Help With Vector Conversion

[gh24]

Hi Guys,

I have a variable of the form vector<double> with unknown size.

I need convert this into the form of X1, X2, X3,...,Xn

where Xn is the double value of the vector with position n in the array.

What's the best way to do this? Is it possible even?

[ultifinitus]

When you say convert into the form of, what exactly do you mean?

[firedraco]

Well, you could make an array, but that's redundant and not really useful. Just use theVector[n].

You can't do this with "normal" variables since the size is unknown and I still wouldn't recommend it.

[gh24]

I need to input the vector into a function in the form of x1, x2, .. , xn so that I can run an lpsolve but I can't figure out how to do this. I can't put it in as a vector, It needs to be in that form with the commas separating the terms. I don't know how to make it this way though. I was thinking make it a string of characters but I don't know how to do that either.

[gh24]

I've been trying stuff like this:

{	
		for(i=0; i < P.size()-1; i++){
		double row[] = {DurationVector[i],}; 
		
	
		add_constraint(lp,row, LE, P[P.size()-1][1]);

	}

Where DurationVector is an array of doubles that I need to be put into this function as that same array separated by commas.

[ultifinitus]

you can use a vector just like you do an array, as an array is just a pointer. Just use &vector[0] =]

[gh24]

What do you mean just use &vector[0]? I already have it as an array/vector, I need to have it with the commas separating the values...

[gh24]

I built the vector using the push_back from separate Duration values. I was thinking their may be a way to create a string/char in the same way where I push the value then the comma then another value so on and so forth.

[ultifinitus]

I need to have it with the commas separating the values...

ehrm I doubt you do.... but I'll dig. Why do you need comma separated values? Are you saying the function has comma separated arguments? What does the function do? Is there a better alternative?

In your example you're attempting to convert to an array, which is unnecessary! Just do this!:

add_constraint(lp,&DurationVector[0], LE, P[P.size()-1][1]);

[gh24]

Ill try it now.

From what I have gathered (through trial and error using working programs) I do need comma separated values but I never thought to try to just put it in the add_constraint like that so here goes...

[gh24]

You're amazing...

It worked splendidly. I have been trying to figure this out for five days in a row... it was so simple. Thank you so much for your help.

[ultifinitus]

I do need comma separated values

That's just initializing the array, if you want a new array with the elements of a vector here's a quick (and dirty) and easy way to do it. (you can also just use a pointer...which is exactly what I'm recommending with the &DurationVector[0] thing)

double* row = new double[DurationVector.size()];

for (int a = 0; a < DurationVector.size(); a++){
row[a]=DurationVector[a];
}

//do your stuff with row here

delete [] row;