December 1, 2012
R tutorial: Simple charts

Here’s a (still getting tweaked) R tutorial for the charts in the last post. Here’s the data you’ll need to download.

Set your working directory to wherever you want to work out of (usually a project folder)

setwd("/Users/pathToMyFolder...")

Next, load the data. Any format is fine, but our data is a tab-delimited .txt files, so we can use read.delim (here, my data is in a folder called “data,” but yours can be wherever).

data <- read.delim("data/states-data.txt")

Make a new field in your data frame that is the sum of unified states:

data$total.unified <- data$Unified.D+data$Unified.R

Now our data is ready to chart. It’s just one line of code to make a plot of the number of unified states over time, with “Year” on the x axis and “total.unified” on the Y axis:

plot(data$Year,data$total.unified,type='l',ylim=c(0,50))

shot1

The same plot, with extra arguments to clean it up a little:

plot(data$Year,data$total.unified,type='l',ylim=c(0,50),xlab="Year",ylab="States",main="States with unified control of state government since 1938",col="red",lwd=3) abline(h=c(0,10,20,30,40,50),col='lightgrey') abline(v=c(1940,1960,1980,2000),col='lightgrey')

clean

Adding more layers onto the plot, drawing lines for Democratic- and Republican- unified states. (In general, “plot” makes a chart and “lines” add to an existing plot.)

plot(data$Year,data$Divided,type='l',ylim=c(0,30)) lines(data$Year,data$Unified.R,col="red") lines(data$Year,data$Unified.D,col="blue")

img2

Now we’ll make a barplot instead. The syntax here is a little weird, and I had to get Amanda to fix mine originally, but it’s not so bad. Basically, our data needs to be transposed and reduced to just the columns we want to plot. You can do this in one step, but for clarity I’ll break it up here. It looks like a waffle chart just because of the horizontal axis lines, but it’s just a barplot.

#just the numbers we want to plot data.we.need<-data[,c("Unified.D","Divided","Unified.R")]  #a simple reshaping, transposing our data transposed<-t(data.we.need)  barplot(transposed,ylim=c(0,50),col=c('blue','grey','red'),border=F) abline(h=c(1:50),col='white')

waffle

We end up doing the same plot for the final output; it’s just shaped differently and has fewer axis lines. We’re also saving it as a pdf in the dimensions we want:

pdf(file="stacked-bars.pdf",width=8,height=5) barplot(transposed,ylim=c(0,50),col=c('blue','grey','red')) abline(h=c(10,20,30,40),col='white') dev.off()

img3

Ship that!

4:31pm  |   URL: http://tmblr.co/ZpUrewYS4wQi
  
Filed under: R tutorial 
  1. g0bananas reblogged this from chartsnthings
  2. learnfrominfo reblogged this from chartsnthings and added:
    From simple charts to the NYT.
  3. edomaniac reblogged this from chartsnthings
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  5. babydatajournalism reblogged this from jour72312
  6. jour72312 reblogged this from chartsnthings and added:
    I’ll keep saying this, I bet:...fine tuning visual encoding.
  7. immaculatellamalord reblogged this from onaissues
  8. onaissues reblogged this from chartsnthings and added:
    Kevin Quealy, graphics editor at...New York Times, gave
  9. lifeandcode reblogged this from chartsnthings and added:
    YESSSSSSSSS
  10. blairtheblur reblogged this from chartsnthings and added:
    don’t have enough things...do, I’m trying
  11. chartsnthings posted this