MATLAB: Change colormap of histogram2

colormaphistogramhistogram2

Hi,

I was looking for a way to change the colormap for histogram2 from parula to something else. Couldn't find it.

x = randn(5000);
y = randn(5000);
h = histogram2(test1, test2, 'DisplayStyle','tile');

again: I couldn't find any handle or option to change the colormap.I'd appreciate a hint.

kind regards

Arnold

Best Answer

Use the colormap function. First let's make the histogram2 plot.

x = randn(5000);
y = randn(5000);
h = histogram2(x, y, 'DisplayStyle','tile');

Next, I'll enable the colorbar (so we can see the color scale.)

colorbar

Finally I'll change the colormap. I'll use jet but you can use one of the ones on the colormap documentation page or one of your own design.

colormap(jet)

Related Solutions

MATLAB: How to show bin counts’ percentage values in Histogram2 tile plot

I have solved it writing a function manually add text to each rectangle.

Here is the function:

function hHist = normalized_histogram2(hAxes,xVals,yVals,xEdges,yEdges)
% Creates a 2D Histogram plot of data counts percentage in each bins.
% Add percentage values as text inside each bin. 
% Font size and font weight can be changed manually inside the code or
% added to function inputs. 
% NOTE: If text does not fit the rectangles, change font size or maximize
% figure plot. 
%% inputs: 
% hAxes - axis handle object for the plot
% xVals - a double vector of x values
% yVals - a double vector of y values
% NOTE: xVals and yVals must be the same length
% xEdges - a double vector of x bins
% yEdges - a double vector of y bins
%% outputs:
% hHist - histogram object handle
hist_Counts = histcounts2(xVals,yVals,xEdges,yEdges);
hist_Counts_normalized = (hist_Counts / sum(hist_Counts,'all'))*100;
hHist = histogram2(hAxes,'XBinEdges',xEdges,'YBinEdges',yEdges,'DisplayStyle','tile','BinCounts',hist_Counts_normalized);
colorbar;
xBinCenters = hHist.XBinEdges - [0,diff(hHist.XBinEdges)/2];
yBinCenters = hHist.YBinEdges - [0,diff(hHist.YBinEdges)/2];
for i = 2:numel(xBinCenters)
    
    for j = 2:numel(yBinCenters)
        x_loc = xBinCenters(i);
        y_loc = yBinCenters(j);
        if ~(round(hHist.Values(i-1,j-1),2) == 0)
            text(hAxes,x_loc,y_loc,[num2str(round(hHist.Values(i-1,j-1),2)),'%'],'Color',[0 0 0],'FontSize',10,'FontWeight','bold');
        else
            continue
        end
        
    end
end

Here is the demo:

%% Data Creation:
xVals = randn(1,10000);
yVals = randn(1,1000)*5;
xEdges = min(xVals):1:max(xVals);
yEdges = min(yVals):5:max(yVals);
%% Demo:
hFig = figure;
hAxes = axes(hFig);
normalized_histogram2(hAxes,xVals,yVals,xEdges,yEdges);
% make plot look beautiful:
xlabel('X Data');
ylabel('Y Data');
title('Normalized Histogram 2');
hFig.WindowState = 'maximized';

It will look like below:

MATLAB: Normalization of colorbar showing bincounts of binscatter

I would use histcounts2() to determine the density within each bin. Then you can normalize those data and send it into histogram2(). See comments within the code below for details.

x=rand(1,10000);
y=rand(1,10000);
% compute bin counts
[binCounts, xbin, ybin] = histcounts2(x,y,[100,100]); 
% Normalize bin counts to 0:1
binCountsNorm = (binCounts - min(binCounts(:))) ./ range(binCounts(:)); 
% Plot the results *
histogram2('XBinEdges',xbin,'YBinEdges',ybin,'BinCounts',binCountsNorm, ...
    'DisplayStyle','tile','ShowEmptyBins','on') % or you may what "off"
% Add color bar and make sure the color ranges from 0:1
colorbar()
caxis([0,1])

*The histogram2() options require r2016b or later:

Best Answer

Related Solutions

MATLAB: How to show bin counts’ percentage values in Histogram2 tile plot

MATLAB: Normalization of colorbar showing bincounts of binscatter

Related Question