Using the C++ Math Library

Deleting Elements from a Structure Array

There are three kinds of deletion operations you can perform on a structure array.

You can delete:

• An entire structure from the array
• A field from all the structures in the array
• Elements from an array contained in a field

Deleting a Structure from the Array

To delete an entire structure from a structure array, assign the null array to that structure. For example, if you have a three-element array of image structures, you can delete the second image structure like this:

images(2) = empty();

images(2) = [] performs the same operation in MATLAB. The result is a two-element array of image structures.

Deleting a Field from All the Structures in an Array

To delete a field from all the structures in the array, use rmfield(). For example, you can remove the description field from an array of image structures, with this code:

images = rmfield(images, "description");

images = rmfield(images, 'description') performs the same operation in MATLAB.

Note    rmfield() does not allow you to remove a field of a nested structure from a structure array. For example, you cannot remove the day field of the nested date structure with rmfield(images.field("date"), "day"). This is an error in the MATLAB C++ Math Library and in MATLAB.

Deleting an Element from an Array Contained by a Field

To delete an element from an array contained by a field, assign the null array to the indexing expression. For example, to remove the fifth column of the image in the third image structure:

images(3).field("image")(colon(),5) = empty();

images(3).image(:,5) = [] performs the same operation in MATLAB.

Accessing the Contents of Structures Within Cells

Indexing Techniques