Fourier, minimization, polySolve

1 files changed, 21 insertions, 2 deletions

diff --git a/lib/Data/Packed/Matrix.hs b/lib/Data/Packed/Matrix.hs
index 6ea76c0..ec5744d 100644
--- a/lib/Data/Packed/Matrix.hs
+++ b/lib/Data/Packed/Matrix.hs
@@ -14,7 +14,7 @@
 
 module Data.Packed.Matrix (
     Matrix(rows,cols), Field,
-    toLists, (><), (>|<),
+    toLists, (><), (>|<), (@@>),
     trans,
     reshape,
     fromRows, toRows, fromColumns, toColumns,
@@ -22,7 +22,9 @@ module Data.Packed.Matrix (
     flipud, fliprl,
     liftMatrix, liftMatrix2,
     multiply,
-    subMatrix, diag, takeDiag, diagRect, ident
+    subMatrix,
+    takeRows, dropRows, takeColumns, dropColumns,
+    diag, takeDiag, diagRect, ident
 ) where
 
 import Data.Packed.Internal
@@ -69,3 +71,20 @@ r >|< c = f where
         | otherwise    = error $ "inconsistent list size = "
                                  ++show (dim v) ++"in ("++show r++"><"++show c++")"
         where v = fromList l
+
+----------------------------------------------------------------
+
+-- | Creates a matrix with the first n rows of another matrix
+takeRows :: Field t => Int -> Matrix t -> Matrix t
+takeRows n mat = subMatrix (0,0) (n, cols mat) mat
+-- | Creates a copy of a matrix without the first n rows
+dropRows :: Field t => Int -> Matrix t -> Matrix t
+dropRows n mat = subMatrix (n,0) (rows mat - n, cols mat) mat
+-- |Creates a matrix with the first n columns of another matrix
+takeColumns :: Field t => Int -> Matrix t -> Matrix t
+takeColumns n mat = subMatrix (0,0) (rows mat, n) mat
+-- | Creates a copy of a matrix without the first n columns
+dropColumns :: Field t => Int -> Matrix t -> Matrix t
+dropColumns n mat = subMatrix (0,n) (rows mat, cols mat - n) mat
+
+----------------------------------------------------------------