MATLAB: How to check whether a structure exists

structures

Dear all:

I have a simple question and I can't find an answer on the web…

I have a function that takes arguments in. One argument is a structure array, and inside the function I want to test whether this argument is specified and feed into the function.

I tried isexist(), but this is not for a structure. isstruct() can test whether it is a structure, but the name must exist first. isfield() can check if a structural field exist, but not the structure itself.

So my question is, how to test whether a structure exist?

Any help is appreciated.

Cheers

Ben

Best Answer

exist('structurename','var')

[EDITED, Jan Simon 25-Feb-2012 22:00 UTC]: exists -> exist

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Hi Rebecca,

your problem seems to be closely related to the question of strict data typing for function arguments in Matlab. As far as I know, you cannot do it automatically in Matlab. Matlab functions usually start with checking the number and data type of the input arguments manually, see e.g. gaussmf from the statistics toolbox with 7 lines of checking input arguments and 2 lines of actual code (R2014b).

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Using nargin (or narginchk), is* and error. Check the Fundamental MATLAB Classes to get a feeling of the checks you need to perform.
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Using the inputParser class.
Using try catch
Compile it as a mex-function. You will need to specify the datatypes before compiling.

Best Answer

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