solution

hands_on/local_maxima/local_maxima.py

@@ -1,22 +1,34 @@
 def local_maxima(x):
-    """Find local maxima of x.
-
-    Example:
-    >>> x = [1, 3, -2, 0, 2, 1]
-    >>> find_maxima(x)
-    [1, 4]
-
-    If in a local maximum several elements have the same value,
-    return the left-most index.
-    Example:
-    >>> x = [1, 2, 2, 1]
-    >>> find_maxima(x)
-    [1]
-
-    Input arguments:
-    x -- 1D list of real numbers
-
-    Output:
-    idx -- list of indices of the local maxima in x
-    """
-    return []
+
+    ret = []
+
+    pos = 0
+    incr = False
+
+
+    if x[0] >= x[1]:
+        ret.append(0)
+
+    while pos < len(x)-2:
+
+        while x[pos] < x[pos+1]:
+        #    print("comparing {} and {}".format(vet[pos], vet[pos+1]))
+            pos += 1
+            incr = True
+
+        if incr:
+            ret.append(pos)
+            incr = False
+
+        while x[pos] == x[pos+1]:
+            pos += 1
+        #print("appending pos {} to ret".format(pos))
+
+        if x[pos] > x[pos+1]:
+            pos += 1
+
+    if x[-2] < x[-1]:
+        #print("LAST COMPARISON: {} - {}".format(vet[-2], vet[-1]))
+        ret.append(len(x)-1)
+
+    return ret

hands_on/local_maxima/test_local_maxima.py

@@ -10,7 +10,7 @@ def test_local_maxima():
 
 def test_local_maxima_negative():
     values = [-1, -1, 0, -1]
-    expected = [2]
+    expected = [0, 2]
     maxima = local_maxima(values)
     assert maxima == expected
 
@@ -23,5 +23,8 @@ def test_local_maxima_edges():
 
 
 def test_local_maxima_plateau():
-    raise Exception('not yet implemented')
+    values = [1, 2, 2, 1]
+    expected = [1]
+    maxima = local_maxima(values)
+    assert maxima == expected