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Create a new array of structures from another array of structures just keeping some fields

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Let's assume I have an array of N structures called array with fields a, b and c. I was wondering if there is any closed form of creating a new array of structures (lets called it newArray) from the original array but with only some of its fields (e.g. a and b). I think this can be a quite common task and I would be surprised if there were no close form of performing it in Matlab.
I have found two ways of performing this:
  1. Copying field by field like:[newArray.a] = array.a;[newArray.b] = array.b;
  2. Copying the whole array of structures and removing the unwanted fields:newArray = array;newArray = rmfields(newArray,'c')
However, none of them looks elegant to me. I think there might be a way of copying the array indicating the fields you want to keep.
Any help on this? thanks in advance!

Answers (1)

Walter Roberson
Walter Roberson on 28 Jan 2016
Some people would use struct2cell() and extract portions of the result and then cell2struct() that. But copying by field would be faster.
  1 Comment
Miguel
Miguel on 28 Jan 2016
Many thanks for the answer. Still I am surprised that there is no function for performing this.
By the way, I have a related question on this (I think this is an easier one). Imagine the data of field a in the original array were angular values expressed in degrees but in the new array I want them to be in radians. How can do this?
If I try it by running [newArray.a] = pi/180*array.a I get a "Too many arguments"error for * operation. Any advice on this?
Thanks!

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