Try this:
carga = input('Insira o número total de cargas : ');
cargas= 1:carga;
potencia = zeros(1, carga); % Preallocate space.
defaultValue = {'0'};
titleBar = 'Enter a number';
for k = 1 : carga
%Meu input de potência deve pedir a quantidade de cargas
userPrompt = {sprintf('Enter value #%d : ', k)};
% Keep asking user for something until they enter a number.
caUserInput = '';
while isempty(caUserInput)
% Ask user for a number.
caUserInput = inputdlg(userPrompt, titleBar, 1, defaultValue);
if isempty(caUserInput),break,end % Bail out if they clicked Cancel.
% Convert to floating point from string.
usersValue = str2double(caUserInput{1})
% Check usersValue1 for validity.
if isnan(usersValue)
% If it's a NAN, they didn't enter a number.
% They clicked Cancel, or entered a character, symbols, or something else not allowed.
% Convert the default from a string and stick that into usersValue1.
usersValue = str2double(defaultValue{1});
message = sprintf('I said it had to be a number.', usersValue);
uiwait(warndlg(message));
caUserInput = '';
end
end
% Value is good (a number) if we get here.
potencia(k) = usersValue;
end
