Matrix Multiplication

[amitsoni.1984]

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]

(e-mail address removed):

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/

 

[sturlamolden]

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]

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

 

[Will McGugan]

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

 

[sturlamolden]

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]

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.