I got a lof of help from the experts in this forum. I resitsted to send a thank you reply for fearing spaming the forum. This time I really want to let the people know that I am really appreciate the great help I got.
 
Please let me know if a simple thank you message is not appropriate in this forum.
 
Numpy makes Pyhton a great tools for processing signal.
 
Thank you very much.
 
Frank

> Date: Mon, 8 Dec 2008 11:30:31 -0600
> From: robert.kern@gmail.com
> To: numpy-discussion@scipy.org
> Subject: Re: [Numpy-discussion] how to create a matrix based on a vector?
>
> On Mon, Dec 8, 2008 at 11:27, frank wang <f.yw@hotmail.com> wrote:
> > Hi,
> >
> > I want to create a matrix based on a vector. It is difficult to describe the
> > issue for me in english. Here is an example.
> >
> > Suppose I have an array([3, 6, 8, 12]), I want to create a range based on
> > each element. In this exampe, let us say want to create 4 number with step
> > 2, so I will have
> >
> > [3, 6, 8, 12
> > 5, 8, 10,14
> > 7, 10,12,16
> > 9, 12,14,18]
> >
> > It is a 4 by 4 maxtric in this example. My original array is quite large.
> > but the range I want to create around the number is not big, it is about 30.
> >
> > Does anyone know how to do this efficiently?
>
> In [1]: from numpy import *
>
> In [2]: a = array([3, 6, 8, 12])
>
> In [4]: b = arange(0, 4*2, 2)[:,newaxis]
>
> In [5]: a+b
> Out[5]:
> array([[ 3, 6, 8, 12],
> [ 5, 8, 10, 14],
> [ 7, 10, 12, 16],
> [ 9, 12, 14, 18]])
>
> --
> Robert Kern
>
> "I have come to believe that the whole world is an enigma, a harmless
> enigma that is made terrible by our own mad attempt to interpret it as
> though it had an underlying truth."
> -- Umberto Eco
> _______________________________________________
> Numpy-discussion mailing list
> Numpy-discussion@scipy.org
> http://projects.scipy.org/mailman/listinfo/numpy-discussion

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