Local maxima part 2

hands_on/first/plus.py

@@ -0,0 +1,3 @@
+
+def plus(x,y):
+    return x + y

hands_on/first/test_first.py

@@ -17,3 +17,11 @@ def test_times_3_string():
     result = times_3(value)
 
     assert result == expected
+
+def test_times_3_list():
+    value = [1]
+    expected = [1,1,1]
+
+    result = times_3(value)
+
+    assert result == expected

hands_on/first/test_plus.py

@@ -0,0 +1,18 @@
+from plus import plus
+import numpy as np
+from math import isclose
+
+def test_plus_123():
+    x = 1
+    y = 2
+    assert plus(x,y) == 3
+
+def test_plus_1dec1_2dec2_3dec3():
+    x = 1.1
+    y = 2.2
+    assert isclose(plus(x,y), 3.3)
+
+def test_plus_with_numpy():
+    x = np.array([[1,1],[1,1]])
+    y = np.array([[2,2],[2,2]])
+    np.testing.assert_equal(plus(x,y), np.array([[3,3],[3,1]]))

hands_on/local_maxima/local_maxima.py

@@ -7,4 +7,28 @@ def find_maxima(x):
     Output:
     idx -- list of indices of the local maxima in x
     """
-    return []
+    local_maxima = []
+    for i in range(1, len(x)-1):
+        first_value = x[i-1]
+        second_value = x[i]
+        third_value = x[i+1]
+        if first_value < second_value and second_value > third_value:
+            local_maxima.append(i)
+        # if i==1 & first_value > second_value:
+        #     local_maxima.append(i)
+    return local_maxima
+
+test_list = [1,3,-2,0,2,1]
+print(find_maxima(test_list))
+
+test_list = [4,2,1,3,1,5]
+print(find_maxima(test_list))
+
+test_list = []
+print(find_maxima(test_list))
+
+test_list = [1,2,2,1]
+print(find_maxima(test_list))
+
+test_list = [1,2,2,3,1]
+print(find_maxima(test_list))

hands_on/local_maxima_part2/local_maxima.py

@@ -1,3 +1,5 @@
+import numpy as np
+
 def find_maxima(x):
     """Find local maxima of x.
 
@@ -7,4 +9,31 @@ def find_maxima(x):
     Output:
     idx -- list of indices of the local maxima in x
     """
-    return []
+    local_maxima = []
+    print('start')
+    if len(x)>0:
+        diff_values = np.diff(x)
+        if np.any(diff_values==0):
+            index_of_plateau = np.argwhere(diff_values==0)
+            if x[int(index_of_plateau)] == np.max(x):
+                local_maxima.append(int(index_of_plateau))
+                return local_maxima
+    for i in range(0, len(x)):
+        if i==0:
+            first_value = x[i]
+            second_value = x[i+1]
+            if first_value > second_value:
+                local_maxima.append(i)
+        elif i==len(x)-1:
+            first_value = x[i-1]
+            second_value = x[i]
+            if first_value < second_value:
+                local_maxima.append(i)
+        else:
+            first_value = x[i-1]
+            second_value = x[i]
+            third_value = x[i+1]
+            if first_value < second_value and second_value > third_value:
+                local_maxima.append(i)
+    return local_maxima
+

hands_on/local_maxima_part2/test_local_maxima.py

@@ -23,8 +23,15 @@ def test_find_maxima_empty():
 
 
 def test_find_maxima_plateau():
-    raise Exception('not yet implemented')
+    values = [1,2,2,1]
+    expected_1 = [1]
+    expected_2 = [2]
+    maxima = find_maxima(values)
+    assert maxima == expected_1 or maxima == expected_2
 
 
 def test_find_maxima_not_a_plateau():
-    raise Exception('not yet implemented')
+    values = [1,2,2,3,1]
+    expected = [3]
+    maxima = find_maxima(values)
+    assert maxima == expected