Date format for subset of ticks on time axis

ggplot2, graph, plot, r, timestamp

Solution

You can use your custom formater for labels also using `breaks="1 day"` argument, you just have to use `function(x)` after `labels=` and `replace myDate$timestamp` with `x`. This will also solve the third problem.

 + scale_x_date(breaks="1 day", 
      labels= function(x) paste(substr(format(x, "%a"),1,1),format(x, "%d"),sep="\n"))

Or you can make your transformation as seperate function and then use it for `labels=`.

my_date_trans<-function(x) {
      paste(substr(format(x, "%a"),1,1),format(x, "%d"),sep="\n")
}

+ scale_x_date(breaks="1 day",labels=my_date_trans)

To change colors for labels you should use `theme()` and `axis.text.x=`. Here I using vector of colors that contains 6 time black and then red as your scale starts with Monday. Those colors are then repeated.

ggplot() +
      geom_rect(data=rects, aes(xmin=saturdays, xmax=sundays,ymin=-Inf, ymax=Inf), alpha=0.1) +
      geom_line(data=myData, aes(x=timestamp, y=value, colour=variable,size=1)) + 
      geom_point(data=myData, aes(x=timestamp, y=value, colour=variable,size=2)) +
      scale_x_date(breaks="1 day",labels=my_date_trans)+
      scale_size_continuous(range = c(1.5,5), guide=FALSE)+
      theme(axis.text.x=element_text(color=c(rep("black",6),"red")))

Problem

Problem I would like to format my X-axis (time) so that the weekends are clearly visible. I would like to display the date as well as the day of the week. Current situation I do this with (full code below) ``` scale_x_date(breaks=myData$timestamp, labels=paste( substr(format(myData$timestamp, "%a"),1,1), format(myData$timestamp, "%d"), sep="\n") ) ``` which gives me Wanted situation I would rather have a one letter abbreviation for the weekdays since it became a bit tight there.. Also, I'd like to color sundays (and holidays really) in red. Here's what I mean (made with GIMP). Note how the first Monday and last Friday was added by using ``` scale_x_date(breaks = "1 day", minor_breaks = "1 days", labels = date_format("%a\n%d"), name="") ``` However, then I get a three letter abbreviation of the weekdays, which I removed in GIMP. Here is the complete code for this example. ``` library(ggplot2) library(scales) library(reshape2) minimumTime <- as.Date("2014-07-01") maximumTime <- as.Date("2014-07-31") x <- seq(minimumTime,maximumTime, by="1 day") y1 <- sin(as.numeric(x)/3) y2 <- cos(as.numeric(x)/3) myData <- data.frame(timestamp=x, y1=y1, y2=y2) myData <- melt(myData, id.vars="timestamp") rects <- data.frame(saturdays=myData[weekdays(myData$timestamp) == "Saturday","timestamp"]-0.5, sundays = myData[weekdays(myData$timestamp) == "Saturday","timestamp"]+1.5) myPlot <- ggplot() + geom_rect(data=rects, aes(xmin=saturdays, xmax=sundays,ymin=-Inf, ymax=Inf), alpha=0.1) + geom_line(data=myData, aes(x=timestamp, y=value, colour=variable,size=1)) + geom_point(data=myData, aes(x=timestamp, y=value, colour=variable,size=2)) + scale_x_date(breaks=myData$timestamp, labels=paste(substr(format(myData$timestamp, "%a"),1,1),format(myData$timestamp, "%d"),sep="\n")) + #scale_x_date(breaks = "1 day", minor_breaks = "1 days", labels = date_format("%a\n%d"), name="") + scale_size_continuous(range = c(1.5,5), guide=FALSE) ``` So to sum up: - Is there a way to color specific breaks in another color? - Is there a way change to the labels manually and still have them for the Monday and the Friday at the beginning and the end in this case? - Also, if there's a way to have the lines of each label centered, that would be awesome :) Thank you!

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