# Matrix Multiplication

A

#### 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

T

#### Thomas Wittek

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/

S

#### 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.

J

#### Jeremy Sanders

sturlamolden said:
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

W

#### 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

Will McGugan

S

#### 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.

J

#### Jeremy Sanders

sturlamolden said:
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.

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.