1 files changed, 32 insertions, 0 deletions
diff --git a/gensvm/util.py b/gensvm/util.py
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+++ b/gensvm/util.py
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+"""
+Utility functions for GenSVM
+
+"""
+
+
+import numpy as np
+
+
+def get_ranks(x):
+    """
+    Rank data in an array. Low values get a small rank number. Ties are broken 
+    by assigning the lowest value.
+
+    Examples
+    --------
+    >>> x = [7, 0.1, 0.5, 0.1, 10, 100, 200]
+    >>> get_ranks(x)
+    [4, 1, 3, 1, 5, 6, 7]
+
+    """
+    x = np.ravel(np.asarray(x))
+    l = len(x)
+    r = 1
+    ranks = np.zeros((l, ))
+    while not all([k is None for k in x]):
+        m = min([k for k in x if not k is None])
+        idx = [1 if k == m else 0 for k in x]
+        ranks = [r if idx[k] else ranks[k] for k in range(l)]
+        r += sum(idx)
+        x = [None if idx[k] else x[k] for k in range(l)]
+    return ranks