dplyrx

dplyrx is a collection of functions that extend those in the dplyr package.

Installation

You can install dplyrx from github with:

# install.packages("devtools")
devtools::install_github("epix-project/dplyrx")

To load the package:

library(dplyrx)

Example

Below is a basic example which shows you how to solve a common problem. Imagine that you have a data frame that looks like this:

set.seed(30101976)
data <- expand.grid(letters[1:3], 1:3, 4:6)
data <- cbind(data, data.frame(replicate(3, sample(1:100, nrow(data), TRUE))))

where Var1 could be thought of a spatial location name, Var2 and Var3 can be thought of year and month and X1, X2 and X3 can be tought of measured values for given points in space and time. If you want to aggregate the values “a” and “b” of the categorical the variable Var1, summing the values of variables X4, X5 and X6, it can be done like this:

data <- transform(data, Var1 =  ifelse(data$Var1 == "a", "b",
                                        as.character(data$Var1)))
aggregate_by(data, Var1, Var2, Var3)
#>    Var1 Var2 Var3 X1  X2  X3
#> 1     b    1    4 46 106 127
#> 7     b    1    5 95  75  50
#> 13    b    1    6 77  28  76
#> 3     b    2    4 37 117 118
#> 9     b    2    5 56 125  89
#> 15    b    2    6 91 150 149
#> 5     b    3    4 99 106 120
#> 11    b    3    5 57 104 142
#> 17    b    3    6 18  49 145
#> 2     c    1    4 42  75  75
#> 8     c    1    5 50  89  40
#> 14    c    1    6  6   4  61
#> 4     c    2    4 75  58  99
#> 10    c    2    5 15  48   9
#> 16    c    2    6 43  33   4
#> 6     c    3    4 30  64  40
#> 12    c    3    5 98  12  92
#> 18    c    3    6 46   4  30