create a multidimensional array in matlab -

create a multidimensional array in matlab -

i creating multidimensional array in matlab has 3 paramter , number , width , height

a = randn(number,width,height)

my problem number dynamic variable increment when find objects in text file. how suppose create number variable dynamic,

i tried didnt worked

a = randn(:,width,height)

i = 0; when (object in text file) = i+1; a(i,:,:) = data; end

data of size - width x height

matlab