index in matrix using loop

hi i have an matrix in my code that i want to do some calculation on each index in it so first of all i want to check if that index is greater then 0 then i multiply by area then store it in new varible calld fill

if not i multiple this index with area then store it in variable calld fill

how can i do it

[KALYAN ACHARJYA]

It would be helpful to give exact answered, if you can elaborate the question with example.

[dpb]

I'd guess it mandatory to give an example or at least clarify because as written the result is the same for either case...

[mohamed gamal]

0.500000000000000	0.500000000000000
0.250000000000000	0.500000000000000
-0.500000000000000	-0.500000000000000 

like this one and i want to do if the number in the index is + then multiple *AREA+fill

if its - then cut= the numer in matrix*Area +cut

Answer 1

[Kevin Phung]

m = [0.5 0.5; 0.25 0.5; -0.5 -0.5] % your sample matrix

f = m(m>0) * A + fill
c = m(m<0) *A + cut

^ this only return the values that meet the positive/neg criteria. If you want to keep the same dimensions then do this:

new_m = m; %copy
new_m(m>0) = m(m>0) * A + fill; %operate on positives
new_m(m<0) = m(m<0) * A - cut;