qreal Statistics::correlationCoefficient(const Vector &X, const Vector &Y)
{
Vector Xc = centeredRandomVariables(X);
Vector Yc = centeredRandomVariables(Y);
qreal Dx = sumOfSquares(Xc);
qreal Dy = sumOfSquares(Yc);
qreal rxy = 0.0;
for (qint32 i = 0; i < X.count(); ++i)
rxy += Xc.at(i)*Yc.at(i);
return rxy/qPow(Dx*Dy, 0.5);
}
int main()
{
long difference;
difference = squareOfSum(LIMIT) - sumOfSquares(LIMIT);
printf("The difference is: %ld\n", difference);
return 0;
}
int main(void)
{
int result = squareOfSum(100) - sumOfSquares(100);
printf("%d\n", result);
return result;
// Answer: 25164150
}
int main(){
int sum_square, square_sum, difference;
sum_square = sumOfSquares();
square_sum = squareOfSums();
difference = square_sum - sum_square;
printf("%d\n", difference);
return 0;
}
int main(void) {
// sum the diagonals of a 1001x1001 spiral
// excluding the first 1 each level has a box with 4 corners
// c4 => (2x + 1)^2 - 0x
// c3 => (2x + 1)^2 - 2x
// c2 => (2x + 1)^2 - 4x
// c1 => (2x + 1)^2 - 6x
// avg => (2x +1)^2 - 3x
// => 4x^2 + x + 1
// each level sum is 4(4x^2 + x + 1)
// There are 500 levels plus the first 1
uint64_t result = 1;
result += 4 * 500;
result += 4 * sumOfNumbers(500);
result += 16 * sumOfSquares(500);
std::cout << result << std::endl;
}
/** Test matrix classes */
int main()
{
hilbert();
submatrix();
sumOfSquares();
indexDenseSubmatrix();
spGetCol();
spGetRow();
spTimes();
spIndTimes();
sprGetCol();
sprGetRow();
sprTimes();
sprIndTimes();
Symmetry();
return 0;
}
int
main()
{
printf("%lu\n", squareOfSum(NUM) - sumOfSquares(NUM));
return 0;
}
int main()
{
printf("%lld\n", squareOfSums(100) - sumOfSquares(100));
return 0;
}
int64_t squaresDiff(int64_t n){return squareOfSum(n)-sumOfSquares(n);}
qreal Statistics::variance(const Vector &X)
{
Vector Xc = centeredRandomVariables(X);
qreal Dx = sumOfSquares(Xc);
return Dx /= (X.count() - 1);
}
