Added bitwise operators

pywafo/src/wafo/bitwise.py

@@ -0,0 +1,89 @@
+'''
+Module extending the bitoperator capabilites of numpy 
+'''
+
+from numpy import (bitwise_and, bitwise_or,  #@UnresolvedImport 
+                   bitwise_not, binary_repr, #@UnresolvedImport @UnusedImport
+                   bitwise_xor, where, arange) #@UnresolvedImport @UnusedImport
+#import numpy as np
+__all__ = ['bitwise_and', 'bitwise_or', 'bitwise_not', 'binary_repr', 
+           'bitwise_xor', 'getbit', 'setbit', 'getbits', 'setbits']
+
+def getbit(i, bit):
+    """
+    Get bit at specified position
+    
+    Parameters
+    ----------
+    i : array-like of uints, longs
+        value to 
+    bit : array-like of ints or longs
+        bit position between 0 and the number of bits in the uint class.
+    
+    Examples
+    --------
+    >>> import numpy as np
+    >>> binary_repr(13)
+    '1101'
+    >>> getbit(13,np.arange(3,-1,-1))
+    array([1, 1, 0, 1])
+    >>> getbit(5, np.r_[0:4])
+    array([1, 0, 1, 0])
+    """
+    return bitwise_and(i, 1 << bit) >> bit
+
+def getbits(i, numbits=8):
+    """
+    Returns bits of i in a list
+    """
+    return getbit(i, arange(0, numbits))
+
+def setbit(i, bit, value=1):
+    """
+    Set bit at specified position
+    
+    Parameters
+    ----------
+    i : array-like of uints, longs
+        value to 
+    bit : array-like of ints or longs
+        bit position between 0 and the number of bits in the uint class.
+    value : array-like of 0 or 1
+        value to set the bit to.
+        
+    Examples
+    --------
+    Set bit fifth bit in the five bit binary binary representation of 9 (01001)
+    yields 25 (11001)
+    >>> setbit(9,4)   
+    array(25)
+    """
+    val1 = 1 << bit
+    val0 = bitwise_not(val1)
+    return where((value==0) & (i==i) & (bit==bit), bitwise_and(i, val0),
+                  bitwise_or(i, val1))
+
+def setbits(bitlist):
+    """
+    Set bits of val to values in bitlist
+    """
+#    return bitlist[7]<<7 | bitlist[6]<<6 | bitlist[5]<<5 | bitlist[4]<<4 | \
+#    bitlist[3]<<3 | bitlist[2]<<2 | bitlist[1]<<1 | bitlist[0] 
+    val = 0
+    for i, j in enumerate(bitlist):
+        val |= j << i 
+    return val
+    
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()
+    
+#    t = set(np.arange(8),1,1)  
+#    t=get(0x84,np.arange(0,8))
+#    t=getbyte(0x84)
+#    t=get(0x84,[0, 1, 2, 3, 4, 5, 6, 7])
+#    t=get(0x20, 6)
+#    bit = [0 for i in range(8)]
+#    bit[7]=1
+#    t = setbits(bit)
+#    print(hex(t))