AppendMatrix

  AppendMatrix appends the contents of a matrix to a variable in a MAT-file

  Example:
  AppendMatrix(FILENAME, VARNAME, NEWDATA)

  FILENAME is a string with the name of the file (which should be a v6
  MAT-file).
  VARNAME is a string with the name of the target variable.
  NEWDATA is the matrix containing the data to add to VARNAME

  The data in NEWDATA are added to the highest existing dimension of
  VARNAME. E.g. if VARNAME is a 100x100x21 matrix on disc and NEWNAME is
  100x100x3, the resulting VARNAME will be 100x100x24.

  AppendMatrix can also add a submatrix following a call to AddDimension
  e.g.:
  x=zeros(2,2,2)
  save myfile x -v6
  AddDimension('myfile','x')% Create a 2x2x2x1 matrix in the file
  AddMatrix('myfile','x',x)% place x in x(:,:,:,2)
  load myfile x
  AddMatrix('myfile','x',x)% adds x to x(:,:,:,3:4)

  Restrictions: VARNAME must be the name of the final variable in FILENAME.
  NEWNAME and VARNAME must have identical dimensions below
  the highest dimension of VARNAME. The class of VARNAME on disc must be
  the same as NEWNAME (use RestoreDiscClass if need be) and both must be
  real valued.

  To append data to a vector, use AppendVector instead
  For 2D matrices, AppendColumns and AppendMatrix produce identical results

  See Also RestoreDiscClass, AppendVector, AppendColumns
 __________________________________________________________________________

  This program is distributed without any warranty,
  without even the implied warranty of fitness for a particular purpose.
 __________________________________________________________________________

  Author: Malcolm Lidierth 11/06
  Copyright © The Author & King's College London 2006
 __________________________________________________________________________