Decomposes a positive integer into its constituent prime powers (I. Wakeling & R.W. Payne).
Option
PRINT = string token |
Controls printed output (decomposition); default * |
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Parameters
NUMBER = scalars |
Number to be decomposed |
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PRIMES = pointers |
Prime factors of NUMBER |
POWERS = pointers |
Powers of the prime factors in NUMBER |
Description
Procedure PRIMEPOWER decomposes the integer specified by the NUMBER parameter into its constituent prime powers. The results can be saved using the PRIMES and POWERS parameters. These return pointers to a set of scalars storing, respectively, the relevant prime numbers and their powers. If NUMBER is not a positive integer, the pointers will each contain a single scalar containing a missing value. The decomposition can also be printed by setting option PRINT=decomposition.
Option: PRINT.
Parameters: NUMBER, PRIMES, POWERS.
Method
PRIMEPOWER uses the standard Genstat calculation directives.
See also
Procedure: NCONVERT.
Commands for: Calculations and manipulation.
Example
CAPTION 'PRIMEPOWER example'; STYLE=meta " a single prime " PRIMEPOWER [PRINT=decomposition] 17; PRIMES=p; POWERS=n " powers of a single prime " PRIMEPOWER [PRINT=decomposition] 8; PRIMES=p; POWERS=n " powers of several primes " PRIMEPOWER [PRINT=decomposition] 12; PRIMES=p; POWERS=n PRINT p[],n[]; DECIMALS=0