Environment Variables

GR and GKS can be configured using a number of environment variables. The following table lists these environment variables and their effects. For information on how to set an environment variable, see the sections below.

Variable	Description
GRDIR	Path to the GR installation directory Example: /usr/local/gr/
GRLIB	Path to the GR library directory Example: /usr/local/gr/lib
GKS_FONTPATH	Path to the GKS fonts directory Example: /usr/local/gr/fonts
GKS_FILEPATH	Path to the file GKS should write its output to Example: output.png
GKS_CONID	File descriptor GKS should write its output to Example: 1
GKS_WSTYPE	Default workstation type Example: png See also: Workstation Types
GKS_ENCODING	Input encoding used for GKS functions Example: UTF-8 See also: Encoding Support
GKS_DOUBLE_BUF	Only draw when gr_updatews() is called
GKS_USE_GS_BMP	Use the gsplugin for BMP output instead of the cairoplugin See also: File Formats
GKS_USE_GS_JPG	Use the gsplugin for JPEG output instead of the cairoplugin See also: File Formats
GKS_USE_AGG_JPG	Use the aggplugin for JPEG output instead of the cairoplugin See also: File Formats
GKS_USE_GS_PNG	Use the gsplugin for PNG output instead of the cairoplugin See also: File Formats
GKS_USE_AGG_PNG	Use the aggplugin for PNG output instead of the cairoplugin See also: File Formats
GKS_USE_GS_TIF	Use the gsplugin for Tiff output instead of the cairoplugin See also: File Formats
GKS_QT_USE_CAIRO	Use the cairoplugin for rendering in the qtplugin and gksqt See also: Integrations
GKS_QT_USE_AGG	Use the aggplugin for rendering in the qtplugin and gksqt See also: Integrations
GKS_PGF_ONLY_CONTENT	Do not write a full TeX document, instead write only definitions and TikZ picture
GKS_PDF_PREVIEW_FIX	Render images using filled rectangles to workaround a problem with Apple’s Preview app, which generally uses bilinear interpolation when rendering images, resulting in blurred output, e.g. when displaying heatmaps
GKS_VIDEO_OPTS	Resolution and framerate when using the videoplugin Example: 1920x1080@60 See also: Configuring Video Output Options
GKS_GKSQT_PREVENT_RESIZE	Prevent automated resizing in gksqt
GKS_QT_VERSION	Qt version to use in the qtplugin Example: 5
GKS_NO_EXIT_HANDLER	Do not set an exit handler
GKS_DISABLE_PAGE_SUFFIX	Do not add a page suffix to the file name when writing more than once to a file which does not natively support pagination.
GKS_DEFAULT_RESAMPLE_METHOD	The default method for resampling image data in raster based workstation types. Can be nearest, linear or lanczos. Example: nearest
GR_SKIP_RUNTIME_VERSION_CHECK	Skip runtime version checks in the gr Python package

Setting Environment Variables on macOS or Linux

To set an environment variable in a shell on macOS or Linux, you can use:

export VARIABLE_NAME=value

Alternatively, for running a single command with the variable set, you can also use:

VARIABLE_NAME=value command

Setting Environment Variables on Windows

To set an environment variable in cmd.exe on Windows, you can use:

set VARIABLE_NAME=value

Setting Environment Variables in Programs

Many programming languages offer ways to set environment variables as well:

import os

os.environ["VARIABLE_NAME"] = "value"

#include <stdlib.h>

/* ... */

setenv("VARIABLE_NAME", "value", 1);

ENV["VARIABLE_NAME"] = "value"