MATLAB: Question about the sign

sign matrix

i have this matrix
H =
     1     1     1     1     1     1     1     1
     1    -1     1    -1     1    -1     1    -1
     1     1    -1    -1     1     1    -1    -1
     1    -1    -1     1     1    -1    -1     1
     1     1     1     1    -1    -1    -1    -1
     1    -1     1    -1    -1     1    -1     1
     1     1    -1    -1    -1    -1     1     1
     1    -1    -1     1    -1     1     1    -1
i did this code H(se+1,:)=2 H(s0+1,:)=5 to put 2 in some rows and 5 in the rest i get this
H =
     2     2     2     2     2     2     2     2
     5     5     5     5     5     5     5     5
     5     5     5     5     5     5     5     5
     2     2     2     2     2     2     2     2
     5     5     5     5     5     5     5     5
     2     2     2     2     2     2     2     2
     2     2     2     2     2     2     2     2
     5     5     5     5     5     5     5     5
it is correct but the problem that i want to keep the sign of H
i have to get this H =
     2      2      2      2     2      2     2      2
     5     -5      5     -5     5     -5     5     -5
     5      5     -5     -5     5      5    -5     -5
     2     -2     -2      2     2     -2    -2      2
     5      5      5      5    -5     -5    -5     -5
     2     -2      2     -2    -2      2    -2      2
     2      2     -2     -2    -2     -2     2      2
     5     -5     -5      5    -5      5     5     -5
help me, Thanks :)

Best Answer

Use sign function
In your case you can use
   H(se+1,:)=2*H(se+1,:)
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