Add the Wood() test function and some tests.

[octave.git] / optimization / test_functions / wood_gradient.m

diff --git a/optimization/test_functions/wood_gradient.m b/optimization/test_functions/wood_gradient.m
new file mode 100644 (file)
index 0000000..f4dde78
--- /dev/null
+++ b/optimization/test_functions/wood_gradient.m
@@ -0,0 +1,11 @@
+function g = wood_gradient(x1, x2, x3, x4)
+  ##
+  ## The gradient of the Wood function. See wood.m for more information.
+  ##
+  f_x1 = 400*(x1^2 - x2)*x1 + 2*x1 - 2;
+  f_x2 = -200*x1^2 + 220.2*x2 + 19.8*x4 - 40;
+  f_x3 = 360*(x3^2 - x4)*x3 + 2*x3 - 2;
+  f_x4 = -180*x3^2 + 19.8*x2 + 200.2*x4 - 40;
+
+  g = [f_x1; f_x2; f_x3; f_x4];
+end