Lab 6, Histogram (Due Apr. 11, 11:59 PM, 2015)

Shanshan Zhang, tuf14438@temple.edu Learn to plot a histogram according to the definition in the textbook.

Data
Histogram with bin width 10
Histogram with bin width 30
Histogram with bin width 50
Assignments

Data

Draw histograms for a sample with discrete numbers: [12, 15, 34, 24, 35, 67, 89, 13, 45, 36, 89, 46, 97, 34, 56, 78, 65, 83, 59, 74]

X = [12, 15, 34, 24, 35, 67, 89, 13, 45, 36, 89, 46, 97, 34, 56, 78, 65, 83, 59, 74];
N = length(X);

Histogram with bin width 10

Let the bin width be 10, the first bin starts at 10;

%[..., a(i), a(i+1), ...] a(i)<=Bi<a(i+1);
%[10,20),[20,30),...,[90,100];
bin1 = [10,20,30,40,50,60,70,80,90,100];
bin1 = 10:10:100;           % Alternatively, you can use this line to specify the bins.
width1 = ones(1,10)*10;     % Define the width
bincount1 = histc(X,bin1);  % Calculate the count of numbers falling in each bin.
height1 = bincount1./(N*width1); % Calculate the height of each bin.
bar(bin1,height1,'histc');    % Draw the histogram.
xlim([10,100]);  % Specify your scope of view.

Histogram with bin width 30

Let the bin width be 30, the first bin starts at 10;

%[..., a(i), a(i+1), ...] a(i)<=Bi<a(i+1);
%[10,40),[40,70),[70,100];
bin2 = [10,40,70,100];
width2 = ones(1,4)*30;
bincount2 = histc(X,bin2);
height2 = bincount2./(N*width2);
bar(bin2,height2,'histc');
xlim([10,100]);

Histogram with bin width 50

Let the bin width be 50, the first bin starts at 10;

%[..., a(i), a(i+1), ...] a(i)<=Bi<a(i+1);
%[10,60),[60,110];
bin3 = [10,60,110];
width3 = ones(1,3)*50;
bincount3 = histc(X,bin3);
height3 = bincount3./(N*width3);
bar(bin3,height3,'histc');
xlim([10,110]);

Assignments

Question. Plot the histogram in Matlab for Homework Q4, with different bin width [10, 20, 30]