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ColorBrewer: Attractive and Distinctive Colormaps

version 3.0 (40 KB) by

The complete palette of ColorBrewer colormaps. Simple selection by scheme name and map length.

4.86667
15 Ratings

213 Downloads

Updated

BREWERMAP provides the ColorBrewer colorschemes, especially intended for mapping and plots with attractive, distinguishable colors.

BREWERMAP is very simple to use: only the the colormap length and the colorscheme name are needed to select and define an output colormap. The colorscheme can be preselected by the user, after which only the colormap length is required to define an output colormap.

BREWERMAP can be used as a drop-in replacement for the inbuilt colormap functions and it is compatible with all MATLAB functions that require a colormap. BREWERMAP consists of just one M-file that provides all of the ColorBrewer colorschemes (no file-clutter!). Downsampling or interpolation of the nodes occurs automatically (if required). The interpolation is performed in the Lab colorspace. As an option, the colormap can be returned reversed.

### Bonus Function ###

BREWERMAP_VIEW creates an interactive figure that allows selection of the colorscheme, and that contains two colorbars showing colors of the colormap and the grayscale equivalent. It also allows adjustment of other axes' or figures' colormaps, for example:
load spine
image(X)
brewermap_view({gca})

### Examples ###

% Plot a scheme's RGB values:
rgbplot(brewermap(9,'Blues')) % standard
rgbplot(brewermap(9,'*Blues')) % reversed

% View information about a colorscheme:
[~,num,typ] = brewermap(0,'Paired')
num = 12
typ = 'Qualitative'

% Multiline plot using matrices:
N = 6;
axes('ColorOrder',brewermap(N,'Pastel2'),'NextPlot','replacechildren')
X = linspace(0,pi*3,1000);
Y = bsxfun(@(x,n)n*sin(x+2*n*pi/N), X.', 1:N);
plot(X,Y, 'linewidth',4)

% Multiline plot in a loop:
N = 6;
set(0,'DefaultAxesColorOrder',brewermap(N,'Accent'))
X = linspace(0,pi*3,1000);
Y = bsxfun(@(x,n)n*sin(x+2*n*pi/N), X.', 1:N);
for n = 1:N
plot(X(:),Y(:,n), 'linewidth',4);
hold all
end

% New colors for the COLORMAP example:
load spine
image(X)
colormap(brewermap([],'YlGnBu'))

% New colors for the SURF example:
[X,Y,Z] = peaks(30);
surfc(X,Y,Z)
colormap(brewermap([],'RdYlGn'))
axis([-3,3,-3,3,-10,5])

% New colors for the CONTOURCMAP example:
brewermap('PuOr'); % preselect the colorscheme.
load topo
load coast
figure
worldmap(topo, topolegend)
contourfm(topo, topolegend);
contourcmap('brewermap', 'Colorbar','on', 'Location','horizontal',...
'TitleString','Contour Intervals in Meters');
plotm(lat, long, 'k')

### Note ###

Note that the function BREWERMAP:
* Consists of just one convenient M-file (no .mat files or file clutter).
* No third-party file dependencies.
* Interpolates in the Lab colorspace.
* Requires just the standard ColorBrewer scheme name to select the colorscheme.
* Supports all ColorBrewer colorschemes.
* Outputs a MATLAB standard N-by-3 numeric RGB array.
* Default length is the standard MATLAB default colormap length (same length as the current colormap).
* Is compatible with all MATLAB functions that use colormaps (eg: CONTOURCMAP).
* Includes the option to reverse the colormap color sequence.
* Does not break ColorBrewer's Apache license conditions!

This product includes color specifications and designs developed by Cynthia Brewer (http://colorbrewer.org/). See the ColorBrewer website for further information about each colorscheme, colorblind suitability, licensing, and citations. Note that BREWERMAP is the only submission on MATLAB File Exchange providing ColorBrewer colorschemes without breaking the ColorBrewer license conditions!

Comments and Ratings (18)

Jeff Mackey

I thought I had a good color selection method. Nah. This blows it away!

Marko Peric

Thank you! Great work!

CKanellas

F**cing beautiful. Great job!!!

Kaiguang

Very intuitive, great preset color schemes, and easy to scale to any size data set.

E. Cheynet

COE

COE (view profile)

cheng joylin

Rong Yu

Chad Greene

Chad Greene (view profile)

This function is excellent, easy to use, and works perfectly, right out of the box. Thanks for sharing, Stephen.

M S : Thank you for your feedback. I am glad that you found my submission easy to use, as the convoluted usage of other ColorBrewer submissions on MATLAB File Exchange was one of the main motivators to write this. I intended that usage of this function should be as much like the standard colormap functions as was reasonable and feasible.

Your suggestions and observations about the unsuitability of the ColorBrewer schemes for colorblind users are very true. As you point out, the white middle color is unclear in many situations, and not just for readers with vision deficiencies.

However I did not create the ColorBrewer schemes (credit goes to Cynthia Brewer for this), nor do I make any claims about their suitability for a particular purpose, other than to say that they are "attractive, distinguishable colors". Any claims about the suitability for any particular purpose are solely those of Cynthia Brewer, for whom I am not responsible. The sole purpose of this submission is to provide the best access to the ColorBrewer colorschemes for MATLAB File Exchange users.

You might like to consider using the colormapeditor:
http://www.mathworks.com/help/matlab/ref/colormapeditor.html

Writing a colorblind-friendly maximally distant colormap generator would be quite interesting, but this is a clearly a very different task to this simple porting of Cynthia Brewer's existing colorscheme data. For a start, each of protanopia, deuteranopia, tritanopia, protanomaly, deuteranomaly, and tritanomaly would require a completely different set of permitted colors. If you are interested, contact me and we could develop this together.

M S

M S (view profile)

Pros: supports colorblind palette, which is desperately needed for matlab visualization. Easy to use.

Cons: poor for any plotting purpose; it is not designed for any visualization where there's a background color. For example, for a 'divergent', 'colorblind friendly' scheme, the middle color is always white or off white, which is obviously terrible for plots with a white background.

I wish there were a way to combine another FEX submission, distinguishable_colors--which not only arranges maximally distant colors, but takes into account background color--with colorblind friendly implementation.

Stephen Cobeldick

You are completely correct that it is possible to redistribute the ColorBrewer colorschemes: in fact this is explicitly permitted by the Apache license that they are released under.

Note though the very first license condition for redistributing ColorBrewer says that "Redistributions as source code must retain the above copyright notice, this list of conditions and the following disclaimer". So when someone redistributes it, it must be accompanied by the same Apache license*. However MATLAB File Exchange does not permit any license to be used other than the BSD license:
http://www.mathworks.com/matlabcentral/FX_transition_faq.html
"For consistency, the BSD license will be the standard for the File Exchange".

So we reach a minor impasse: to redistribute ColorBrewer requires an Apache license, to submit to MATLAB FEX requires a BSD license. Snap. I could distribute a complete version of this function under an Apache license, but not on MATLAB FEX.

Several other submissions have simply ignored ColorBrewer's Apache license, but hopefully FEX does not turn into an exchange of any licensed code that happens to take peoples fancy.

* For an example of this, scroll down to the bottom of the excel spreadsheets that are available from http://colorbrewer.org/

Nicholas

Nicholas (view profile)

Nice job, but not sure why you state you cannot redistribute the colormaps since the website suggests that you can, assuming you meet the requirements. It does, however, specifically state you cannot call the software "ColorBrewer"...

see http://www.personal.psu.edu/cab38/ColorBrewer/ColorBrewer_updates.html

Michael Chan

Michael Chan (view profile)

Beautiful work, Stephen.

John D'Errico

John D'Errico (view profile)

A very nice submission to upgrade your figures for good viewing by all viewers.

Excellent help and examples for use. I found the colorbrewer.org web site interesting too.

Updates

3.0

* Interpolate in Lab colorspace.

2.2

* Update FEX blurb.

2.2

* Include "brewermap_view.m" for interactive colormap viewing and selection.

2.1

* Improve interpolation method.

2.1

* Update screenshot image.

1.7

- Re-insert that disappearing newline at after the first paragraph. Why does this happen, MATLAB?

2.0

* Improve interpolation method.

1.5

* Change to GitHub version, complete with Apache license.

1.4

- Downloadable as toolbox

1.3

- Simplify spreadsheet downloading instructions.

1.2

- Allow case-insensitive scheme selection.
- Simplify downsampling indexing.

1.1

- Add third output: colorscheme type as a string.
- Better input checking and error messages.

MATLAB Release
MATLAB 7.11 (R2010b)

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