Confused about extending.

Joonas Paalasmaa joonas at olen.to
Thu Feb 22 14:44:59 CET 2001


>> I have made the following C-function and now I would like to
>> use it via Python in that way, that it would
>> manipulate Python lists smoothedValues and originalValues.
>> But I am just a beginner with C and I got confused with extending HowTo.
>> I would be glad if someone would explain how to manipulate the code to
>> make it extendingable.
>> 
>> Joonas.
> 
> 
> I'm puzzled as to why you have implemented this function in C instead of
> Python.  Is it for
> speed?  Just how big ARE your lists?

My lists are big so that is the reason why I have to make
the processing with C. But the frontend must be Python and C-module
would be used from Python. For example:

##############
import cListprocessor

list = [1,2,3,4,5,6,7,8,9,15,9,8,7,6,5,4,3,2,1]

processedList = cListprocessor.SmoothedList(list)
##############


- Joonas Paalasmaa

>> void SmoothedList(double *originalValues, double *smoothedValues,
>>         int listSize, int filterSize)
>> {
>>         double tmpResult;
>>         int i, j;
>>         int iterations = listSize - filterSize + 1;
>> 
>>         for(i = 0; i < iterations; i++)
>>         {
>>                 for(j = 0, tmpResult = 0.0; j < filterSize; j++)
>>                         tmpResult += originalValues[i + j];
>>                 smoothedValues[i] = tmpResult / (double)filterSize;
>>         }
>> }
> 
> 
> def SmoothedList(originalValues, smoothedValues, listSize, filterSize)
>     iterations  =  listSize - filterSize + 1;
>     for i in range(0,iterations):
>         tmpResult = 0.0
>         for j in range(0, filterSize):
>             tmpResult  =  tmpResult + originalValues[i + j]
>             smoothedValues[i] = tmpResult / filterSize
> 
> ------------------------------------
> Have I missed something here?





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