Question

How can one assign values to a 2D array on stack memory. I tried the following, which doesn’t seem to work. Of course one can assign each value at a time, but I was interested in assigning the values in one go. Any ideas?

double phi[2][5];
phi[0] = {1, 0, 2, 1, 0};
phi[1] = {1, 0, 2, 1, 0};

Answer 1

You can initialise the array:

double phi[2][5] = { {1, 0, 2, 1, 0 },
                     {1, 0, 2, 1, 0 } };

Note omitted elements will default to zero so the following would produce the same result:

double phi[2][5] = { {1, 0, 2, 1 },
                     {1, 0, 2, 1 } };

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If the compiler supports C99 then compound literals could be an option but the type of phi would need to change to a pointer to an array of double[5]. For example:

double (*phi)[5];

phi = (double[][5]) { { 11, 12, 13, 14, 15 },
                      { 21, 22, 23, 24, 25 } };

phi = (double[][5]) { { 111, 122, 133, 144, 155 },
                      { 211, 222, 233, 244, 255 } };

But all dimensions must be assigned, not individual dimensions (see demo http://ideone.com/NxdUO ).