Logarithm

x xlog y    xlog[x;y]

Returns the base-xf logarithm of yf, where xf and yf are x and y cast to floats, i.e. "f"$(x;y).

Where yf is negative or zero, the result is null and negative infinity respectively.

q)2 xlog 8
3f

q)2 xlog 0.125
-3f

q)1.5 xlog 0 0.125 1 3 0n
-0w -5.128534 0 2.709511 0n

q)`float$"AC"
65 67f
q)65 xlog 67
1.00726
q)"A"xlog"C"
1.00726