CODEWITHSUNDEEP
matlabvalidation
The input-validating guy
The input-validating guy

Reputation: 147

Best practice when validating input in MATLAB

When is it better to use an inputParser than assert when validating input in a MATLAB function. Or is there other, even better tools available?

Upvotes: 5

Views: 1088

Answers (1)

Marc
Marc

Reputation: 3313

I personally found using the inputParser unnecessarily complicated. For Matlab, there are always 3 things to check - Presence, Type and Range/Values. Sometimes you have to assign defaults. Here is some sample code, very typical of my error checking: dayofWeek is the argument, 3rd in the function. (Extra comments added.) Most of this code predates the existence of assert() in Matlab. I use asserts in my later code instead of the if ... error() constructs.

%Presence
if nargin < 3 || isempty(dayOfWeek);
    dayOfWeek = '';
end

%Type
if ~ischar(dayOfWeek);
    error(MsgId.ARGUMENT_E, 'dayOfWeek must be a char array.');
end

%Range
days = { 'Fri' 'Sat' 'Sun' 'Mon' 'Tue' 'Wed' 'Thu' };

%A utility function I wrote that checks the value against the first arg, 
%and in this case, assigns the first element if argument is empty, or bad.
dayOfWeek = StringUtil.checkEnum(days, dayOfWeek, 'assign');

%if I'm this far, I know I have a good, valid value for dayOfWeek

Upvotes: 6

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