PercChange: Calculate the percentage change from a specified lag,...

Description Usage Arguments Details Value Examples

View source: R/PercChange.R

Description

Calculate the percentage change from a specified lag, including within groups

Usage

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PercChange(data, Var, GroupVar, NewVar, slideBy = -1, type = "percent", ...)

Arguments

data

a data frame object.

Var

a character string naming the variable you would like to find the percentage change for.

GroupVar

a character string naming the variable grouping the units within which the percentage change will be found for (i.e. countries in a time series). If GroupVar is missing then the entire data frame is treated as one unit.

NewVar

a character string specifying the name for the new variable to place the percentage change in.

slideBy

numeric value specifying how many rows (time units) to make the percentage change comparison for. Positive values shift the data up–lead the data.

type

character string set at either percent for percentages or proportion to find proportions.

...

arguments passed to slide.

Details

Finds the percentage or proportion change for over a given time period either within groups of data or the whole data frame. Important: the data must be in time order and, if groups are used, group-time order.

Value

a data frame

Examples

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# Create fake data frame
A <- c(1, 1, 1, 1, 1, 2, 2, 2, 2, 2)
B <- c(1:10)
Data <- data.frame(A, B)

# Find percentage change from two periods before
Out <- PercChange(Data, Var = 'B',
         type = 'proportion',
         NewVar = 'PercentChange',
         slideBy = -2)

Out

Example output

Remember to put data in time order before running.

Lagging B by 2 time units.

Warning message:
PercChange is depricated. Please use change. 
   A  B PercentChange
1  1  1            NA
2  1  2            NA
3  1  3     2.0000000
4  1  4     1.0000000
5  1  5     0.6666667
6  2  6     0.5000000
7  2  7     0.4000000
8  2  8     0.3333333
9  2  9     0.2857143
10 2 10     0.2500000

DataCombine documentation built on May 30, 2017, 2:52 a.m.