prod                  package:base                  R Documentation

Product of Vector Elements

Description:

     'prod' returns the product of all the values present in its
     arguments.

Usage:

     prod(..., na.rm = FALSE)

Arguments:

     ...: numeric or complex or logical vectors.

   na.rm: logical.  Should missing values be removed?

Details:

     If 'na.rm' is 'FALSE' an 'NA' value in any of the arguments will
     cause a value of 'NA' to be returned, otherwise 'NA' values are
     ignored.

     This is a generic function: methods can be defined for it directly
     or via the 'Summary' group generic. For this to work properly, the
     arguments '...' should be unnamed, and dispatch is on the first
     argument.

     Logical true values are regarded as one, false values as zero. For
     historical reasons, 'NULL' is accepted and treated as if it were
     'numeric(0)'.

Value:

     The product, a numeric (of type '"double"') or complex vector of
     length one. *NB:* the product of an empty set is one, by
     definition.

S4 methods:

     This is part of the S4 'Summary' group generic.  Methods for it
     must use the signature 'x, ..., na.rm'.

References:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

See Also:

     'sum', 'cumprod', 'cumsum'.

     'plotmath' for the use of 'prod' in plot annotation.

Examples:

     print(prod(1:7)) == print(gamma(8))

