% Purpose
%    gets the variable value in a MxN matrix.
%
% Synopsis
%    slice = mexeps('getslice',varcode,ax_range,row_axis,col_axis)
%
% Description
%    It returns variable value in a MxN matrix. The variable is
%    refered to by its variable code, varcode. The input argument
%    ax_range is a 4x2 matrix containing [lower upper] limits of 
%    x, y, z, and t axis of the variable you want to get and  
%    AT LEAST two of the axes length must equal to 1, i.e. lower 
%    limit equals to upper limit.  The row_axis and col_axis are
%    are numbers: 1 for x-axis, 2 for y-axis, 3 for z-axis and 
%    4 for t-axis; they indicate which axis is in row (M) of the 
%    returned variable and which axis is in column (N) of the 
%    returned variable, respectively.
%
% Examples
%    Open a data file and get slice of temperature variable to
%    matrix with depth as row and time as column.
%
%      currentfile = mexeps('openr','t5n155w.cdf');
%      varcode = 20;
%      ax_range = [[1 1];[1 1];[1 3];[1 5]];
%      temp = mexeps('getslice',varcode,ax_range,3,4);
%	% the size of temp is 3x5
%
% See Also
%    getvar
%