Vanadium posted:

T sum = T(); should work in all cases I can think of.

ultra-inquisitor posted:

What about matrices? Mightn't they be constructed to the identity matrix, rather than all zeros? Is there a more standard method which doesn't rely on the implementation of the type?

ultra-inquisitor posted:

What about matrices? Mightn't they be constructed to the identity matrix, rather than all zeros? Is there a more standard method which doesn't rely on the implementation of the type?

The Red Baron posted:

If this is a concern, just provide the initial value as a default parameter

code:

template <typename T>
T sumArray (const vector<T> &arr, T init = T())
{
	for (size_t i = 0; i < arr.size (); ++i)
		init += arr[i];

	return init;
}

Ledneh posted:

The second is the same way, except I count on the rest of the team to use boost::bind where needed. Cleaner and less error-prone for me, and probably more type-safe, but the rest of the group has to learn how (and remember) to use boost::bind.

Ledneh posted:

BigRedDot, I implemented your solution in my test bed, and it works great, but I have one question. I was discussing this elsewhere too, and the question came up as to whether or not for your templated SetCallback you have to include a template parameter.

My compiler (Sun CC) can get away with SetCallback(Type::blah, obj), but someone else reported their compiler giving up until they did SetCallback<Type>(Type::blah, obj). I assume you're supposed to have to specify the template parameter explicitly?

Ledneh posted:

so that I could at least have them together to make it easier to keep synced, but it didn't take, with an error about templated typedefs being an anachronism. Is there anything I can do about this, or am I more or less stuck?

DontMockMySmock posted:

code:

#define nfreq 90
float chisquared(float coef, float index, float pixel[nfreq],float fq[nfreq]){
  float sum=0;
  int i=0;
  for(i=0;i<nfreq;i++) {
    sum=sum+(pow(pixel[i]-coef*pow(fq[i],index),2))/(coef*pow(fq[i],index));
    }
  return sum;
}

Given that all of the input variables are always positive and nonzero, how could this code ever return NaN? Because it does, all the time.
The only thing I could figure was if fq was ever negative and index was a power that would result in imaginary numbers. But fq is (in the main code) read from a file, which contains only positive numbers, and I checked that it read correctly, all positive. What else could cause it to return NaN?
Thanks in advance.

DontMockMySmock posted:

code:

#define nfreq 90
float chisquared(float coef, float index, float pixel[nfreq],float fq[nfreq]){
  float sum=0;
  int i=0;
  for(i=0;i<nfreq;i++) {
    sum=sum+(pow(pixel[i]-coef*pow(fq[i],index),2))/(coef*pow(fq[i],index));
    }
  return sum;
}

Given that all of the input variables are always positive and nonzero, how could this code ever return NaN? Because it does, all the time.
The only thing I could figure was if fq was ever negative and index was a power that would result in imaginary numbers. But fq is (in the main code) read from a file, which contains only positive numbers, and I checked that it read correctly, all positive. What else could cause it to return NaN?
Thanks in advance.

DontMockMySmock posted:

code:

#define nfreq 90
float chisquared(float coef, float index, float pixel[nfreq],float fq[nfreq]){
  float sum=0;
  int i=0;
  for(i=0;i<nfreq;i++) {
    sum=sum+(pow(pixel[i]-coef*pow(fq[i],index),2))/(coef*pow(fq[i],index));
    }
  return sum;
}

Given that all of the input variables are always positive and nonzero, how could this code ever return NaN? Because it does, all the time.
The only thing I could figure was if fq was ever negative and index was a power that would result in imaginary numbers. But fq is (in the main code) read from a file, which contains only positive numbers, and I checked that it read correctly, all positive. What else could cause it to return NaN?
Thanks in advance.

ultra-inquisitor posted:

It's just for my own edification, I was wondering if there was some cool language feature I didn't know about that might facilitate it. I'm still pretty inexperienced at generic programming.

Jo posted:

I'm getting a sigabrt on a delete. I know it's a memory management problem, but I don't see why...

code:

Image * plessyFilter( Image * img, float k = 0.04 ) {
	Image * plessy = new Image( img->getWidth(), img->getHeight() );
	Image * gaussian = runGaussian3x3( img );
	
	// snip!

	delete gaussian;
	return plessy;
}

... the delete fails on the gaussian image. If I use new inside the runGaussian function, it (the blurred image) should NOT be deleted when I return from runGaussian. Why would the data allocated with new disappear on a return?

Jo posted:

I'm getting a sigabrt on a delete. I know it's a memory management problem, but I don't see why...

... the delete fails on the gaussian image. If I use new inside the runGaussian function, it (the blurred image) should NOT be deleted when I return from runGaussian. Why would the data allocated with new disappear on a return?

DamageInc posted:

ultra-inquisitor posted:

Is runGaussian3x3 in a different DLL, or are you using new[] to allocate the memory?

Avenging Dentist posted:

Why wouldn't you just use a smart pointer there?

Otto Skorzeny posted:

If you have valgrind you can check whether you're leaking memory pretty easily (as long as your program doesn't have a long run time as-is).


e: hey put that image back up it was

Vanadium posted:

If you allocate memory with new[], you have to deallocate it with delete[].

schnarf posted:

What does the destructor for Image do? Is it possible that the constructor does something with the pointer to img and then something funky happens in the destructor?