create "for" condition to multiply specific values ​​of a column

I have these values ​​in an attached matrix called "belem_gldas.mat"

I want to make the following condition: for values ​​less than 1 of all rows in column 6 perform the multiplication by "dia_28"

In short:

I want to multiply all values ​​<1 for all rows in column 6 by "day_28"

dia_28=2419200


for belem_gldas=belem_gldas(belem_gldas(:,6)<1,:)
    belem_gldas(:,6)<1*dia_28
end

Answer 1

[Image Analyst]

Try this:

% Get data.
s = load('belem_gldas.mat')
belem_gldas = s.belem_gldas
dia_28=2419200;

% Get mask = rows where column 6 is less than 1.
mask = belem_gldas(:, 6) < 1;
% For those rows only, multiply the values by dia_28.
belem_gldas(mask, 6) = belem_gldas(mask, 6) * dia_28

[Augusto Gabriel da Costa Pereira]

Thanks a lot for the solution. It is an honor to receive a response from you.