discrte to softmax : Attempt to grow array along ambiguous dimension

Hello

Im trying to run below function but constantly getting error

Attempt to grow array along ambiguous dimension.

Error in discrete2softmax (line 5)

s_m([1:sNum] + (inp'-1)*sNum) = 1;%problem

I know its caused becouse target is larger then array but please help how i should change my code to make it work

function s_m = discrete2softmax(inp,nmax)
% Convert discrete data into softmax
sNum = size(inp,1);
s_m = zeros(sNum,nmax);
s_m([1:sNum] + (inp'-1)*sNum) = 1;%problem
end

[Walter Roberson]

https://www.mathworks.com/matlabcentral/answers/382816-attempt-to-grow-array-along-ambiguous-dimension#answer_305281

[Matt J]

Tomasz Kaczmarski's comment moved here

thanks for explanation my arrays look like in workspace on left i suppose i should change 1 to 6 then ? but in this case im getting another error

[Walter Roberson]

Change the [] to ()

[Tomasz Kaczmarski]

thanks changing brackets improved code but i still got error

after more debbugging i think i know where my problem is

if s_m got mix of 0 and 1 it work well if i load 0 ( as on screen) only it fails

how to change function to move forward without failing if s_m got zeros only

Answer 1

[Matt J]

I know its caused becouse target is larger then array but please help how i should change my code to make it work

Did you intend to add data at locations outside the bounds of s_m? If so, you would have to do so with 2D subscript indexing, rather than with a 1D linear index, e.g.,

>> s_m=rand(2)

s_m =

    0.7088    0.9239
    0.1146    0.7881

>> s_m(3,4)=1

s_m =

    0.7088    0.9239         0         0
    0.1146    0.7881         0         0
         0         0         0    1.0000