Determining how many "peaks" in a graph

Hello community,

I currently have two different types of vectors, where the values in the vector represent the y-value of the plot and the x-value is taken from the index of that respective value.

When plotted, these vectors would either result in a graph with one peak, or two peaks. I am trying to find a way to determine how many "peaks" there are.

Below I have attached two examples of graph I have.

One peak - http://i.imgur.com/sY8gt.jpg Two peaks - http://imgur.com/sY8gt,pIThb#1

Answer 1

[José-Luis]

http://www.mathworks.com/matlabcentral/fileexchange/4242

Answer 2

[Star Strider]

Another option from the File Exchange is Peak Fitter.

Answer 3

[Image Analyst]

Here's a review of several peak finding algorithms: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2631518/

Here's another peak detection script:

% Eli Billauer, 3.4.05 (Explicitly not copyrighted). % http://billauer.co.il/peakdet.html % This function is released to the public domain; Any use is allowed.