How to overwrite part of a matrix by a function of the row number.

I want to overwrite part of a matrix by a function of the row number.

For example, let

M=rand(10,5) and the function of row number:

f(ROW)=ROW^2.

This function should apply in the range from 1:5 for all columns.

Thus the overwritten matrix N would have the following components

1 1 1 1 1

4 4 4 4 4

9 9 9 9 9

16 16 16 16 16

25 25 25 25 25

0.0620452213196326 0.533771951767000 0.526102465795561 0.337583864052045 0.0513318861123711

0.298243971887764 0.109154212042459 0.729709448223228 0.607865907262946 0.0728852990989761

0.0463512648981808 0.825808857855598 0.707253485315422 0.741254049502218 0.0885274596747204

0.505428142457703 0.338097718802172 0.781377051799277 0.104813241973500 0.798350864113952

0.761425886690113 0.293973053026484 0.287976975614171 0.127888379782995 0.943008139570703

ONLY the initial 5 rows are changed by the power of row number

and ALL columns were modified likewise.

I tried the following approach:

M=rand(10,5);

r=1:1:5;

f=r'.^2;

M(1:5,:)=f;

but did not work.

I hope someone know how to correct this command or to suggest something new.

Thank your for your help

Emerson

Answer 1

[Walter Roberson]

for r = 1:5
  M(r,:) = r^2;
end

Answer 2

[Andrei Bobrov]

without loop for

r = 1:5;
M(r,:) = r.'.^2*ones(1,size(M,2))

[Emerson De Souza]

Thank you Andrei,

your suggestion is definitely valid in particular if a loop

is not desired.

Have a nice day

Emerson