How to normalize a histogram?

I am having an incredible amount of difficulty in finding a direct answer to this question. I have an array S that is 300x1. Using histogram(S) I obtain the following histogram:

This histogram is exactly what I need except for one problem. I want this to be a relative frequency histogram. As in, I want the y-axis values to be a percentage of the total number of data points (300). For example, the bin between 0.5 and 0.6 is approximately 73, so I would want it to read as (73/300) or 0.243.

I have seen many answers to this type of question telling users to use the hist function and then create a bar graph. I do not want a bar graph. I want the x-axis to remain unchanged as the actual data values, NOT as bin numbers. Can anyone help? Thanks!

Answer 1

[Sean de Wolski]

http://www.mathworks.com/help/releases/R2015b/matlab/ref/histogram.html#namevaluepairs

Look at the 'Normalization' property.

[GoBlue19]

Thank you!

histogram(S,'Normalization','probability')

This gave me exactly what I needed!

[Sajid Afaque]

@Sean de Wolski i am having the same issue but since i am using 2013b version the above syntax is not valid. do you have any idea of doing same using hist.

[Owen Tolfrey]

[N,edges] = histcounts(y,'Normalization','probability');

Answer 2

[mayank awasthi]

if we want to find the area under this histogram then how can we do that?

[Moritz Flor]

Extract the bin values from the histogram, add them and multiply them by the bin width:

%%create histogram
x = randn(1000,1);
nbins = 25;
h = histogram(x,nbins)

%%extract parameters
counts = h.Values;
sum_counts = sum(counts);
width = h.BinWidth;

%%area of the histogram
area = sum_counts*width;

Answer 3

[george veropoulos]

hi

i want to normalized the histogram

i use the hist

[f x]=hist(fn,nbins);

dx = diff(x(1:2));

bar(x,f./(sum(f.*dx)));

how i can use the histogram

thank you

[sadegh sehhat]

insted of that you can use this code

if fn is your data set:

histogram(fn,nbins,'Normalization','pdf')