PADCAT

concatenate vectors with different lengths by padding with NaN (v1.0, feb 2009)

Description

PADCAT - concatenate vectors with different lengths by padding with NaN
 
    M = PADCAT(V1, V2, V3, ..., VN) concatenates the vectors V1 through VN
    into one large matrix. All vectors should have the same orientation,
    that is, they are all row or column vectors. The vectors do not need to
    have the same lengths, and shorter vectors are padded with NaNs.
    The size of M is determined by the length of the longest vector. For
    row vectors, M will be a N-by-MaxL matrix and for column vectors, M
    will be a MaxL-by-N matrix, where MaxL is the length of the longest
    vector.
 
    Examples:
       a = 1:5 ; b = 1:3 ; c = [] ; d = 1:4 ;
       padcat(a,b,c,d) % row vectors
          % -> 1 2 3 4 5
          % 1 2 3 NaN NaN
          % NaN NaN NaN NaN NaN
          % 1 2 3 4 NaN
       CC = {d.' a.' c.' b.' d.'} ;
       padcat(CC{:}) % column vectors
          % 1 1 NaN 1 1
          % 2 2 NaN 2 2
          % 3 3 NaN 3 3
          % 4 4 NaN NaN 4
          % NaN 5 NaN NaN NaN
 
 
    [M, TF] = PADCAT(..) will also return a logical matrix TF with the same
    size as R having true values for those positions that originate from an
    input vector. This may be useful if any of the vectors contain NaNs.
 
    Example:
        a = 1:3 ; b = [] ; c = [1 NaN] ;
        [M,tf] = padcat(a,b,c)
        % find the original NaN
        [Vev,Pos] = find(tf & isnan(M))
        % -> Vec = 3 , Pos = 2
 
    Scalars will be concatenated into a single column vector.
 
    See also cat, reshape, strvcat, char, horzcat, vertcat, isempty
             nones, group2cell (Matlab File Exchange)

Acknowledgements

The author wishes to acknowledge the following in the creation of this submission:
padadd

• MATLAB release: MATLAB 7.6 (R2008a)

[Kent Conover]

Works as advertised - many thanks!

[Laurence Johns]