about array,arange

[Robert Kern]

Shi Mu wrote:
> On 11/12/05, Robert Kern <robert.kern at gmail.com> wrote:
> 
>>Shi Mu wrote:
>>
>>>i got confused by the use of array and arange.
>>>arange get array and range get list, why we need the two different types?
>>
>>When you're asking questions about a third-party module, it's a good
>>idea to mention the module. In this case you're asking about scipy_core
>>(hopefully) or else numarray or Numeric.
>>
>>The answer to your question is that sometimes we need to get largish
>>arrays (not lists) of consecutive numbers quickly. array(range(N)) is
>>wasteful of memory and time because it has to create a list of Python
>>ints that are simply going to be thrown away once we're done converting
>>to the needed array.
>
> still not clear. can you give an example?
> Thanks! it is from numeric module (really confused by the documentation)

An example of what? How to use arange()? I can't explain it any more
clearly than the docstring does.

In [1]: from Numeric import arange

In [2]: arange?
Type:           builtin_function_or_method
Base Class:     <type 'builtin_function_or_method'>
String Form:    <built-in function arange>
Namespace:      Interactive
Docstring:
    arange(start, stop=None, step=1, typecode=None)

     Just like range() except it returns an array whose type can be
    specified by the keyword argument typecode.

-- 
Robert Kern
rkern at ucsd.edu

"In the fields of hell where the grass grows high
 Are the graves of dreams allowed to die."
  -- Richard Harter