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+// Copyright (C) 2018 - IIT Bombay - FOSSEE
+//
+// This file must be used under the terms of the CeCILL.
+// This source file is licensed as described in the file COPYING, which
+// you should have received as part of this distribution.  The terms
+// are also available at
+// http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
+// Author:[insert name]
+// Organization: FOSSEE, IIT Bombay
+// Email: toolbox@scilab.in
+
+
+function y = prepad (x, l, c, dim)
+// Calling sequence:
+// y= prepad (x, l)
+// y= prepad (x, l, c)
+// y= prepad (x, l, c, dim)
+// Prepend the scalar value c to the vector x until it is of length
+// l.  If c is not given, a value of 0 is used.
+//
+// If length (x) > l, elements from the beginning of x
+// are removed until a vector of length l is obtained.
+//
+// If x is a matrix, elements are prepended or removed from each row.
+//
+// If the optional argument dim is given, operate along this dimension.
+//
+// If dim is larger than the dimensions of x, the result will have
+// dim dimensions.
+
+//Test cases:
+//prepad ([1,2], 4,0,2)
+//Output: [0,0,1,2]
+
+
+[nargout,nargin]=argn();
+  if (nargin < 2 | nargin > 4)
+    error("wrong number of input arguments");
+  end
+
+  if (nargin < 3 | isempty (c))
+    c = 0;
+  else
+    if (~ isscalar (c))
+      error ("prepad: pad value C must be empty or a scalar");
+    end
+  end
+//dim=1;
+  nd = ndims (x);
+  sz = size (x);
+  if (argn(2) < 4)
+    // Find the first non-singleton dimension.
+    (dim == find (sz > 1, 1)) | (dim == 1);
+  else
+    if (~(isscalar (dim) & dim == fix (dim) & dim >= 1))
+      error ("prepad: DIM must be an integer and a valid dimension");
+    end
+  end
+
+  if (~ isscalar (l) | l < 0)
+    error ("prepad: length L must be a positive scalar");
+  end
+
+  if (dim > nd)
+    sz(nd+1:dim) = 1;
+  end
+
+  d = sz(dim);
+
+  if (d >= l)
+//    idx = repmat ({':'}, nd, 1);
+//    idx(dim) = (d-l+1) : d;
+//    y = x(idx(:));
+      y=x;
+  else
+    sz(dim) = l - d;
+    y = cat (dim, c(ones (sz(1),sz(2))), x);
+  end
+
+endfunction