RosettaCodeData/Task/Averages-Simple-moving-average/R/averages-simple-moving-average.r
2023-07-01 13:44:08 -04:00

31 lines
956 B
R

#concat concatenates the new values to the existing vector of values, then discards any values that are too old.
lastvalues <- local(
{
values <- c();
function(x, len)
{
values <<- c(values, x);
lenv <- length(values);
if(lenv > len) values <<- values[(len-lenv):-1]
values
}
})
#moving.average accepts a numeric scalars input (and optionally a length, i.e. the number of values to retain) and calculates the stateful moving average.
moving.average <- function(latestvalue, len=3)
{
#Check that all inputs are numeric scalars
is.numeric.scalar <- function(x) is.numeric(x) && length(x)==1L
if(!is.numeric.scalar(latestvalue) || !is.numeric.scalar(len))
{
stop("all arguments must be numeric scalars")
}
#Calculate mean of variables so far
mean(lastvalues(latestvalue, len))
}
moving.average(5) # 5
moving.average(1) # 3
moving.average(-3) # 1
moving.average(8) # 2
moving.average(7) # 4