Error using if clause with yearmon data

Question

library(zoo)
library(lubridate)
yearmon <- as.yearmon(c("01-10", "02-15", "03-30"), "%m-%y")
for (i in yearmon) {
if (year(yearmon[i]) > 2020) {
year(yearmon[i]) <- year(yearmon[i]) - 100
}}

Error in if (year(yearmona[i]) > 2020) { : 
missing value where TRUE/FALSE needed

The idea is to take data with incorrect years > 2020, and put them back to 19XX form.

I think it is not a good idea to use function names (`yearmon`) as variable names. — Karsten W., Oct 16 '17 at 11:22

score 1 · Accepted Answer · answered Oct 16 '17 at 11:14

1

Here, we can use an ifelse and also the assignment part won't work

as.yearmon(paste(format(yearmon, "%b"), 
     ifelse(year(yearmon) > 2020, year(yearmon)-100, year(yearmon))))
#[1] "Jan 2010" "Feb 2015" "Mar 1930"

answered Oct 16 '17 at 11:14

akrun

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`yearmon` objects are numeric year.fractional, so you don't need the `year` function. Simply: `yearmon[yearmon>2020] = yearmon[yearmon>2020]-100` will do the trick. – Spacedman Oct 16 '17 at 11:27
@Spacedman Ya, there are ways, but I was just using the OP's code to correct it – akrun Oct 16 '17 at 11:28
1

This code is a mess. This is not my first attempt at getting these data sets in order... thanks for the assistance. – Albatrosspro Oct 16 '17 at 11:40
1

`ym0 <- as.yearmon(x, "%m-%y"); ym <- ym0 - 100*(ym0 > 2020)` – G. Grothendieck Oct 16 '17 at 14:04

score 1 · Answer 2 · answered Oct 16 '17 at 17:38

Zoo's yearmon objects are year + fractional year, so you subtract 100 from anything over 2020:

> yearmon <- as.yearmon(c("01-10", "02-15", "03-30"), "%m-%y")
> yearmon
[1] "Jan 2010" "Feb 2015" "Mar 2030"
> yearmon[yearmon > 2020] = yearmon[yearmon > 2020] - 100
> yearmon
[1] "Jan 2010" "Feb 2015" "Mar 1930"

this doesn't require lubridate, or any format conversion etc.

Error using if clause with yearmon data

2 Answers2