Add matplotlib pgf example

Author: maxnoe

matplotlib_pgf/Makefile

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+# * We use the modern lualatex engine which allows choosing opentype system fonts
+# * All LaTeX output will go to the `build` directory which is gitignored
+# * We stop at the first error
+# * We don't allow LaTeX to prompt us, Makefiles should be noninteractive
+texopts = --lualatex \
+	  --output-directory=build \
+	  --halt-on-error \
+	  --interaction=nonstopmode
+
+
+all: build/proceeding.pdf
+
+
+# latexmk is an awesome tool, that automagically
+# determines, which files have changed and which 
+# programs need to be run on the inputfiles
+# latexmk does its own dependency management, so we FORCE it to always run
+# by using this pseudo target
+build/proceeding.pdf: FORCE build/plot.pdf
+	latexmk $(texopts) proceeding.tex
+
+build/plot.pdf: matplotlibrc matplotlib_header.tex settings.tex plot.py | build
+	# matplotlib runs latex in /tmp, so we need to add the 
+	# current working directory to the TEXINPUTS, so LaTeX can find 
+	# our header file
+	TEXINPUTS=$(shell pwd): python plot.py
+
+build:
+	mkdir -p build
+
+clean:
+	rm -rf build
+
+FORCE:
+
+.PHONY: clean all FORCE

matplotlib_pgf/README.md

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+# Using the system LaTeX installation with matplotlib
+
+We use the pgf backend of matplotlib to create publication quality pdf
+plots.
+
+The example uses the modern `lualatex` engine, so you'll need a relatively 
+recent `TeXLive`, everything >= 2016 should work.
+
+The method itself also supports `pdflatex` and `xelatex`.
+
+For more information see:
+
+* https://matplotlib.org/users/pgf.html
+* https://matplotlib.org/users/customizing.html

matplotlib_pgf/before.pdf

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+% In this file, we only use the packages that
+% have an influence on our plot appearance, like math packages
+% and font settings
+\usepackage{fontspec}
+\usepackage{polyglossia}
+
+\usepackage{amsmath}
+\usepackage{mathtools}
+
+\usepackage[per-mode=reciprocal]{siunitx}
+
+\usepackage[
+  math-style=ISO,
+  bold-style=ISO,
+  nabla=upright,
+  partial=upright,
+  mathrm=sym,
+]{unicode-math}
+
+\input{settings.tex}

matplotlib_pgf/matplotlib_header.tex

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+backend:            pgf  # use system latex and the pgf graphics package
+figure.figsize:     5.781, 3.573  # size in inch
+
+text.usetex:        true
+pgf.rcfonts:        false  # set fonts in matplotlib_header.tex, not here
+pgf.texsystem:      lualatex # also supported: pdflatex, xelatex
+pgf.preamble:       \input{matplotlib_header.tex} # just input the actual header
+
+font.size:          11
+legend.fontsize:    11
+xtick.labelsize:    9
+ytick.labelsize:    9
+font.family:        serif

matplotlib_pgf/matplotlibrc

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+import matplotlib.pyplot as plt
+import numpy as np
+
+
+formula = (
+    r'$\displaystyle '
+    r'N = \int_{E_\text{min}}^{E_\text{max}} '
+    r'\int_0^A'
+    r'\int_{t_\text{min}}^{t_\text{max}} '
+    r'Φ_0 \left(\frac{E}{\SI{1}{\GeV}}\right)^{\!\!-γ}'
+    r' \, \symup{d}A \, \symup{d}t \, \symup{d}E'
+    r'$'
+)
+
+
+def power_law_spectrum(energy, normalisation, spectral_index):
+    return normalisation * energy**(-spectral_index)
+
+
+bin_edges = np.logspace(2, 5, 15)
+bin_centers = 0.5 * (bin_edges[:-1] + bin_edges[1:])
+
+y = power_law_spectrum(bin_centers, 1e-5, 2.5)
+relative_error = np.random.normal(1, 0.2, size=len(y))
+y_with_err = relative_error * y
+
+plt.errorbar(
+    np.log10(bin_centers),
+    y_with_err,
+    xerr=[
+        np.log10(bin_centers) - np.log10(bin_edges[:-1]),
+        np.log10(bin_edges[1:]) - np.log10(bin_centers)
+    ],
+    yerr=0.5 * y_with_err,
+    linestyle='',
+)
+
+plt.xlabel(r'$\log_{10}\bigl(E \mathbin{/} \si{\giga\electronvolt}\bigr)$')
+plt.ylabel(
+    r'$\Phi_0'
+    r'\mathbin{/}'
+    r'\bigl(\si{\per\GeV\per\second\per\steradian\per\meter\squared}\bigr)$'
+)
+
+plt.text(0.1, 0.1, formula, transform=plt.gca().transAxes)
+plt.yscale('log')
+
+plt.tight_layout(pad=0)
+plt.savefig('build/plot.pdf')

matplotlib_pgf/plot.py

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+import matplotlib.pyplot as plt
+import numpy as np
+
+
+formula = (
+    r'$'
+    r'N = \int_{E_\mathrm{min}}^{E_\mathrm{max}} '
+    r'\int_0^A'
+    r'\int_{t_\mathrm{min}}^{t_\mathrm{max}} '
+    r'\Phi_0 \left(\frac{E}{1\,\mathrm{GeV}}\right)^{\!\!-\gamma}'
+    r' \, \mathrm{d}A \, \mathrm{d}t \, \mathrm{d}E'
+    r'$'
+)
+
+
+def power_law_spectrum(energy, normalisation, spectral_index):
+    return normalisation * energy**(-spectral_index)
+
+
+bin_edges = np.logspace(2, 5, 15)
+bin_centers = 0.5 * (bin_edges[:-1] + bin_edges[1:])
+
+y = power_law_spectrum(bin_centers, 1e-5, 2.5)
+relative_error = np.random.normal(1, 0.2, size=len(y))
+y_with_err = relative_error * y
+
+plt.errorbar(
+    np.log10(bin_centers),
+    y_with_err,
+    xerr=[
+        np.log10(bin_centers) - np.log10(bin_edges[:-1]),
+        np.log10(bin_edges[1:]) - np.log10(bin_centers)
+    ],
+    yerr=0.5 * y_with_err,
+    linestyle='',
+)
+
+plt.xlabel(r'$\log_{10}(E \,\,/ \,\, \mathrm{GeV})$')
+plt.ylabel(
+    r'$\Phi_0'
+    r'\,\,/\,\,'
+    r'(\mathrm{GeV}^{-1} \, \mathrm{s}^{-1} \, \mathrm{sr}^{-1} \mathrm{m}^{-2})$'
+)
+
+plt.text(0.1, 0.1, formula, transform=plt.gca().transAxes)
+plt.yscale('log')
+
+plt.tight_layout(pad=0)
+plt.savefig('build/before.pdf')

matplotlib_pgf/plot_before.py

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+\documentclass{scrartcl}
+
+\usepackage{fontspec}
+
+\usepackage{polyglossia}
+\setmainlanguage{english}
+
+\usepackage{amsmath}
+\usepackage{mathtools}
+
+\usepackage[per-mode=fraction]{siunitx}
+
+\usepackage[
+  math-style=ISO,
+  bold-style=ISO,
+  nabla=upright,
+  partial=upright,
+]{unicode-math}
+
+\usepackage{blindtext}
+\usepackage{graphicx}
+
+\input{settings.tex}
+\recalctypearea % after changing the font, recalculate margin sizes
+
+
+\begin{document}
+  % get LaTeX to print the textwidth to use it as plot width
+  \section{Get the textwidth}
+  Textwidth: \the\textwidth \\
+  $\SI{1}{in} = \SI{72.27}{pt}$ 
+
+  \section{Awesome plot}
+  
+  \blindtext
+
+  \begin{figure}[htbp]
+    \centering
+    % note we don't use any of width= or scale=, the plot as the correct size
+    \includegraphics{build/plot.pdf}
+    \caption{%
+      Plot with same font family and size as main document
+    }\label{fig:plot}
+  \end{figure}
+
+  \blindtext
+
+\end{document}

matplotlib_pgf/proceeding.tex

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+\setromanfont{Libertinus Serif}
+\setmathfont{Libertinus Math}