1 files changed, 77 insertions, 0 deletions
diff --git a/numpy/lib/ufunclike.py b/numpy/lib/ufunclike.py
new file mode 100644
index 000000000..7e8d44c7d
--- /dev/null
+++ b/numpy/lib/ufunclike.py
@@ -0,0 +1,77 @@
+"""
+Module of functions that are like ufuncs in acting on arrays and optionally
+storing results in an output array.
+"""
+__all__ = ['fix', 'isneginf', 'isposinf', 'sign', 'log2']
+
+import numeric as nx
+from numeric import asarray, empty, empty_like, isinf, signbit, zeros
+import umath
+
+def fix(x, y=None):
+    """ Round x to nearest integer towards zero.
+    """
+    x = asarray(x)
+    if y is None:
+        y = nx.floor(x)
+    else:
+        nx.floor(x, y)
+    if x.ndim == 0:
+        if (x<0):
+            y += 1
+    else:
+        y[x<0] = y[x<0]+1
+    return y
+
+def isposinf(x, y=None):
+    """Return a boolean array y with y[i] True for x[i] = +Inf.
+
+    If y is an array, the result replaces the contents of y.
+    """
+    if y is None:
+        y = empty(x.shape, dtype=nx.bool_)
+    umath.logical_and(isinf(x), ~signbit(x), y)
+    return y
+
+def isneginf(x, y=None):
+    """Return a boolean array y with y[i] True for x[i] = -Inf.
+
+    If y is an array, the result replaces the contents of y.
+    """
+    if y is None:
+        y = empty(x.shape, dtype=nx.bool_)
+    umath.logical_and(isinf(x), signbit(x), y)
+    return y
+
+def sign(x, y=None):
+    """sign(x) gives an array with shape of x with elexents defined by sign
+    function:  where x is less than 0 return -1, where x greater than 0, a=1,
+    elsewhere a=0.
+    """
+    x = asarray(x)
+    if y is None:
+        y = zeros(x.shape, dtype=nx.int_)
+    if x.ndim == 0:
+        if x < 0:
+            y -= 1
+        elif x > 0:
+            y += 1
+    else:
+        y[x<0] = -1
+        y[x>0] = 1
+    return y
+
+_log2 = umath.log(2)
+def log2(x, y=None):
+    """Returns the base 2 logarithm of x
+
+    If y is an array, the result replaces the contents of y.
+    """
+    x = asarray(x)
+    if y is None:
+        y = umath.log(x)
+    else:
+        umath.log(x, y)
+    y /= _log2
+    return y
+