periodic {ggperiodic}

Add or remove periodic variables

Description

Creates a periodic object by specifying the periodic variables and their periods.

Usage

periodic(object, ...)

## Default S3 method:
periodic(object, period, ...)

## S3 method for class 'data.frame'
periodic(object, ...)

setperiodic(object, ...)

Arguments

object

the object to coerce to periodic

...

name-value pairs of expressions defining the period

period

a numeric vector whose range defines the period

Value

An object of subclass periodic_df or periodic_v.

If object is of class data.table, then it will modify the object by reference. To modify this behaviour, use options(ggperiodic.data.table.copy = TRUE). setperiodic() will modify a data.table by reference bypassing the global option.

Examples

library(ggplot2)

x <- seq(0, 360 - 20, by = 20)
df <- data.frame(x = x, y = cos(x*pi/180))
df_p <- periodic(df, x = c(0, 360))

ggplot(df_p, aes(x, y)) +
   geom_line() +            # periodic data
   geom_point(data = df)    # non periodic data

# Extend domain
ggplot(df_p, aes(x, y), x = c(-180, 540)) +
   geom_line() +
   geom_point(data = df)

# with non regular intervals
x <- runif(30, 0, 360)
df <- periodic(data.frame(x = x, y = cos(x*pi/180)),
               x = c(0, 360))
ggplot(df, aes(x, y), x = c(-180, 540)) +
   geom_point()