// average of 4 nearest neighbors
//
R1C1:R5C5 = { (R[]C[-1] + R[]C[+1] + R[-1]C[] + R[+1]C[])/4 };
//
fill r0c0:r0c6 1, 0;  // boundary conditions,
fill r1c0:r6c0 1, 0;  //  1's top and left
fill r1c6:r6c6 0, 0;  //  0's right and bottom
fill r6c1:r6c5 0, 0;
//
format "%6.4f"; format RC;