c to c# help

[tinkerz]

I dont understand some of this code I am trying to convert

Can anyone help?

void movingAverage(float * data, int windowSize) 
// what does the * do?

 {
float s1=0;
int i;
for (i=windowSize;i>0;i--)
{
s1 = s1 + *(data-i)/windowSize;
//printf(" %f\n",*(data-i));
}
*(data) = s1;

// and how does this * work?

//printf(" %f\n",*data);
}



while(*(data+count)-meanSd > Tol || *(data+count)-meanSd < (-1.0)*Tol ) 
// what does the * before data do?

sdData = (float *)malloc(100000*sizeof(float));//
// what is (float *)

[NinjaTrader_JC]

Hello tinkerz,

The asterisk in this sample refers to a "pointer" inside of the "C" code. While this is not something we can support there is some examples that you may view to try to help you understand this.

http://www.codeproject.com/Articles/627/A-Beginner-s-Guide-to-Pointers

http://www.codeproject.com/Articles/4894/Pointer-to-Pointer-and-Reference-to-Pointer

[BigWaveDave]

Yes these snippets look a little bit disjointed.

It looks like what is being passed in is a pointer to a chunk of memory containing floats (of size WindowSize which is total number of floats that will fit in the chunk of memory)

C# doesn't support pointer syntax or pointers (which are really just memory addresses)

The first snippet then fills up each float in the chunk of memory with a value.

If I were you , I would just convert the allocated block into a collection such as a List<float> or ArrayList<float>. You can then just pass the list around and do whatever processing you need to do on it.

// what does the * before data do?

That * 'dereferences the address within the (). So what's within the () specifies which float location within the allocated block to look at the contents of.. then it subtracts a value from that float. Again, you can do the same with a collection class. Instead of float thefloat = *(data-somenumber)-othernumber;
you could do something like:
float thefloat = myfloatarray[theIndex]-othernumber;

The second snippet allocates a 100000 floats in one shot... you can do the same thing with one of the collection classes.

Anyway, hope that doesn't confuse you more.