gramm data visualization toolbox

gramm is a powerful and full-featured plotting and visualization toolbox similar to ggplot2 or seaborn
Updated 10 Jul 2024

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Gramm is a MATLAB toolbox that enables the rapid creation of complex, publication-quality figures. Its design philosophy focuses on a declarative approach, where users specify the desired end result, as opposed to the traditional imperative method involving for loops, if/else statements, etc.

The MATLAB implementation of gramm is inspired by the "grammar of graphics" principles (Wilkinson 1999) and the ggplot2 library for R by Hadley Wickham. As a reference to this inspiration, gramm stands for GRAMmar of graphics for MATLAB. A similar library called Seaborn also exists for Python.

Gramm has been used in many publications from varied fields and is particularily suited for neuroscience, from human movement psychophysics (Morel et al. 2017), to electrophysiology (Morel et al. 2016; Ferrea et al. 2017), human functional imaging (Wan et al. 2017) and animal training (Berger et al. 2017).

Demo live scripts

Typical use cases are described in these live scripts. We recommend opening the live scripts in MATLAB to benefit from interactive elements. A simplified workflow is presented below this table.

To run the files in Matlab online, you will need to add the gramm folder to your path (select the gramm folder in the files panel on the left, right click>Add to Path>Selected Folder(s)).

  • Getting Started:

👀 PreviewOpen in MATLAB Online

  • Explore grouped data:

👀 PreviewOpen in MATLAB Online

  • Explore X/Y data:

👀 PreviewOpen in MATLAB Online

  • Explore Time Series data:

👀 PreviewOpen in MATLAB Online

  • Advanced examples:

👀 PreviewOpen in MATLAB Online


The typical workflow to generate this figure with only 7 lines of code is detailed in the "Getting Started" live script.. The figure uses data from the carbig dataset and represents the evolution of fuel economy of new cars with time, depending on the number of cylinders indicated by color, and regions of origin separated across subplot columns.

GettingStarted example

Here are the main steps to generate this figure:

  1. Provide gramm with the relevant data for the figure: X and Y variables, but also the variables that will determine color, subplot rows/columns, etc.
load example_data.mat %Load example dataset about cars

% Create a gramm object g, provide x (year of production) and y (fuel economy) data,
% color grouping data (number of cylinders) and select a subset of the data (even numbers of cylinders)
% Subdivide the data in subplots horizontally by region of origin
  1. Add graphical layers to your figure: raw data layers (directly plot data as points, lines...) or statistical layers (fits, histograms, densities, summaries with confidence intervals...). One instruction is enough to add each layer, and all layers offer many customization options.
 % Plot raw data as points with a small horizontal offset between groups
% Plot linear fits of the data
  1. Optionally configure legends, title and adjust the look the figure (colors, axes, etc.)
% Set appropriate names for legends
g.set_names('column','Origin', 'x','Year of production', 'y','Fuel economy (MPG)',...
    'color','# Cylinders');
%Set figure title
g.set_title('Fuel economy of new cars between 1970 and 1982');
  1. Draw the figure, gramm takes care of all the annoying parts: no need to loop over colors or subplots, colors and legends are generated automatically, axes limits are taken care of, etc.

About gramm

Installing gramm

We recommend installing gramm directly through MATLAB's Add-ons explorer. Search for "gramm" and click Add!

You can also install gramm manually by downloading the latest .mltbx file or by adding the gramm folder from the repository to your path.


Once the toolbox is installed, type doc in the MATLAB command window and you will see gramm in the "Supplemental Software" section at the bottom of the left navigation bar. From there you will have access to several live script demos and a cheat sheet with all commands in a compact format.

Citing gramm

Gramm has been published in the Journal of Open Source Software. If you use gramm plots in a publication you can thus cite it using the following:

Morel, (2018). Gramm: grammar of graphics plotting in Matlab. Journal of Open Source Software, 3(23), 568,


Recent versions of gramm (3.0 and above) target MATLAB above R2018b. Older releases work in older MATLAB versions. The statistics toolbox is required for some methods: stat_glm(), some stat_summary() methods, stat_density(). The curve fitting toolbox or the statistics toolbox is required for stat_fit().

Main Features

  • Accepts X, Y, Z and grouping data in varied types and shapes (arrays, matrices, cells)

  • Multiple ways of separating groups of data:

    • Colors, lightness, point markers, line styles, and point/line size ('color', 'lightness', 'marker', 'linestyle', 'size')
    • Subplots by row and/or columns, or wrapping columns (facet_grid() and facet_wrap()). Multiple options for consistent axis limits across facets, rows, columns, etc. (using 'scale' and 'space')
    • Separate figures (fig())
  • Multiple ways of directly plotting the data:

    • scatter plots (geom_point()) and jittered scatter plot (geom_jitter())
    • lines (geom_line())
    • pre-computed confidence intervals (geom_interval())
    • bars plots (geom_bar())
    • raster plots (geom_raster())
    • labels (geom_label())
    • point counts (geom_count())
    • swarm / beeswarm plots (geom_swarm())
    • text labels (geom_label())
  • Multiple statistical visualizations on the data:

    • y data summarized by x values (uniques or binned) with confidence intervals (stat_summary())
    • histograms and density plots of x values (stat_bin() and stat_density())
    • box and whisker plots (stat_boxplot())
    • violin plots (stat_violin())
    • quantile-quantile plots (stat_qq()) of x data distribution against theoretical distribution or y data distribution.
    • Smoothed data (stat_smooth())
    • 2D binning (stat_bin2d())
    • GLM fits (stat_glm(), requires statistics toolbox)
    • Custom fits with user-provided anonymous function (stat_fit())
    • Ellipses of confidence (stat_ellipse())
  • Easy export in multiple formats with a convenient export() method that can be called after draw() and maintains correct dimensions/aspect ratio.

  • All visualizations have plenty of options accessible through arguments, from computational to esthetic ones.

  • Representation of groupings can be fully customized (colormaps, ordering)

  • Multiple gramm plots can be combined in the same figure by creating a matrix of gramm objects and calling the draw() method on the whole matrix.

  • MATLABs axes properties are modifiable through the method axe_property()

  • Non-data graphical elements can be added such as reference lines or polygons (geom_abline(), geom_vline(),geom_hline(),geom_polygon())

  • For advanced customization, handles of all graphic elements and computation results are easily available after the draw() through the results structure of the gramm object


All these examples are from the advanced examples live scripts

Superimposition of gramm objects on the same axes

Custom layouts

Custom layouts

Grid and scaling options

facet_grid() options

Colormap and legend options

facet_grid() options


gramm was inspired and/or used code from:

Cite As

Morel, Pierre. “Gramm: Grammar of Graphics Plotting in Matlab.” The Journal of Open Source Software, vol. 3, no. 23, The Open Journal, Mar. 2018, p. 568, doi:10.21105/joss.00568.

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MATLAB Release Compatibility
Created with R2023b
Compatible with R2018a and later releases
Platform Compatibility
Windows macOS Linux

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Version Published Release Notes

See release notes for this release on GitHub:


See release notes for this release on GitHub:


See release notes for this release on GitHub:


Switching to new github integration


Added full tab auto-complete for arguments and options with functionSignatures.json

Updated description

- Added JOSS paper and DOI information
- Fixed set_datetick() behavior

Preparation for JOSS submission

Added set_layout_options() allowing to fully customize figure layout in gramm

Corrected bug in geom_bar() when used with the 'stacked' option

- Overhaul of legend and colormap support
- Allows for non LCH luminance/color colormaps
- Added new built-in colormaps
- Added new legend options

Added toggles for row/column labels, improved handling of empty subsets

- Added more customization options to geom_bar
- Fixed automatic continuous colors
- Various fixes

Gramm now merges color and marker/size/linestyle legend if they are the same

- Added continuous color support to 3D lines and points
- Added colorbrewer license file

- Possibility to set ‘CLim’ in set_continuous_color() in order to force color limits.
- Fixed bug on continuous colors when a unique value was provided
- Documentation updates

Added geom_polygon() method to add custom polygons on plots

- Improved graphic fixes for old matlab versions
- Updated geom_abline() , geom_vline(), geom_hline() functions
- Bug fixes
- Added missing documentation

- Added export() method
- Added 'interpreter' to set_text_options()

Added coord_flip(), which can be used to generate horizontal box plots, violin plots, error bars, etc.

- Added the possibility to provide a custom function to stat_summary()
- Removed unnecessary computation when stat_smooth() was used with default options (2x speedup!)

- stat_smooth() now provides more smoothing algorithms, better documentation and more conservative CI estimates
- Enhancements and better documentation for set_order_options()
- Bug fixes in edge cases (empty elements in cells, etc.)

- Added fig() function to separate data across figures
- Improved copy() behavior

Corrected bug in stat_summary() polar interpolation when x data didn't start at zero radians. Added safety checks.

- Corrected absence of y ticks if single facet when using facet_wrap()
- Corrected behavior of stat_cornerhist() when ‘DataAspectRatio’ is set to [1 1 1] using axe_property()

Added 'alpha' option to geom_point(), geom_jitter() and geom_line()

- Added geom_label() to plot text
- Added additional examples
- Modified continuous color legend

- Added set_stat_options() to specify alpha level and N bootstrap samples in all stat_ functions
- Added 'viridis' colormap
- Default confidence interval in stat_summary is now corrected for normal distributions with small N
- Other improvements

Added customization options for text, lines and points:
- Added set_line_options(): style, size
- Added set_point_options(): markers, size
- Added set_text_options(): font, sizes
- Corrected bug with iscategorical() on old matlab versions

- Added corner histogram of x-y difference stat_cornerhist()
- Improved speed on large datasets with many non-unique x values

- Added notch option to stat_boxplot()
- Corrected bug in stat_ellipse() for 2014a and earlier versions

- Added stat_violin() to create violin plots
- BETA of stat_cornerhist to plot an histogram of the x-y difference in an inset axis (has an intermittent sizing bug).

Added functionality to edit legend axes

- Corrected rare error on y limit computation
- Simplified code in draw()
- Changed thumbnail

Corrected error with geom_line() and 3D data

- Represent user-provided confidence intervals with geom_interval()
- Improved dodging: now takes in account the number of colors per x values
- Dodging supported in additional geom_ methods
- Improved geom_bar() stacking

- Corrected errorbar thickness
- Improved update() behavior

- Added set_parent() method
- Improved dodging for categorical x
- Improved update() behavior

Updated description

- Full refactor from a single file to a @gramm class folder
- examples.m is now a proper how-to and can be published
- With the update() method, use different groupings for different layers
- Support for categorical variables in faceting

Corrected stat_summary() to prevent erroneous line/area interruptions

- Added 'space' option to facet_grid()
- Updated examples and Readme

- Improved legend layout
- Harmonized 'width' and 'dodge' arguments
- Improved stat_summary() behavior for missing elements
- Optimizations

- Changed Picture

- ‘z’ input data in gramm() creates 3D plots when using geom_point() or geom_line()
- Corrected bugs in box plot and corrected whisker length
- Added possibility to superimpose gramm plots
- Corrected support for categorical data

Added possibility to set a global title with set_title()

Description correction

Added simpler way to set ordering with set_order_options()

- Added set_order_options()
- Added ‘map’ option to set_color_options()
- Customization functions can be called on arrays of gramm objects
- Bug fixes

Added box and whiskers plots, Quantile-Quantile plots
Other modifications and corrections (see Github: )

Added cheat sheet, added geom_funline(), added 'dodge' option to stat_summary()

- Results from stat_ plots are now returned in the results member structure.
- Corrected bugs with pre 2014b versions

Changing manually the limits (using pan or zoom) of a facet in a gramm generated figure will now automatically change the scale of the other facets according to the ‘scale’ facet preferences

- Added stat_fit() for custom fits (requires curve fitting toolbox)
- Added more generic ‘fill’ options to stat_bin()
- stat_bin() and stat_density() now behave when using polar plots
- Added documentation
- Reduced clutter
- Added examples

Plenty of new features (separation by lightness, confidence ellipses, color options, geom_hline, geom_vline)

Bug corrrection

Enhancements and bug fixes for continuous colors, which can now be forced and customized using set_continuous_color()

Added ‘edges’ option for custom bins to stat_bin2d() and stat_bin()
Added ‘bar_color’ and ‘bar_spacing’ options, ‘overlaid_bar’ geom to stat_bin()
Now possible to set multiple properties at once in axe_property()
Corrected behavior of facet scaling

Greatly improved geom_raster() speed when used with option 'geom','line'

Additional usage examples

Corrected set_datetick() issue, corrected initialization of faceting variables

To view or report issues in this GitHub add-on, visit the GitHub Repository.
To view or report issues in this GitHub add-on, visit the GitHub Repository.