Making sparse signal representation

How to make a sparse signal representation in matlab code.

Answer 1

[Image Analyst]

Did you look up sparse in the help? Do you need further help?

[Tinkul]

sir,

 I have 1280 ecg sample. From that I have to select some non zero coefficient sample. But in 1280 sample there is not any zero coefficient sample,on the other hand there are some sample which are redundant sample,  taking one sample and then making zero the redundant sample associated with that sample can it be possible to make that ecg signal sparse? If it is possible how can make non zero coefficient and remaining other zero? please help.....

[Image Analyst]

Why are you even wanting to mess with sparse when you have only 1280 elements in your sample? That's so tiny that I wouldn't even bother with sparse. Now if you had tens of millions of elements, then you might have a case. But for something the size of a gnat's eyelash, why bother?

[Tinkul]

Suppose i have an image of size 255x255.I have to make it sparse. Then how can I make it sparse? And how can find sparsity of that image.Please help....

[Image Analyst]

From the help:

S = sparse(A) converts a full matrix to sparse form by squeezing out any zero elements

So, how many zeros are in your image? And your image is so tiny that I wonder why you're even bothering with sparse. I never use it and I deal with a lot bigger images than that.