function datasets( N, M, seed ) {
	var data;
	var rand;
	var tmp;
	var i;
	var j;

	rand = randu.factory({
		'seed': seed || ( randu()*pow( 2.0, 31 ) )|0
	});

	// Generate datasets consisting of (x,y) pairs of varying value ranges...
	data = new Array( N );
	for ( i = 0; i < N; i++ ) {
		tmp = new Array( M );
		for ( j = 0; j < M; j++ ) {
			tmp[ j ] = [
				rand() * pow( 10.0, i ),
				rand() * pow( 10.0, i )
			];
		}
		data[ i ] = tmp;
	}
	return data;
}
Generates a set of sample datasets.

@private
@param {PositiveInteger} N - number of datasets
@param {PositiveInteger} M - dataset length
@param {PositiveInteger} [seed] - PRNG seed
@returns {ArrayArray} sample datasets