[Numpy-discussion] Superclassing numpy.matrix: got an unexpected keyword argument 'dtype'
Robert.Conde@sungar...
Robert.Conde@sungar...
Wed Dec 10 06:15:37 CST 2008
Hello,
I'm using numpy-1.1.1 for Python 2.3. I'm trying to create a class that acts just like the numpy.matrix class with my own added methods and attributes. I want to pass my class a list of custom "instrument" objects and do some math based on these objects to set the matrix. To this end I've done the following:
from numpy import matrix
class rcMatrix(matrix):
def __init__(self,instruments):
"""Do some calculations and set the values of the matrix."""
self[0,0] = 100 # Just an example
self[0,1] = 100 # The real init method
self[1,0] = 200 # Does some math based on the input objects
self[1,1] = 300 #
def __new__(cls,instruments):
"""When creating a new instance begin by creating an NxN matrix of
zeroes."""
len_ = len(instruments)
return matrix.__new__(cls,[[0.0]*len_]*len_)
It works great and I can, for example, multiply two of my custom matrices seamlessly. I can also get the transpose. However, when I try to get the inverse I get an error:
> rcm = rcMatrix(['instrument1','instrument2'])
> print rcm
[[ 100. 100.]
[ 200. 300.]]
> print rcm.T
[[ 100. 200.]
[ 100. 300.]]
> print [5,10] * rcm
[[ 2500. 3500.]]
> print rcm.I
Traceback (most recent call last):
File "[Standard]/deleteme", line 29, in ?
File "C:\Python23\Lib\site-packages\numpy\core\defmatrix.py", line 492, in getI
return asmatrix(func(self))
File "C:\Python23\Lib\site-packages\numpy\core\defmatrix.py", line 52, in asmatrix
return matrix(data, dtype=dtype, copy=False)
TypeError: __init__() got an unexpected keyword argument 'dtype'
I've had to overwrite the getI function in order for things to work out:
def getI(self): return matrix(self.tolist()).I
I = property(getI, None, doc="inverse")
Is this the correct way to achieve my goals?
Please let me know if anything is unclear.
Thanks,
Robert Conde
More information about the Numpy-discussion
mailing list