Matplotlib

Matplotlib’s PostScript backend writes any figure as EPS: call savefig with a .eps file name or format="eps". The figure stays vector (lines, text, markers); images such as imshow output are embedded as bitmaps. Many journals and the latex + dvips route still ask for EPS figures.

PostScript has no transparency: artists with alpha < 1 are drawn opaque and Matplotlib prints a warning. Use PDF or SVG output when you need transparency.

Installation#

pip install matplotlib

Basic usage: save a chart as EPS#

import matplotlib
matplotlib.use("Agg")  # no window needed
import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 2 * np.pi, 200)
fig, ax = plt.subplots(figsize=(4, 3))  # inches
ax.plot(x, np.sin(x), label="sin")
ax.plot(x, np.cos(x), label="cos")
ax.set_xlabel("x")
ax.legend()

fig.savefig("plot.eps", bbox_inches="tight")  # crop white space

How to embed fonts as TrueType instead of Type 3#

By default text uses Type 3 fonts, which some publishers reject. Type 42 embeds the TrueType font:

import matplotlib.pyplot as plt

plt.rcParams["ps.fonttype"] = 42
fig.savefig("plot.eps")

How to use LaTeX for the text in an EPS figure#

plt.rcParams.update({
    "text.usetex": True,         # needs a TeX installation
    "font.family": "serif",
})
ax.set_title(r"$\int_0^\pi \sin x \, dx = 2$")
fig.savefig("plot.eps")

How to get an exact bounding box#

ps.usedistiller post-processes the file with Ghostscript (or Xpdf), which also recomputes a tight bounding box:

plt.rcParams["ps.usedistiller"] = "ghostscript"
fig.savefig("plot.eps")

How to save as PostScript with a paper size#

fig.savefig("plot.ps", papertype="a4", orientation="portrait")

.ps output is a full page; .eps is cropped to the figure.

Tips#

• Replace transparency with solid colors before saving EPS, for example a light gray instead of black with alpha=0.2.
• Large scatter plots make huge EPS files. Pass rasterized=True to the artist (ax.scatter(..., rasterized=True)) and set dpi=300 in savefig to embed that layer as a bitmap.