On Sun, 28 Jan 2018, p...@philipsmith.ca wrote:
I have a data set with quarterly time series for several variables. The time index is recorded in column 1 of the dataframe as a character vector "Q1 1961", "Q2 1961","Q3 1961", "Q4 1961", "Q1 1962", etc. I want to produce line plots with ggplot2, but it seems I need to convert the time index from character to date class. Is that right? If so, how do I make the conversion?
You can use the yearqtr class in the zoo package, converting with as.yearqtr(..., format = "Q%q %Y"). zoo also provides an autoplot() method for ggplot2-based time series visualizations. See ?autoplot.zoo for various examples.
## example data similar to your description d <- data.frame(sin = sin(1:8), cos = cos(1:8)) d$time <- c("Q1 1961", "Q2 1961", "Q3 1961", "Q4 1961", "Q1 1962", "Q2 1962", "Q3 1962", "Q4 1962") ## convert to zoo series library("zoo") z <- zoo(as.matrix(d[, 1:2]), as.yearqtr(d$time, "Q%q %Y")) ## ggplot2 display library("ggplot2") autoplot(z) ## with nicer axis scaling autoplot(z) + scale_x_yearqtr() ## some variations autoplot(z, facets = Series ~ .) + scale_x_yearqtr() + geom_point() autoplot(z, facets = NULL) + scale_x_yearqtr() + geom_point()
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______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.