function coordsArray( N, rTail ) {
	var X;
	var f;
	var i;

	f = exp( -0.5 * rTail * rTail );

	X = [];
	X.push( V/f ); // bottom block: V / f(R)
	X.push( rTail );
	for ( i = 2; i < N; i++ ) {
		X[ i ] = sqrt( -2.0 * ln( ( V/X[i-1] ) + f ) );
		f = exp( -0.5 * X[ i ] * X[ i ] );
	}
	X.push( 0.0 );
	return X;
}
Returns an array containing coordinates such that each rectangle has the same area.

@private
@param {PositiveInteger} N - number of rectangles
@param {number} rTail - start of right tail
@returns {NumberArray} coordinate array

@example
var X = coordsArray( 128, 3.44 );
// returns <Array>