From 197e88c3b56d28840217010a2871c6ea3a4dd1a4 Mon Sep 17 00:00:00 2001
From: Alberto Ruiz <aruiz@um.es>
Date: Wed, 21 May 2014 10:30:55 +0200
Subject: update dependencies, move examples etc

---
 packages/gsl/src/Numeric/GSL/Polynomials.hs | 57 +++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 packages/gsl/src/Numeric/GSL/Polynomials.hs

(limited to 'packages/gsl/src/Numeric/GSL/Polynomials.hs')

diff --git a/packages/gsl/src/Numeric/GSL/Polynomials.hs b/packages/gsl/src/Numeric/GSL/Polynomials.hs
new file mode 100644
index 0000000..b1be85d
--- /dev/null
+++ b/packages/gsl/src/Numeric/GSL/Polynomials.hs
@@ -0,0 +1,57 @@
+{- |
+Module      :  Numeric.GSL.Polynomials
+Copyright   :  (c) Alberto Ruiz 2006
+License     :  GPL
+Maintainer  :  Alberto Ruiz
+Stability   :  provisional
+
+Polynomials.
+
+<http://www.gnu.org/software/gsl/manual/html_node/General-Polynomial-Equations.html#General-Polynomial-Equations>
+
+-}
+
+
+module Numeric.GSL.Polynomials (
+    polySolve
+) where
+
+import Data.Packed
+import Numeric.GSL.Internal
+import Data.Complex
+import System.IO.Unsafe (unsafePerformIO)
+
+#if __GLASGOW_HASKELL__ >= 704
+import Foreign.C.Types (CInt(..))
+#endif
+
+{- | Solution of general polynomial equations, using /gsl_poly_complex_solve/. 
+
+For example, the three solutions of x^3 + 8 = 0
+
+>>> polySolve [8,0,0,1]
+[(-2.0) :+ 0.0,1.0 :+ 1.7320508075688776,1.0 :+ (-1.7320508075688776)]
+
+
+The example in the GSL manual: To find the roots of x^5 -1 = 0:
+
+>>> polySolve [-1, 0, 0, 0, 0, 1]
+[(-0.8090169943749472) :+ 0.5877852522924731,
+(-0.8090169943749472) :+ (-0.5877852522924731),
+0.30901699437494756 :+ 0.9510565162951535,
+0.30901699437494756 :+ (-0.9510565162951535),
+1.0000000000000002 :+ 0.0]
+
+-}  
+polySolve :: [Double] -> [Complex Double]
+polySolve = toList . polySolve' . fromList
+
+polySolve' :: Vector Double -> Vector (Complex Double)
+polySolve' v | dim v > 1 = unsafePerformIO $ do
+    r <- createVector (dim v-1)
+    app2 c_polySolve vec v vec r "polySolve"
+    return r
+             | otherwise = error "polySolve on a polynomial of degree zero"
+
+foreign import ccall unsafe "gsl-aux.h polySolve" c_polySolve:: TV (TCV Res)
+
-- 
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