[PYTHON MATRIX-SIG] type coercion one more time
Thu, 25 Jan 96 08:13:02 EST
I've been working to design a stable version of automatic type
coercion that everybody (including myself) can be happy with. The
following is what I have. Much of this is in line with the C rules
for type coercion (at least according to my old K&R). I will use the
standard C type names (double means a python float).
Only the following three automatic coercions are allowed:
1) Any integer type can be coerced to a float, a double, a complex float or
a complex double.
2) A float can only be coerced to a complex float.
3) A double can only be coerced to a complex double.
The following type hierarchy is assumed:
INTEGER < FLOAT < COMPLEX
Within each level there are a number of possible precisions. No
automatic coercion will take place between these precisions.
This remains completely consistent with the existing python automatic
a_t = array([x,y,z,...], 't') # Where t is a legal typecode
1 - signed byte
l - long
f - float
d - double
F - complex float
D - complex double
a_l * a_d = a_d
a_f * a_l = a_f
a_f * a_d = TypeError Exception raised
a_d * a_D = a_D
a_1 * a_l = TypeError Exception raised
Comments? - Jim
MATRIX-SIG - SIG on Matrix Math for Python
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