MATLAB: Concatenating data from structure array for plotting

Question

I have a structure array with several levels of depth that I am trying to extract a specific set of data from in order to plot it. The plan is to draw individual elements from several different fields, and then combine them into a single array for plotting. I know that normally structures can be concatenated using [], but it doesn't seem to be working for this instance.

plot(x_values,[files([files.Param] == condition).Zone(1).Values(1,4)]);
Expected one output from a curly brace or dot indexing expression, but there were multiple results.

I know that the inner conditional statement is working, as I can extract it and get the appropriate logic matrix, but that means that I am looking at multiple elements of 'files' (which is exactly what I want to do), but they do not seem to be concatenating properly. Any suggestions would be appreciated.

Answer 1

Nested structures do not allow that syntax, so the simplest solution is to use temporary variables to unnest those structures (temporary varaibles will not copy data in memory, so don't worry about using them).

https://www.mathworks.com/matlabcentral/answers/421867-accessing-all-lower-elements-of-a-structure

https://www.mathworks.com/matlabcentral/answers/329538-why-do-i-get-this-error-for-this-non-scalar-structure#comment_436903

https://www.mathworks.com/matlabcentral/answers/408691-is-there-a-way-to-extract-a-set-of-values-from-a-structured-array#comment_586986