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diff --git a/packages/hmatrix/examples/root.hs b/packages/hmatrix/examples/root.hs
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+-- root finding examples
+import Numeric.GSL
+import Numeric.LinearAlgebra
+import Text.Printf(printf)
+
+rosenbrock a b [x,y] = [ a*(1-x), b*(y-x^2) ]
+
+test method = do
+    print method
+    let (s,p) = root method 1E-7 30 (rosenbrock 1 10) [-10,-5]
+    print s -- solution
+    disp p -- evolution of the algorithm
+
+jacobian a b [x,y] = [ [-a    , 0]
+                     , [-2*b*x, b] ]
+
+testJ method = do
+    print method
+    let (s,p) = rootJ method 1E-7 30 (rosenbrock 1 10) (jacobian 1 10) [-10,-5]
+    print s
+    disp p
+
+disp = putStrLn . format "  " (printf "%.3f")
+
+main = do
+    test Hybrids
+    test Hybrid
+    test DNewton
+    test Broyden
+
+    mapM_ testJ [HybridsJ .. GNewton]