Export Plot to SVG, PDF, HTML, PNG

import io

import numpy as np
import pandas as pd

from lets_plot import *

LetsPlot.setup_html()

df = pd.read_csv("https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/iris.csv")
print(df.shape)
df.head()

(150, 5)

	sepal_length	sepal_width	petal_length	petal_width	species
0	5.1	3.5	1.4	0.2	setosa
1	4.9	3.0	1.4	0.2	setosa
2	4.7	3.2	1.3	0.2	setosa
3	4.6	3.1	1.5	0.2	setosa
4	5.0	3.6	1.4	0.2	setosa

p = ggplot(df) + geom_point(aes("petal_length", "petal_width", color="species"), size=5) + ggsize(600, 400)
p

Export Using ggsave()

The ggsave() function is an easy way to export plot to a file in SVG, PDF, HTML or PNG formats.

Export SVG to File

fullpath_svg = ggsave(p, "plot.svg")

Load and display saved SVG.

from IPython.display import SVG

SVG(filename=fullpath_svg)

Export PDF to File

fullpath_pdf = ggsave(p, "plot.pdf")

This is what the PDF file looks like:

import base64
import urllib.request
from IPython.display import HTML

data = urllib.request.urlopen("https://github.com/JetBrains/lets-plot-docs/raw/master/source/examples/cookbook/lets-plot-images/plot.pdf").read()
b64 = base64.b64encode(data).decode("ascii")

HTML(f'<embed src="data:application/pdf;base64,{b64}" type="application/pdf" width="600" height="400">')

Export HTML to File

By default, when exporting HTML, ggsave wraps the HTML of the plot in an iframe that matches the size of the plot.

fullpath_html = ggsave(p, "plot.html")

Load and display saved HTML.

HTML(filename=fullpath_html)

Use the iframe=False option to only export the HTML of the plot, without adding an iframe.

fullpath_no_iframe = ggsave(p, "no_iframe_plot.html", iframe=False)

HTML(filename=fullpath_no_iframe)

Export to PNG File

To save plot as a PNG file use a filename that have “png” extension.

fullpath_png = ggsave(p, "plot.png")

Load and display saved PNG.

from IPython.display import Image

Image(filename=fullpath_png, width=600, height=400)

Export Plot to a File or File-Like Object

You can export figure created by ggplot() or gggrid() functions
to a vector or raster format using the following methods:

• to_svg(path)

• to_html(path, iframe)

• to_png(path, scale)

• to_pdf(path, scale)

To save plot to a file on disc, specify the file’ pathname in path.
To stream plot image to a file-like object, supply such object in the path parameter instead of a pathname.

Saving to a File

path = p.to_svg("lets-plot-images/to_svg_plot.svg")

SVG(path)

Wrighting to a Stream of In-Memory Bytes

stream = io.BytesIO()

p.to_svg(stream)

SVG(stream.getvalue())

Adjusting the Size and Aspect Ratio

Parameter scale

# default scale is 2.0
img_scale_default = ggsave(p, "scale_default_plot.png")
Image(filename=img_scale_default)

# use custom scale
img_scale_1 = ggsave(p, "scale_1_plot.png", scale=1)
Image(filename=img_scale_1)

Parameters w, h, unit and dpi

These parameters allow you to configure the export of your plot:

• w and h: Define the width and height of the output image in the specified unit.

• unit: Specifies the unit of measurement ('in', 'cm', 'mm' or 'px').

• dpi: Sets the resolution in dots per inch.

This is how they work for PNG and PDF formats:

• If w, h, unit and dpi are all specified:

  • The plot’s pixel size (default or set by ggsize()) is ignored.

  • The output size is calculated using the specified w, h, unit and dpi.

    • The plot is resized to fit the specified w x h area, which may affect the layout, tick labels and other elements.

• If only dpi is specified:

  • The plot’s pixel size (default or set by ggsize()) is converted to inches using the standard display PPI of 96.

  • The output size is then calculated based on the specified DPI.

    • The plot maintains its aspect ratio, preserving layout, tick labels and other visual elements.

    • Useful for printing - the plot will appear nearly the same size as on screen.

• If w, h are not specified:

  • The scale parameter is used to determine the output size.

    • The plot maintains its aspect ratio, preserving layout, tick labels and other visual elements.

    • Useful for generating high-resolution images suitable for publication.

For SVG format:

• If w, h and unit are specified:

  • The plot’s pixel size (default or set by ggsize()) is ignored.

  • The output size is calculated using the specified w, h and unit.

Parameters w and h

The w and h parameters override plot size, allowing to specify the output image size independently of the plot size.

img_square = ggsave(p, "square_plot.png", w=4, h=4, unit='in', dpi=100)
Image(filename=img_square)

72 dpi

img_72 = ggsave(p, "72dpi_plot.png", w=6, h=4, unit='in', dpi=72)
Image(filename=img_72, width=900, height=600)

300 dpi

img_300 = ggsave(p, "300dpi_plot.png", w=6, h=4, unit='in', dpi=300)
Image(filename=img_300, width=900, height=600)