How to modify table elements without using a for loop?

E.g.

    % t is a table
    for (yy = 1:size(t,1))
        if strcmp('cat',t.animal(yy))
            t.value(yy) = t.value(yy)*-1;
        end
    end

[madhan ravi]

give a short example and upload your table

Answer 1

[Stephen23]

Your original idea of using strcmp was perfect, there is no need to complicate things with strings:

value = [1;2;3;4]
animal = {'cat';'dog';'cat';'dog'}
t = table(value,animal)
idx = strcmp(t.animal,'cat')
t.value(idx) = -t.value(idx)

[Elissa]

Perfect, thanks.

[Peter Perkins]

One addition to Stephen's sol'n: if animal is representative of what your actual data look like, you should consider using a categorical variable. You would then change one line

idx = (t.animal == 'cat');

but also you might find working with that variable elsewhere much simpler.