Matrix Multiplication

[amitsoni.1984@gmail.com]

Hi,

Is there any direct function for matrix multiplication in Python or
any of its packages? or do we have to multiply element by element?

Thank you,
Amit

[Thomas Wittek]

Re: Matrix Multiplication

amitsoni.1984@g mail.com:

Is there any direct function for matrix multiplication in Python or
any of its packages? or do we have to multiply element by element?

First hit on google for "python matrix":

http://matpy.sourceforge.net/

--
Thomas Wittek

http://gedankenkonstrukt.de/

Jabber: streawkceur@jab ber.i-pobox.net

[sturlamolden]

Re: Matrix Multiplication

On Jun 17, 10:52 pm, "amitsoni.1...@ gmail.com" <amitsoni.
1...@gmail.comw rote:

Hi,
>
Is there any direct function for matrix multiplication in Python or
any of its packages? or do we have to multiply element by element?

Use numpy: www.scipy.org

NumPy has a matrix type that overloads the * operator.

[Jeremy Sanders]

Re: Matrix Multiplication

sturlamolden wrote:

Use numpy: www.scipy.org
>
NumPy has a matrix type that overloads the * operator.

Just a tiny followup, which may be important unless you carefully read the
documentation. The "*" operator doesn't do matrix multiplication for normal
numpy arrays - you do need to use its special matrix type to get this. You
can use the dot function to get matrix multiplication with its normal
arrays.

Jeremy

--
Jeremy Sanders

http://www.jeremysanders.net/

[Will McGugan]

Re: Matrix Multiplication

amitsoni.1984@g mail.com wrote:

Hi,
>
Is there any direct function for matrix multiplication in Python or
any of its packages? or do we have to multiply element by element?

If you want a pure Python module for 4x4 matrices, then you may want to
look at Game Objects

http://code.google.com/p/gameobjects/

Will McGugan
--

http://www.willmcgugan.com

[sturlamolden]

Re: Matrix Multiplication

On Jun 18, 11:20 am, Jeremy Sanders <jeremy
+complangpyt... @jeremysanders. netwrote:

NumPy has a matrix type that overloads the * operator.

Just a tiny followup, which may be important unless you carefully read the
documentation. The "*" operator doesn't do matrix multiplication for normal
numpy arrays

That's what I wrote: "NumPy has a matrix type." It is called called
numpy.matrix.

I did not suggest using the array type numpy.array.

Reading carefully is indeed important...

[Jeremy Sanders]

Re: Matrix Multiplication

sturlamolden wrote:

That's what I wrote: "NumPy has a matrix type." It is called called
numpy.matrix.
>
I did not suggest using the array type numpy.array.
>
Reading carefully is indeed important...

I know what you wrote and you are strictly correct. I was just clarifying it
for a reader who may not have instantly realised that there were multiple
array types in numpy (I didn't for a while), and could have wasted many
hours and been discouraged.

Explaining clearly is indeed important.

--
Jeremy Sanders

http://www.jeremysanders.net/