withNullFill

withNullFill(func, x, y, fillValue)

func is a DolphinDB built-in function with two inputs, such as +, -, *, /, \, %, pow, and, or, etc.

x and y are vectors or matrices.

fillValue is a scalar.

If only 1 of the elements at the same location of x and y is NULL, replace the NULL value with fillValue in the calculation. If both elements at the same location of x and y are NULL, return NULL.

x = 0 1 NULL NULL 2
y = 1 NULL 2 NULL 3;
add(x,y);
// output
[1,,,,5]

withNullFill(add, x, y, 0);
// output
[1,1,2,,5]

m=matrix(1..5, y);
m;

add(x, m);

withNullFill(add, x, m, 0);