1 files changed, 25 insertions, 26 deletions
diff --git a/macros/idst1.sci b/macros/idst1.sci
index 98fc874..f7fdc6d 100644
--- a/macros/idst1.sci
+++ b/macros/idst1.sci
@@ -1,27 +1,26 @@
-function y = idst1(x,varargin)
-//This function computes the inverse type I discrete sine transform.
-//Calling Sequence
-//Y = idst(X)
-//Y = idst(X, N)
-//Parameters
-//X: Matrix or integer
-//N: If N is given, then X is padded or trimmed to length N before computing the transform.
-//Description
-//This function computes the inverse type I discrete sine transform of Y. If N is given, then Y is padded or trimmed to length N before computing the transform. If Y is a matrix, compute the transform along the columns of the the matrix.
-//Examples
-//idst([1,3,6])
-//ans = 
-//     3.97487  -2.50000   0.97487 
-funcprot(0);
-rhs=argn(2);
-if(rhs<1 | rhs>2) then
-    error("Wrong number of input arguments.");
-end
-select(rhs)
-case 1 then
-    y=callOctave("idst",x);
-case 2 then
-    y=callOctave("idst",x,varargin(1));
-end
-
+/*Description
+        This function computes the inverse type I discrete sine transform of X If N is given,
+        then X is padded or trimmed to length N before computing the transform.
+        If X is a matrix, compute the transform along the columns of the the matrix.
+Calling Sequence
+        Y = idst1(X)
+        Y = idst1(X, N)
+Parameters
+        X: Matrix or integer
+        N: If N is given, then X is padded or trimmed to length N before computing the transform.
+Examples
+        idst1([1,3,6])
+    ans = 
+         3.97487  -2.50000   0.97487 */
+function x = idst1 (y, n)
+  nargin=argn(2)
+  if (nargin < 1 || nargin > 2)
+    error("invalid input arguments")
+  end
+  if nargin == 1,
+    n = size(y,1);
+    if n==1, n = size(y,2); end
+  end
+  x = dst1(y, n) * 2/(n+1);
 endfunction
+