Matlab find closest function from plot

I have a probability distribution of some datasets. I have drawn this from the datasets in matlab. The question is that I want to generate similar data with these. I want to get the approximate function in this graph so that I can use it to generate new numbers. Is there a way to make this? either getting the nearest function of that plot OR some other suggestion to make this is appreciated.

I would be grateful if you can help.

I can not post images as I don't have 10 reputation