FACTORS

Purpose:

Returns the prime factors of a scalar.

FACTORS(ival)

ival

An integer, the value to factor.

A series.

factors(357)

returns the series: {3, 7, 17}.

p = factors(1975);

q = cumprod(p);

r = colreduce(p, "*");

s = prod(p);

p == {5, 5, 79}

q == {5, 25, 1975}

r == {1975}

s == 1975

factors(19)

returns the series: {19}. 19 is a prime number, so there is only one point in the resulting series.

FACTORS is particularly useful in determining whether a series length is prime. The FFT algorithm runs slowest on series with prime lengths.

See PROD to multiply the values of a series and return a scalar.