Standard deviation is calculated as follows:

Take the square root of the quotient (from Step 5) Since there are two variables in the formula (x;n) substitute those by x;y where n is the number of points in the graph Initial formula ​sqrt(sigma sum from

i=0 to n(xi -xm)2/(n-1) where xm is the mean data of a set xi is the value of the ith point

@RuslanPozinkevych Thank You for your response. Much obliged, helped me in my work.

The procedures listed below must be taken in order to determine the mean and standard deviation from an FTIR (Fourier Transform Infrared) graph:

Geetika Porwal , in MATLAB you can use the function std(A)

https://www.mathworks.com/help/matlab/ref/std.html

which returns the standard deviation of the elements of array A ...

and,

function mean(A)

https://www.mathworks.com/help/matlab/ref/mean.html

which returns the mean of the elements of A,

good luck