how to display points from very light red to dark red?

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davit petraasya 2016-3-11

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https://ww2.mathworks.cn/matlabcentral/answers/272874-how-to-display-points-from-very-light-red-to-dark-red

评论： davit petraasya 2016-3-15

Hi I have 100 points.(100 x and 100 y). I want to plot the points from very light red to very dark red. 1-point very light red,sequence gets darker and darker, and final 100-point totally dark red. Is it possible to do it?

Thanks!

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Answer 1

Julie 2016-3-11

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编辑：Julie 2016-3-11

在 MATLAB Online 中打开

See Below code

c = linspace(1,10,length(x));
G=linspace(.95,0,length(x)); % Increase the .95 for lighter red at beginning, increase the 0 for lighter red at the end 
map=[ones(length(x),1),G',G'];
colormap(map)
scatter(x,y,[],c)

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Image Analyst 2016-3-11

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Or

scatter(x, y, [], c, 'filled'); % Make solid discs instead of hollow discs.

davit petraasya 2016-3-15

Thanks Julie, it helped!

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Answer 2

Chad Greene 2016-3-11

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https://ww2.mathworks.cn/matlabcentral/answers/272874-how-to-display-points-from-very-light-red-to-dark-red#answer_213264

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I recommend brewermap because Jan Brewer's colormaps have been thoughtfully designed and have a nearly linear lightness gradient. That is, the changes in lightness of Jan Brewer's color maps occur at approximately the same rate as the changes in the data they represent.

Here's an example using scatter. Start with Matlab's default colormap:

scatter(1:100,1:100,50,1:100,'filled','markeredgecolor','k')

Then change the colormap:

colormap(brewermap(256,'reds'))