minor fixes

Author: zStupan

fireflyalgorithm/problems.py

@@ -55,9 +55,9 @@ def griewank(x):
 def katsuura(x):
     dim = len(x)
     k = np.atleast_2d(np.arange(1, 33)).T
-    i = np.arange(0, dim * 1)
+    i = np.arange(1, dim + 1)
     inner = np.round(2**k * x) * (2.0 ** (-k))
-    return np.prod(np.sum(inner, axis=0) * (i + 1) + 1)
+    return np.prod(np.sum(inner, axis=0) * i + 1)
 
 
 def levy(x):
@@ -158,7 +158,7 @@ def schaffer2(x):
 def schaffer4(x):
     return (
         0.5
-        + (np.cos(np.sin(x[0] ** 2 - x[1] ** 2)) ** 2 - 0.5)
+        + (np.cos(np.sin(abs(x[0] ** 2 - x[1] ** 2))) ** 2 - 0.5)
         / (1 + 0.001 * (x[0] ** 2 + x[1] ** 2)) ** 2
     )
 
@@ -170,11 +170,11 @@ def schwefel(x):
     )
 
 
-def schwefel21(x):
+def schwefel221(x):
     return np.amax(np.abs(x))
 
 
-def schwefel22(x):
+def schwefel222(x):
     return np.sum(np.abs(x)) + np.prod(np.abs(x))
 
 
@@ -253,8 +253,8 @@ def zakharov(x):
     "schaffer2": schaffer2,
     "schaffer4": schaffer4,
     "schwefel": schwefel,
-    "schwefel21": schwefel21,
-    "schwefel22": schwefel22,
+    "schwefel221": schwefel221,
+    "schwefel222": schwefel222,
     "sphere": sphere,
     "step": step,
     "step2": step2,

tests/test_problems.py

@@ -25,8 +25,8 @@
     schaffer2,
     schaffer4,
     schwefel,
-    schwefel21,
-    schwefel22,
+    schwefel221,
+    schwefel222,
     sphere,
     step,
     step2,
@@ -64,8 +64,8 @@ def test_problem_factory(self):
         self.assertEqual(get_problem("schaffer2"), schaffer2)
         self.assertEqual(get_problem("schaffer4"), schaffer4)
         self.assertEqual(get_problem("schwefel"), schwefel)
-        self.assertEqual(get_problem("schwefel21"), schwefel21)
-        self.assertEqual(get_problem("schwefel22"), schwefel22)
+        self.assertEqual(get_problem("schwefel221"), schwefel221)
+        self.assertEqual(get_problem("schwefel222"), schwefel222)
         self.assertEqual(get_problem("sphere"), sphere)
         self.assertEqual(get_problem("step"), step)
         self.assertEqual(get_problem("step2"), step2)
@@ -175,11 +175,11 @@ def test_schwefel(self):
 
     def test_schwefel21(self):
         x = np.zeros(5)
-        self.assertAlmostEqual(schwefel21(x), 0.0)
+        self.assertAlmostEqual(schwefel221(x), 0.0)
 
     def test_schwefel22(self):
         x = np.zeros(5)
-        self.assertAlmostEqual(schwefel22(x), 0.0)
+        self.assertAlmostEqual(schwefel222(x), 0.0)
 
     def test_sphere(self):
         x = np.zeros(5)
@@ -190,8 +190,8 @@ def test_step(self):
         self.assertAlmostEqual(step(x), 0.0)
 
     def test_step2(self):
-        x = np.full(5, 0.5)
-        self.assertAlmostEqual(step(x), 0.0)
+        x = np.full(5, -0.5)
+        self.assertAlmostEqual(step2(x), 0.0)
 
     def test_styblinski_tang(self):
         x = np.full(5, -2.903534018185960)