Traping Error user input

n=inputdlg('Please input a number more than or equal one:')

I would like to trap the user if they input anything other than numbers more than 1. I have tried loop,isnumeric but they all don't work overally.

Any ideas?

Thank you

Answer 1

[Honglei Chen]

Is this what you want?

n=inputdlg('Please input a number more than or equal one:')
while isempty(str2num(n{1})) || str2num(n{1})<1
  n=inputdlg('Please input a number more than or equal one:')
end

[Rooy]

This way doesn't really work

n =

'b'

Undefined function 'isnumeic' for input arguments of type 'cell'.

Error in Untitled23 (line 2)

while ~isnumeic(n) || n < 1

If I extract from the cell array it would still not work

[Honglei Chen]

I didn't realize you are using inputdlg and I had a typo. I updated the answer

[Rooy]

Thank you it works.

[Rooy]

What if I have more than one input

for instance

n=inputdlg({'Please input a number more than or equal one:';'P'})

while isempty(str2num(n{1})) || str2num(n{1})<1 || isempty(str2num(n{2})) || str2num(n{2})<1

h = errordlg;

waitfor(h)

n=inputdlg({'Please input a number more than or equal one:';'P'})

end

I can't just keep hard coding the loops based on the the amount of inputs. Is there another way

[Honglei Chen]

n=inputdlg({'Please input a number more than or equal one:';'P'})

while any(cellfun(@isempty,cellfun(@str2num,n,'UniformOutput',false))) || ...

any(cellfun(@lt,cellfun(@str2num,n,'UniformOutput',false),...

num2cell(ones(numel(n),1))))

h = errordlg;

waitfor(h)

n=inputdlg({'Please input a number more than or equal one:';'P'})

end

Answer 2

[Image Analyst]

Try this:

clc;    % Clear the command window.
workspace;  % Make sure the workspace panel is showing.
fontSize = 20;
format compact;
% Initialize flag to keep going or not.
keepGoing = true;
userPrompt = 'Enter a number greater than 1';
defaultValue = 42;
while keepGoing
  % Ask user for a number.
  caUserInput = inputdlg(userPrompt, 'Enter the number',1,{num2str(defaultValue)});
  usersValue = round(str2double(cell2mat(caUserInput)));
  % Check for a valid integer.
  if isnan(usersValue)
    % They didn't enter a number.  
    % They clicked Cancel, or entered a character, symbols, or something else not allowed.
    break;
  end
  % See if it's > 1
  if usersValue > 1
    message = sprintf('Success!\n you entered %f.\n', usersValue);
    keepGoing = false; % Bail out
  else
    message = sprintf('Try again.  You entered %f.\n%s', ...
      usersValue, userPrompt);    
    % Keep going.
  end
  uiwait(msgbox(message));
end

[Rooy]

It stalls when I enter the right input after entering a few bad ones.

Thank you

[Rooy]

Where could I get to reprompt the user to enter again?

Thank you

[Image Analyst]

It does not stall. It works fine. I just copied it and ran it again. I was able to enter lots of numbers less than 1 and it kept reprompting the user to enter a number >1. When I finally did enter a number > 1, it exited the while loop. It does exactly what you asked for. If it doesn't, then you must have altered it and broken it.

[Rooy]

Thank you for all the help