Error clicking the GUI interface button in matlab

Unable to perform assignment because the size of the left side is 1-by-1 and the size of the right side is 1-by-0.

Error in matriz_destino (line 10)
mat(2,1) = double(char(get(findobj(gcf,'Tag','p14'),'String')));
 
Error while evaluating UIControl Callback.

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Incapaz de realizar a atribuição porque o tamanho do lado esquerdo é 1 por 1 e o tamanho do lado direito é 1 por 0.
Erro em matriz_destino (linha 10)
mat (2,1) = double (char (get (findobj (gcf, 'Tag', 'p14'), 'String')));
 
Erro ao avaliar o retorno de chamada UIControl.

[Guilherme Alves]

Part of code:

mat = zeros(5,5); % matriz de zeros 5x5.

mat(5,1) = double(char(get(findobj(gcf,'Tag','p11'),'String')));
mat(4,1) = double(char(get(findobj(gcf,'Tag','p12'),'String')));
mat(3,1) = double(char(get(findobj(gcf,'Tag','p13'),'String')));
mat(2,1) = double(char(get(findobj(gcf,'Tag','p14'),'String')));
mat(1,1) = double(char(get(findobj(gcf,'Tag','p15'),'String')));

[Adam Danz]

"the size of the right side is 1-by-0"

"o tamanho do lado direito é 1 por 0"

The result on the right side of the equal sign is empty.

This could be because findobj(gcf,'Tag','p11') is not finding any objects:

findobj(gcf,'Tag','p11')
ans = 
  0×0 empty GraphicsPlaceholder array.


double(char(get([],'String')))
ans =
     []

But even if it did find the correct object, it doesn't look like you're converting the string correctly. After you figure out the correct findobj() inputs, assuming the string is a number, try,

h = findobj(____); 
mat(5,1) = str2double(get(h,'string'));
% or 
mat(5,1) = str2double(h.String);