Most elegant Qt Multidimentional array

[philwinder]

Hi,
What is the most elegant way of creating a Qt-like multidimentional array since I'm having to mess with:

QList<double> myList[100]

QList<double> myList[100]

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and access it with:

myList[x].at(y)

myList[x].at(y)

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Obviously the x part of the array doesnt benefit from any of Qt's container properties. Any ideas?

[JimDaniel]

QList<QList<double>> ?

double d = myList.at(x).at(y);

[philwinder]

Yep, Ive just got that working. I was having problems with it because I was trying to do this:

for( int x = 0; x < 181; x++ ){
                theList.append(x);
		for( int y = 0; y < 2001; y++ )
			theList.at(x).append(y);
	}

for( int x = 0; x < 181; x++ ){
                theList.append(x);
		for( int y = 0; y < 2001; y++ )
			theList.at(x).append(y);
	}

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When I should have been doing:

QList<double> temp;
	for( int x = 0; x < 181; x++ ){
		temp.clear();
		for( int y = 0; y < 2001; y++ )
			temp.append(y);
		theList.append(temp);
	}

QList<double> temp;
	for( int x = 0; x < 181; x++ ){
		temp.clear();
		for( int y = 0; y < 2001; y++ )
			temp.append(y);
		theList.append(temp);
	}

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Cheers,
Phil

[wysota]

I just came up with a crazy idea to represent a 2D array using a tree or a map:

struct 2DArrayIndex { int x, y; ... };
class 2DArray : public QHash<2DArrayIndex, int> {
 //...
};

struct 2DArrayIndex { int x, y; ... };
class 2DArray : public QHash<2DArrayIndex, int> {
 //...
};

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One would need a custom method to access the data, so that it returned some default value if the item under specified coordinates would not be present, but apart from that we'd have a nice representation of a sparse 2D array. It wouldn't make sense to do it this way with dense arrays though...