⍟ Log to the base

Two-argument form  See also one-argument form Natural Logarithm

Computes the log of a number or numbers to an arbitrary base. The left-hand argument is the base and the right-hand argument is the number whose log is to be found.

             3 ⍟ 9                   (The log of 9 to the base 3)
       2
             2 3 4 5 6⍟4 9 16 25 36  (The log of each number on the right to
       2 2 2 2 2                      the corresponding base on the left)
             2 ⍟ 2 4 8 16 32 64
       1 2 3 4 5 6
             2 ⍟ 13.9
       3.797012978
             2 3⍟(2 2⍴2 4 8 16) (3 9 27)
       1 2  1 2 3
       3 4                            (Corresponding elements of left and right
                                      arguments used as successive arguments to
                                      the ⍟ function)