st: Mata looping question

[Anna Reimondos <areimondos@gmail.com>]

Hello,
I am just starting to try and learn how to use mata and have a
question about a simple loop command.

For example if I have one original matrix called 'a'

matrix a=(1,0,0\0,2,1\0,1,0\0,0,0)
matrix list a

I then want to create another matrix 'b' which is equal to 'a' but
where every element has been shifted up one row and across one column.


matrix b = J(4,3,0)

forvalues i = 1/4 {
local x=`i'+1
	forvalues j = 1/3 {
	local y=`j'+1
		 matrix b[`i',`j']= a[`x',`y']
	}
}
matrix list b


I have tried reading a lot of tutorials about using mata but am still
confused about how I would go about doing this in mata

Any advice that would help me along my way would be much appreciated,
Thanks
Anna
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