=0.15)
ax10.get_yaxis().set_tick_params(direction='out')
ax10.set_ylabel("log scale base 2", labelpad=15)
ax10.text(0.97, 0.97, r"\textbf{b}", transform=ax10.transAxes,
          horizontalalignment='right', verticalalignment='top')
Text(0.97, 0.97, '\\textbf{b}')

subplot c

ax11 = plt.subplot(gs[1, 1])

x = np.arange(1.0, np.e ** 4, 0.01)
y = x ** (-0.8)
ax11.plot(x, y, color="cyan", lw=3)
ax11.text(2, 1, r"$y=x^{-0.8}$", fontsize=tick_size)
ax11.loglog(x, y, basex=np.e, basey=np.e)
xt = np.exp(np.arange(1, 4, 1))
yt = np.pi ** (np.arange(-3, 2, 1))
ax11.set_xticks(xt)
ax11.set_xticklabels(xt, y=0.15)
ax11.set_yticks(yt)


def ticks_e(y, pos):   # base e
    return r'$e^{:.0f}$'.format(np.log(y))


def ticks_pi(y, pos):  # base pi, why not?
    return r'$\pi^{%+.0f}$'%(np.log(y)/np.log(np.pi))


ax11.xaxis.set_major_formatter(FuncFormatter(ticks_e))
ax11.yaxis.set_major_formatter(FuncFormatter(ticks_pi))
ax11.yaxis.tick_right()
ax11.yaxis.set_label_position("right")
ax11.set_ylabel("right side", labelpad=10)
ax11.text(0.97, 0.97, r"\textbf{c}", transform=ax11.transAxes,
          horizontalalignment='right', verticalalignment='top')
Text(0.97, 0.97, '\\textbf{c}')

subplot d

ax20 = plt.subplot(gs[2, 0])

ax20.axis([0, 1, 0, 1])
ax20.set_xticks(np.arange(0, 1.1, 0.2))
ax20.set_xticklabels(["January", "February",
                      "March", "April",
                      "May", "June"],
                      rotation=30, horizontalalignment="right")
ax20.set_yticks([])
ax20.text(0.97, 0.97, r"\textbf{d}", transform=ax20.transAxes,
          horizontalalignment='right', verticalalignment='top')
Text(0.97, 0.97, '\\textbf{d}')

subplot e

ax21 = plt.subplot(gs[2, 1])

ax21.set_xticks([])
ax21.set_yticks([])
ax21.axis([0, 1, 0, 1])
ax21.text(0.97, 0.97, r"\textbf{e}", transform=ax21.transAxes,
          horizontalalignment='right', verticalalignment='top')
Text(0.97, 0.97, '\\textbf{e}')
%matplotlib notebook
fig.savefig("./python_figures/subplot-grid.png", dpi=300)
fig