MATLAB: How to plot simple histogram of multiple variables

histogram

Hello, I have the following data and my aim is to plot histograms in a single plot. Please, can you give me any hint how to start? And how to put specific colours of the histograms? Thank you!

x1 = normrnd(10,1,[1,1000]) %normal distribution
x2 = gamrnd(10,1,[1,1000]) %gamma distribution
x3 = exprnd(10,[1,1000]) %exponential distribution

Best Answer

How about the bar() function? Or the plot() function?

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
x1 = normrnd(10,1,[1,1000]) %normal distribution
x2 = gamrnd(10,1,[1,1000]) %gamma distribution
x3 = exprnd(10,[1,1000]) %exponential distribution
minValue = min([x1,x2,x3])
maxValue = max([x1,x2,x3])
numBins = 500;  % Whatever you want.
edges = linspace(minValue, maxValue, numBins);
counts1 = histcounts(x1, edges);
counts2 = histcounts(x2, edges);
counts3 = histcounts(x3, edges);
% Plot with bars.
subplot(1, 2, 1);
bar(edges(1:end-1), counts1, 'FaceColor', 'r');
hold on;
bar(edges(1:end-1), counts2, 'FaceColor', 'g');
bar(edges(1:end-1), counts3, 'FaceColor', 'b');
grid on;
xlabel('Value', 'FontSize', 20)
ylabel('Count', 'FontSize', 20)
title('Bar Chart', 'FontSize', 20)
legend('x1 histogram', 'x2 histogram', 'x3 histogram');
% Plot with lines.
subplot(1, 2, 2);
plot(edges(1:end-1), counts1, 'r-', 'LineWidth', 2);
hold on;
plot(edges(1:end-1), counts2, 'g-', 'LineWidth', 2);
plot(edges(1:end-1), counts3, 'b-', 'LineWidth', 2);
grid on;
xlabel('Value', 'FontSize', 20)
ylabel('Count', 'FontSize', 20)
title('Line Plot', 'FontSize', 20)
legend('x1 histogram', 'x2 histogram', 'x3 histogram');
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0, 0.04, 1, 0.96]);

Related Solutions

MATLAB: Axis numbers on histogram

% Demo to plot histogram and cdf of grayscale image.
% By ImageAnalyst
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
imtool close all;  % Close all imtool figures.
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 14;
% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'cameraman.tif';
fullFileName = fullfile(folder, baseFileName);
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
if ~exist(fullFileName, 'file')
  % Didn't find it there.  Check the search path for it.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, 'file')
    % Still didn't find it.  Alert user.
    errorMessage = sprintf('Error: %s does not exist.', fullFileName);
    uiwait(warndlg(errorMessage));
    return;
  end
end
grayImage = imread(fullFileName);
% Get the dimensions of the image.  numberOfColorBands should be = 1.
[rows columns numberOfColorBands] = size(grayImage);
% Display the original gray scale image.
subplot(2, 2, 1);
imshow(grayImage, []);
title('Grayscale Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off') 
% Let's compute and display the histogram.
[pixelCount grayLevels] = imhist(grayImage);
subplot(2, 2, 2); 
bar(pixelCount);
title('Histogram of image', 'FontSize', fontSize);
xlim([0 grayLevels(end)]); % Scale x axis manually.

grid on;
% Compute the CDF
cdf = cumsum(pixelCount) / numel(grayImage);
% Plot both hist and cdf on same plot
subplot(2,2,3);
bar(pixelCount);
hold on;
z = zeros(1,length(pixelCount));
plotyy(grayLevels, z, grayLevels, cdf);
title('Histogram and CDF of image', 'FontSize', fontSize);
xlim([0 grayLevels(end)]); % Scale x axis manually.
grid on;

MATLAB: Histogram

What you've put doesn't really make sense. See if this is what you want. It computes the histograms of x and y and then plots them.

clc; % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 15;
x=rand(10,1); 
y=rand(10,1);
% Plot the original x data.
subplot(2, 2, 1);
bar(x);
xlabel('Index of X', 'fontSize', fontSize);
ylabel('Value of X', 'fontSize', fontSize);
title('X as a function of Index', 'fontSize', fontSize);
% Plot the original y data.
subplot(2, 2, 2);
bar(y);
xlabel('Index of Y', 'fontSize', fontSize);
ylabel('Value of Y', 'fontSize', fontSize);
title('Y as a function of Index', 'fontSize', fontSize);
% Get the histograms.
[xCounts xValues] = hist(x)
[yCounts yValues] = hist(y)
% Plot X histogram.
subplot(2, 2, 3);
bar(xValues, xCounts);
xlabel('Value of X', 'fontSize', fontSize);
ylabel('Frequency of Occurrence for X', 'fontSize', fontSize);
grid on;
title('Histogram of X', 'fontSize', fontSize);
subplot(2, 2, 4);
bar(yValues, yCounts);
xlabel('Value of Y', 'fontSize', fontSize);
ylabel('Frequency of Occurrence forY', 'fontSize', fontSize);
grid on;
title('Histogram of Y', 'fontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'Position', get(0,'Screensize'));

Best Answer

Related Solutions

MATLAB: Axis numbers on histogram

MATLAB: Histogram

Related Question