Arrays.java

// Find the maximum of the array values

double max = a[0];
for (int i = 1; i < a.length; i++)
if (a[i] > max) max = a[i];


// Compute the average of the array values

int N = a.length;
double sum = 0.0;
for (int i = 0; i < N; i++)
  sum += a[i];
double average = sum / N;


// Copy to another array

int N = a.length;
double[] b = new double[N];
for (int i = 0; i < N; i++)
  b[i] = a[i];


// Reverse the elements within an array

int N = a.length;
for (int i = 0; i < N/2; i++)
{
  double temp = a[i];
  a[i] = a[N-1-i];
  a[N-i-1] = temp;
}


// Matrix-matrix multiplication (square matrices)
// a[][]*b[][] = c[][]

int N = a.length;
double[][] c = new double[N][N];
for (int i = 0; i < N; i++)
  for (int j = 0; j < N; j++)
  { // Compute dot product of row i and column j.
    for (int k = 0; k < N; k++)
    c[i][j] += a[i][k]*b[k][j];
  }