CATSTRUCT is the jCommon module of jLab.

 CATSTRUCT  Concatenates the array elements of a cell array of structures.
 
    Let C be a cell array of M structures having N identical fields, where 
    all of the fields are themselves arrays,
          
       C{1}.F1=A11, C{1}.F2=A12, ... , C{1}.FN=A1N
       C{2}.F1=A21, C{2}.F2=A22, ... , C{2}.FN=A2N
          :        :        :        :        :
       C{M}.F1=AM1, C{2}.F2=AM2, ... , C{M}.FN=AMN
    
     and where all the AMN for any particular field (F1,say), have the same
     number of columns, that is, SIZE(A11,2)=SIZE(A21,2)= ... =SIZE(AM1,2).
 
     S=CATSTRUCT(C) then returns a structure in which all fields of the
     same type have been concatenated:
 
       SNEW.F1=[A11;   SNEW.F2=[A12;    ...    SNEW.FN=[A1N;
                A21;            A22;    ...             A2N;
                 :               :      ...              :
                AM1]            AM2]    ...             AMN];
 
    Note S is a single structure, whereas C is a cell array of structures.
 
    As a simple example, with C{1}.F=[1;2] and C{2}.F=[3;4], S=catstruct(C)
    returns S with a field F such that S.F=[1;2;3;4].
 
    One use of CATSTRUCT is in concatentating output from multiple cores
    when using SPMD in the parallel computing toolbox. 
 
    SNEW=CATSTRUCT(S,INDEX) only concatenates those fields listed in INDEX.
    Here index is a list of numbers indicating the fields by the order in 
    which they appear, e.g., INDEX=1:10 concatenates the first 10 fields.
 
    Usage:  snew=catstruct(s);
            snew=catstruct(s,index);
    _________________________________________________________________
    This is part of JLAB --- type 'help jlab' for more information 
    (C) 2003--2021 J.M. Lilly --- type 'help jlab_license' for details