FINDARRAY

Find one array within another.

Description

FINDARRAY Find one array within another
  I = FINDARRAY(A,B,'first') for the array B returns an index array of
  the same size as B containing the smallest absolute index in A for each
  element of B which is a member of A and 0 if there is no such index.
  FINDARRAY(A,B) is the same as FINDARRAY(A,B,'first').
  
  I = FINDARRAY(A,B,'last') for the array B returns an index array of
  the same size as B containing the highest absolute index in A for each
  element of B which is a member of A and 0 if there is no such index.

  I = FINDARRAY(A,B,'all') returns a NDIMS(B)+1 dimensional array such
  that I(:,...,k) contains the k-th absolute index in A for each element
  of B, 0 otherwise.

See also find, ismember

 Example:

 >> findarray(pascal(3),magic(2),'all')

 ans(:,:,1) =
      1 6
      0 5
 ans(:,:,2) =
      2 8
      0 0
 ans(:,:,3) =
     3 0
     0 0
 ans(:,:,4) =
     4 0
     0 0
 ans(:,:,5) =
     7 0
     0 0

• MATLAB release: MATLAB 7.11 (R2010b)

[Mukhtar Ullah]

This function can replace FINDMEMBER that has been removed from the file exchange.

[urs Schwarz (us)]

unfortunately, this solution is several times faster (JIT-acc) and - more importantly - doesn't use as much memory:

ixi=zeros(size(b));
ixa=zeros(size(b));
for i=1:length(a)
ia=strfind(a,a(i));
ib=strfind(b,a(i));
ixi(ib)=ia(1);
ixa(ib)=ia(end);
end

us