yulab.utils (version 0.2.0)

initial_cache: cache intermediate data

Description

Yulab provides a set of utilities to cache intermediate data, including initialize the cached item, update cached item and rmove the cached item, etc.

Usage

initial_cache()
get_cache()
rm_cache()
initial_cache_item(item)
get_cache_item(item)
rm_cache_item(item)
update_cache_item(item, elements)
get_cache_element(item, elements)

Value

return the cache environment, item or selected elements, depends on the functions.

Arguments

item

the name of the cached item

elements

elements to be cached in the item

Examples

if (FALSE) {
 slow_fib <- function(x) {
     if (x < 2) return(1)
     slow_fib(x-2) + slow_fib(x-1)
 }
 
 fast_fib <- function(x) {
     if (x < 2) return(1)
     res <- get_cache_element('fibonacci', as.character(x))
     if (!is.null(res)) { 
         return(res)
     }
     res <- fast_fib(x-2) + fast_fib(x-1)
     e <- list()
     e[[as.character(x)]] <- res
     update_cache_item('fibonacci', e)
     return(res)
 }

 system.time(slow_fib(30))
 system.time(fast_fib(30)) 
    
 }