Help me on function definition

[Michael Wieher]

No problem...

your def needs a colon..

def function(params):

yours lacks it =) thats all

On Fri, Mar 28, 2008 at 8:47 PM, aeneng <aeneng at yahoo.com> wrote:

> Hello everyone,
>
> I am just starting to use python in numerical cacluation.
> I need you to help me to see what's wrong with the following piece of
> codes, which computes the cross product of two vectors and returns
> the result. u and v are two 3x1 matrix.
>
> when I import the function, error message show like this
> >>> import cross
> Traceback (most recent call last):
>  File "<stdin>", line 1, in ?
>  File "cross.py", line 8
>    ppp2=u[2]*v[0]-u[0]*v[2]
>    ^
> SyntaxError: invalid syntax
>
> WHAT IS WRONG WITH MY CODE?
>
> I appreciate your help.
>
> ##here is the function definition.
> ##cross.py##
> def cross(u,v)
>    """input two vectors u and v in 3-D space,
>       output a cross product of vector w, in column or in row
> accordingly."""
>    ppp1,ppp2,ppp3=0.0,0.0,0.0
>    ppp1=u[1]*v[2]-u[2]*v[1]
>    ppp2=u[2]*v[0]-u[0]*v[2]
>    ppp3=u[0]*v[1]-u[1]*v[0]
>    # store the result of the cross product in u
>    u[0]=ppp1
>    u[1]=ppp2
>    u[2]=ppp3
>    return u #return the cross product of vector u x v.
> if __name__=="__main__":
>        from cvxopt.base import matrix
>        u=matrix([1.0,0.0,0.0],(3,1))
>        v=matrix([0.0,1.0,0.0],(3,1))
>        print cross(u,v)
>        print "file name is %s" %__name__
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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