# period.prod

From xts v0.9-7
0th

Percentile

##### Calculate Product By Period

Calculate a product for each period of INDEX. Essentially a rolling application of prod over a series of non-overlapping sections.

Keywords
utilities
##### Usage
period.prod(x, INDEX)
##### Arguments
x

a univariate data object

INDEX

a vector of breakpoints to calculate product on

##### Details

Used to calculate a product per period given an arbitrary index of sections to be calculated over. This is an optimized function for product. There are additionally optimized versions for min, max, and sum.

For xts-coercible objects, an appropriate INDEX can be derived from a call to endpoints.

##### Value

An xts or zoo object of products, indexed by the period endpoints.

endpoints, period.sum, period.min, period.max
library(xts) # NOT RUN { period.prod(c(1,1,4,2,2,6,7,8,-1,20),c(0,3,5,8,10)) data(sample_matrix) period.prod(sample_matrix[,1],endpoints(sample_matrix)) period.prod(as.xts(sample_matrix)[,1],endpoints(sample_matrix)) # }