how to plot histogram from an array ?

Hi everyone, what the simplest code to plot a histogram from this table ?

( x-axis for frequencies ; y-axis for the numbers )

Answer 1

[Image Analyst]

Try putting each of those into a vector. The x axis is actually Number, not frequency, and the bin heights (the counts) are actually the frequency. So you'd do

frequency = [3,9,13,21,9,4,1];
Number = linspace(11.945, 12.035, length(frequency));
bar(Number, frequency);
xlabel('Number');
ylabel('Frequency (count)')
grid on;

[Image Analyst]

@noble amin I don't know how you're getting your original numbers but there is a variety of ways to read them in from a text file, like readmatrix(), importdata(), csvread(), etc. Once you have the numbers, if you want to put them into a table variable type you can use table() like this:

frequency = [3,9,13,21,9,4,1];
Number = linspace(11.945, 12.035, length(frequency));
t = table(Number(:), frequency(:), 'VariableNames', {'Number', 'frequency'})

t = 7×2 table
    Number    frequency
    ______    _________

    11.945        3    
     11.96        9    
    11.975       13    
     11.99       21    
    12.005        9    
     12.02        4    
    12.035        1    

bar(t.Number, t.frequency);
xlabel('Number');
ylabel('Frequency (count)');
grid on;

Answer 2

[the cyclist]

Histograms start from the data before they have been binned. You just need a bar chart. If your data are stored in a MATLAB table named tbl, then

bar(tbl.Number,tbl.frequency)

You didn't really tell us how the data are stored, so you may need to manipulate the data first, to get it in the proper format.

[noble amin]

how to create a matlab table named tbl ?

[the cyclist]

How is your data stored now? Can you upload a MAT file with the data? (Use the paperclip icon in the INSERT section of the toolbar.)

For your future reference, uploading an image of your data (as you did in your original question) is not very helpful.