how to convert empty double into zeros

dear all I have an empty double matrix called Quad, this Quad supposed to be a double with size of 1*31 zeros. how can i please ask matlab that if it finds any empty double convert it to zeros. my code is the following and it says it does not work on double !

idx_9 = cellfun('isempty', Quad);
Quad(idx_9) = {zeros(1,31)};

[Stephen23]

"I have an empty double matrix called Quad"

Then why are you trying to use cellfun, which only works on cell arrays?

Rather than describing your data, please upload it using the paperclip button.

[MAHMOUD ALZIOUD]

it is not data, it is an output, the output must be in the size of 1*31, but since there was no data to analyze then i still receive empty double, i am using the cellfun because i do not know what is the double fun here instead

Answer 1

[Stephen23]

if isempty(Quad)
     Quad = zeros(1,31);
end

[MAHMOUD ALZIOUD]

man you are amazing, thank you