+ addition for piece wise linear function with tests

1 files changed, 47 insertions, 2 deletions

diff --git a/test/test_function.py b/test/test_function.py
index 386b999..014ecac 100644
--- a/test/test_function.py
+++ b/test/test_function.py
@@ -22,8 +22,8 @@ def test_pwc():
     
     xp_expected = [0.0, 1.0, 1.0, 2.0, 2.0, 2.5, 2.5, 4.0]
     yp_expected = [1.0, 1.0, -0.5, -0.5, 1.5, 1.5, 0.75, 0.75]
-    assert_array_almost_equal(xp, xp_expected)
-    assert_array_almost_equal(yp, yp_expected)
+    assert_array_almost_equal(xp, xp_expected, decimal=16)
+    assert_array_almost_equal(yp, yp_expected, decimal=16)
 
     assert_almost_equal(f.avrg(), (1.0-0.5+0.5*1.5+1.5*0.75)/4.0, decimal=16)
     assert_almost_equal(f.abs_avrg(), (1.0+0.5+0.5*1.5+1.5*0.75)/4.0,
@@ -49,5 +49,50 @@ def test_pwc():
     assert_array_almost_equal(f1.y, 2*f2.y, decimal=16)
 
 
+def test_pwl():
+    x = [0.0, 1.0, 2.0, 2.5, 4.0]
+    y1 = [1.0, -0.5, 1.5, 0.75]
+    y2 = [1.5, -0.4, 1.5, 0.25]
+    f = spk.PieceWiseLinFunc(x, y1, y2)
+    xp, yp = f.get_plottable_data()
+    
+    xp_expected = [0.0, 1.0, 1.0, 2.0, 2.0, 2.5, 2.5, 4.0]
+    yp_expected = [1.0, 1.5, -0.5, -0.4, 1.5, 1.5, 0.75, 0.25]
+    assert_array_almost_equal(xp, xp_expected, decimal=16)
+    assert_array_almost_equal(yp, yp_expected, decimal=16)
+    
+    avrg_expected = (1.25 - 0.45 + 0.75 + 1.5*0.5) / 4.0
+    assert_almost_equal(f.avrg(), avrg_expected, decimal=16)
+    
+    abs_avrg_expected = (1.25 + 0.45 + 0.75 + 1.5*0.5) / 4.0
+    assert_almost_equal(f.abs_avrg(), abs_avrg_expected, decimal=16)
+
+    f1 = copy(f)
+    x = [0.0, 0.75, 2.0, 2.5, 2.7, 4.0]
+    y1 = [0.5, 1.0, -0.25, 0.0, 1.5]
+    y2 = [0.8, 0.2, -1.0, 0.0, 2.0]
+    f2 = spk.PieceWiseLinFunc(x, y1, y2)
+    f1.add(f2)
+    x_expected = [0.0, 0.75, 1.0, 2.0, 2.5, 2.7, 4.0]
+    y1_expected = [1.5, 1.0+1.0+0.5*0.75, -0.5+1.0-0.8*0.25/1.25, 1.5-0.25,
+                   0.75, 1.5+0.75-0.5*0.2/1.5]
+    y2_expected = [0.8+1.0+0.5*0.75, 1.5+1.0-0.8*0.25/1.25, -0.4+0.2, 1.5-1.0,
+                   0.75-0.5*0.2/1.5, 2.25]
+    assert_array_almost_equal(f1.x, x_expected, decimal=16)
+    assert_array_almost_equal(f1.y1, y1_expected, decimal=16)
+    assert_array_almost_equal(f1.y2, y2_expected, decimal=16)
+
+    f2.add(f)
+    assert_array_almost_equal(f2.x, x_expected, decimal=16)
+    assert_array_almost_equal(f2.y1, y1_expected, decimal=16)
+    assert_array_almost_equal(f2.y2, y2_expected, decimal=16)
+    
+    f1.add(f2)
+    # same x, but y doubled
+    assert_array_almost_equal(f1.x, f2.x, decimal=16)
+    assert_array_almost_equal(f1.y1, 2*f2.y1, decimal=16)
+    assert_array_almost_equal(f1.y2, 2*f2.y2, decimal=16)
+
+
 if __name__ == "__main__":
     test_pwc()