Your DATE
column may represent a date, but it is actually either a character, factor, integer, or a numeric vector.
First, you need to convert the DATE
column to a Date
object. Then you can create an xts object from the CLOSE
and DATE
columns of your PRICE
data.frame. Finally, you can use the xts object to calculate returns and the Calmar ratio.
PRICE <- structure(list(
DATE = c(20070103L, 20070104L, 20070105L, 20070108L, 20070109L,
20070110L, 20070111L, 20070112L, 20070115L),
CLOSE = c(54.7, 54.77, 55.12, 54.87, 54.86, 54.27, 54.77, 55.36, 55.76)),
.Names = c("DATE", "CLOSE"), class = "data.frame",
row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9"))
library(PerformanceAnalytics) # loads/attaches xts
# Convert DATE to Date class
PRICE$DATE <- as.Date(as.character(PRICE$DATE),format="%Y%m%d")
# create xts object
x <- xts(PRICE$CLOSE,PRICE$DATE)
CalmarRatio(Return.calculate(x))
# [,1]
# Calmar Ratio 52.82026