[Tutor] Using numpy Array Capabilities

[Wayne Watson]

Alan Gauld wrote:
>
> "Wayne Watson" <sierra_mtnview at sbcglobal.net> wrote
>
>>  Basically, what I would like to do is to take a list like:
>>
>> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>
>> and convert it to;
>> [['0x0', '0x1', '0x2', '0x3', '0x4'], ['0x5', '0x6', '0x7', '0x8', 
>> '0x9']]
>
> What is the basis of this conversion?
Use of pyfits (FITS formats for astronomy) needs it this way.
> Why did you split it into two lists?
Again, pyfits. It's a matrix/array (their version and used widely in math).
> Why convert into hex strings?
Ultimately, I may have to do it for pyfits. I was preparing for it's use 
there, so it was convenient to use what I had.
The "array" I constructed is the important thing. In math, arrays 
(matrices) are always of the form r*c*p*..., where those symbols are 
integers. r,c, p, ... represent dimensions. x,y,z for example.
>
> If the original list had been:
>
> [3, 5, 78, 21, -3,  7, 5]
>
> What would your output look like?
>
There wouldn't be any. You have 7 elements. The first row of the 
matrix/table/array would be [3,4,78,21], and the second row would not 
contain the same # of elements.
>> That is, it becomes a matrix of 2 rows and 5 columns. I generated the 
>> above from a loop in Python, and generated hex equivalents in the 
>> last list.
>
> It might help to see those loops because it might
> explain the reasoning behind the apparently arbitrary
> decisions.
Explained above.
>
>> Can numpy do this simply without resorting to loops?
>
> Can't help there, I've never used numpy...
>
Well, the FITS and numpy guys (NASA) will be back today, so I'll work it 
out with them.

-- 
           Wayne Watson (Watson Adventures, Prop., Nevada City, CA)

             (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
              Obz Site:  39° 15' 7" N, 121° 2' 32" W, 2700 feet  

           All the neutrons, and protons in the human body occupy 
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