Static Image Export¶
It's possible to programmatically export figures as high quality static images while fully offline.
Using the conda package manager, you can install these dependencies in a single command:
$ conda install -c plotly plotly-orca psutil requests
Note: Even if you do not want to use conda to manage your Python dependencies, it is still useful as a cross platform tool for managing native libraries and command-line utilities (e.g. git, wget, graphviz, boost, gcc, nodejs, cairo, etc.). For this use-case, start with Miniconda (~60MB) and tell the installer to add itself to your system
PATH. Then run
conda install plotly-orca and the orca executable will be available system wide.
npm + pip¶
You can use the npm package manager to install
orca (and its
electron dependency), and then use pip to install
$ npm install -g email@example.com orca $ pip install psutil requests
Standalone Binaries + pip¶
If you are unable to install conda or npm, you can install orca as a precompiled binary for your operating system. Follow the instructions in the orca README to install orca and add it to your system
PATH. Then use pip to install
$ pip install psutil requests
Create a Figure¶
Now let's create a simple scatter plot with 100 random points of variying color and size.
import plotly.graph_objects as go import numpy as np N = 100 x = np.random.rand(N) y = np.random.rand(N) colors = np.random.rand(N) sz = np.random.rand(N) * 30 fig = go.Figure() fig.add_trace(go.Scatter( x=x, y=y, mode="markers", marker=go.scatter.Marker( size=sz, color=colors, opacity=0.6, colorscale="Viridis" ) )) fig.show()
Write Image File¶
plotly.io.write_image function is used to write an image to a file or file-like python object. You can also use the
.write_image graph object figure method.
Let's first create an output directory to store our images
import os if not os.path.exists("images"): os.mkdir("images")
If you are running this notebook live, click to open the output directory so you can examine the images as they are written.
Orca can output figures to several raster image formats including PNG, ...
Orca can also output figures in several vector formats including SVG, ...
and EPS (requires the poppler library)
Note: It is important to note that any figures containing WebGL traces (i.e. of type
parcoords) that are exported in a vector format will include encapsulated rasters, instead of vectors, for some parts of the image.
Get Image as Bytes¶
plotly.io.to_image function is used to return an image as a bytes object. You can also use the
.to_image graph object figure method.
Let convert the figure to a PNG bytes object...
img_bytes = fig.to_image(format="png")
and then display the first 20 bytes.
from IPython.display import Image Image(img_bytes)
Change Image Dimensions and Scale¶
In addition to the image format, the
write_image functions provide arguments to specify the image
height in logical pixels. They also provide a
scale parameter that can be used to increase (
scale > 1) or decrease (
scale < 1) the physical resolution of the resulting image.
img_bytes = fig.to_image(format="png", width=600, height=350, scale=2) Image(img_bytes)
In summary, to export high-quality static images from plotly.py, all you need to do is install orca, psutil, and requests and then use the
plotly.io.to_image functions (or the
.to_image graph object figure methods).
If you want to know more about how the orca integration works, or if you need to troubleshoot an issue, please check out the Orca Management section.