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Beautiful and distinguishable line colors + colormap

version 1.4.0.0 (8.25 KB) by Jonathan C. Lansey
Plot lots of lines with very distinguishable and aesthetically pleasing colors. Works for 'N' colors

263 Downloads

Updated 16 Sep 2015

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The default Matlab default line spec and colormaps are astoundingly crude. This function creates distinguishable colors by spacing them out ~equally in *perceptive* space, not in RGB space. It is based off the research of professor Cynthia Brewer (colorbrewer!) but amazingly easy to use.
This function creates an Nx3 array of N [R B G] colors
These can be used to plot lots of lines with distinguishable and nice looking colors.
lineStyles = linspecer(N); makes N colors for you to use: lineStyles(ii,:)
colormap(linspecer); set your colormap to have easily distinguishable colors and a pleasing aesthetic
lineStyles = linspecer(N,'qualitative'); forces the colors to all be distinguishable (up to 12)
lineStyles = linspecer(N,'sequential'); forces the colors to vary along a spectrum

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Examples demonstrating the colors.

% LINE COLORS
N=6;
X = linspace(0,pi*3,1000);
Y = bsxfun(@(x,n)sin(x+2*n*pi/N), X.', 1:N);
C = linspecer(N);
axes('NextPlot','replacechildren', 'ColorOrder',C);
plot(X,Y,'linewidth',5)
ylim([-1.1 1.1]);

% SIMPLER LINE COLOR EXAMPLE
N = 6; X = linspace(0,pi*3,1000);
C = linspecer(N)
hold off;
for ii=1:N
Y = sin(X+2*ii*pi/N);
plot(X,Y,'color',C(ii,:),'linewidth',3);
hold on;
end

% COLORMAP EXAMPLE
A = rand(15);
figure; imagesc(A); % default colormap
figure; imagesc(A); colormap(linspecer); % linspecer colormap

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Credits and where the function came from:

The colors are largely taken from:
http://colorbrewer2.org and Cynthia Brewer, Mark Harrower and The Pennsylvania State University
She studied this from a phsychometric perspective and crafted the colors
beautifully.

I made choices from the many there to decide the nicest once for plotting lines in Matlab. I also made a small change to one of the colors I thought was a bit too bright. In addition some interpolation is going on for the sequential line styles. An Apache-Style Software License is included in the file.

Comments and Ratings (59)

MaRu

YH B

ZhiH

Thank you for sharing this file!

Hanghang Ma

Chen Yingqi

Very good and beautiful!

lei zhao

KAE

Useful

YOU WEIZHEN

Phuc Ho

Procat

Excellent

Fantastic!

Easy to use, thank you for this!

T Rockett

jian kang

Ray Lee

Gizem Okyay

DF

Fantastic functions, works great in MATLAB R2014a and R2014b. Thank you!

DF

Gino Delfe

BreezyWest

Fannymost

I like it,very cool

minzhen li

Jing Wen

Lying about licenses is a sneaky thing to do.

Although the Author writes that "An Apache-Style Software License is included in the file" in fact there is absolutely no APACHE license mentioned anywhere in this download. The License supplied is in fact a BSD license, the only one supported by MATLAB File Exchange.

This submission breaks the license conditions of Cynthia Brewer's ColorBrewer colorschemes, which require her APACHE license to be included:

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

Stefanos

Jamie

haiou

Note that this function breaks the original author's copyright as it does not include the copyright notice itself:

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

Yan Jiang

Very useful. It'll be even better if the colors close to yellow were darker.

VeraM

Thank you for sharing this file, very useful!

Jeff Liu

This has been my standard colormap for lines for a while. However, I regularly end up changing the color of the yellow line - it is far to light to be well recognizable on a white background.

Guojin Feng

Thanks for this great function. This makes the figure a lot better and convenient.

Thanks everyone for the nice comments, I appreciate them all.
Also thanks Stephen for the suggestions.

denny

Impressive. set it as my default

This might be of interest to the author, if they wish to improve the code of this submission:
http://www.mathworks.com/help/matlab/matlab_prog/vectorization.html

After the changes made by the author in response to my last comments, I though I would review this submission again. For the same points I made earlier:
1. The function now returns a MATLAB standard N*3 numeric colormap.
2. The default size is now 64, which still does not match the defaults of MATLAB's colormap functions.
3. There is now an H1 line (although perhaps the word 'colormap' should be included in this line?).
4. The mlint messages have been attended to (on MATLAB R2012b).
5. The examples are now complete!
6. Now calls "nargin", rather than the slow "exist".
7. "for" loops are still used to accomplish basic arithmetic. This is due to the data being stored in cell arrays. All of these "for" loops could be removed if the data was simply stored in numeric arrays.
8. Now preallocates the cell arrays before the "for" loops.
9. Unnecessary use of "varargin", when a simple second argument would suffice.
10. Improved examples.
11. Still no 'See also' line to link to related functions: "colormap", "plot", "jet", "hsv", "rgbplot",...
12. ColorBrewer data is distributed without the required Apache license:
http://www.personal.psu.edu/cab38/ColorBrewer/ColorBrewer_updates.html

Most points have been addressed, and the submission basically does what it says. However the quality of the code is poor. In particular using cell arrays to store numeric data then requires multiple local functions to perform basic numeric arithmetic. MATLAB's name derives from 'MATrix LABoratory': it is designed to perform numeric operations on numeric matrices, fast! Storing the data in cell arrays and using multiple "for" loops to achieve basic numeric functionality is poor use of MATLAB, and as a result, this submission is larger and more complicated than it needs to be to provide this functionality.

Two stars for introducing MATLAB users to better colormaps than "jet" and "hsv".

Anne Urai

beautiful, added this as the default colormap to my startup.m - no more hurting eyes. Thanks!

G W

Great reference for colors after reading this article: http://eagereyes.org/basics/rainbow-color-map

G W

G W

Andrew Tan

It's beautiful. Thank you!

What a beautiful colormap-- my new default. Thanks!

lu li

Thanks a lot!

Thanks for the most excellent feedback Stephen. I have updated the function to include almost all of your suggestions over the weekend. I hope it will be approved by Mathworks shortly.

Fix the above example: use of a colormap with multiline plots can be achieved by setting the 'ColorOrder' axes property:

N = 5;
axes('NextPlot','replacechildren', 'ColorOrder',cell2mat(linspecer(N)))
X = linspace(0,pi*3,1000);
Y = bsxfun(@(x,n)sin(x+2*n*pi/N), X.', 1:N);
plot(gca, X,Y, 'linewidth',5)

11. The M-file help section should include a 'See also ...' line, to link to similar and associated functions.
12. Distributing the colorbrewer scheme requires including a copy of the original Apache copyright license.

I have been looking for better looking, distinguishable colormaps to replace the standard ones, which at first this file seemed to offer. However this is not a drop in replacement colormap, and the M-file has multiple drawbacks, which detract from the idea:
1. Non-standard cell array output: all standard MATLAB colormaps return an Nx3 numeric matrix.
2. Non-standard default size of 255: the standard MATLAB colormaps use the current colormap size (very useful!).
3. No H1 line in the help.
4. Running mlint gives eight messages for code improvement.
5. The example does not work without the addition of extra code.
6. Calls slow functions like "exist" when "nargin" would suffice.
7. Unnecessary "for" loops could be vectorized (especially if returning the standard numeric colormap).
8. No array preallocation within the "for" loops.
9. Unnecessary use of "varargin" when a simple second input would be adequate.
10. Example shows poor use of MATLAB plot command. Compare to the code below, in half the number of lines:
N = 5;
colormap(cell2mat(linspecer(N)));
X = linspace(0,pi*3,1000);
Y = bsxfun(@(x,n)sin(x+2*n*pi/N), X.', 1:N);
plot(X,Y,'linewidth',5)

Updates

1.4.0.0

Rudimentary Colorblind support for up to 4 colors. Use the parameter "colorblind"

1.4.0.0

small change to sequential output

1.3.0.0

Adjusted the function based on the excellent suggestions of Stephen Cobeldick.

1.1.0.0

I made the colors for higher 'N' a bit darker. Also made the demo a little cleaner.

MATLAB Release Compatibility
Created with R2010b
Compatible with any release
Platform Compatibility
Windows macOS Linux