Sum of digits of an integer
This functionality does not run in MATLAB.
numlib::sumOfDigits(n, base) computes the sum of digits of n in the given base base); if the base is not given, it defaults to 10.
The sum of digits may be larger than the base. For certain purposes (testing divisibility by b - 1, where b is the base), it may be useful to apply numlib::sumOfDigits over and over to the result. This is not done automatically. See Example 2.
We compute the decimal and the binary sum of digits of 11:
numlib::sumOfDigits(11), numlib::sumOfDigits(11, 2)
We want to test whether 9 divides a given number, using the school method:
n:= 24373463462374324: repeat n:= numlib::sumOfDigits(n); print(n) until n < 10 end: delete n:
This only makes sense for demonstration purposes, as the following command achieves the same but much faster:
24373463462374324 mod 9