grapes-plus-na-grapes: %+na%

In iembry-USGS/ie2misc: Irucka Embry's Miscellaneous USGS Functions

Description

This function "defines a dyadic operator that will behave differently than the "+" operator with regards to missing values". (Quote by 42- in Source 1 below). In this case, add x and y so that NA is ignored when x is a number and x = NA when x = 0.

Usage

x %+na% y

Arguments

x	numeric vector that does not contain any NA values
y	numeric vector which contains at least one NA value

Value

numeric vector resulting from the sum of x and y

Source

1. Using ':=' in data.table to sum the values of two columns in R, ignoring NAs - Stack Overflow answered by 42- on Oct 28 2012. See http://stackoverflow.com/questions/13106645/using-in-data-table-to-sum-the-values-of-two-columns-in-r-ignoring-nas.

2. R - merge unequal regular (15 min intervals) and irregular time series within 10 minutes - Stack Overflow asked by iembry on Jan 12 2015 and edited by iembry on Feb 2 2015. See http://stackoverflow.com/questions/27930548/r-data-table-dyadic-operator-and-summing-duplicate-rows-based-on-time-se.

Examples

library(ie2misc)
a <- 1:10
b <- c(98:106, NA)

a %+na% b

# Note that if the vector with the NA value(s) is first, then the additive
# result will still be an NA value(s)
b %+na% a


a1 <- 1:12
b1 <- c(98:106, rep(NA, 3))

a1 %+na% b1


# using a matrix of the numeric vectors a and b
mat1 <- matrix(data = c(a, b), nrow = length(b), ncol = 2, byrow = FALSE,
        dimnames = list(c(rep("", length(b))), c("a", "b")))
mat1[, 1] %+na% mat1[, 2]


# using a data.frame of the numeric vectors a and b
df1 <- data.frame(a, b)
df1[, 1] %+na% df1[, 2]


# using a data.table of the numeric vectors a and b
df2 <- data.table(a, b)
df2[, 1, with = FALSE][[1]] %+na% df2[, 2, with = FALSE][[1]]

iembry-USGS/ie2misc documentation built on May 18, 2019, 3:40 a.m.