Hi! I'm new to R and am working through the R for Data Science online book. I wanted to try do some data frames of my own and decided to graph some weather data. I would like to show a line graph of the temperature and the barometric pressure to show the relationship between changes in the two. However, the Y domains for the two series are different enough that you can't really see the trend (temps in F are 60-90 range and pressure in millibars are 1000+). I'm only interested in the trend, not the specific Y values. I tried adding a second axis, but that didn't show what I wanted and I also thought maybe if there was a way to do 2 graphs with the X data points aligned vertically it would accomplish the same goal. Does any have any suggestions on the best way to tackle this (again, I'm very new to R so its possible there is an easy solution I haven't read about yet)?
Thanks in advance!
library(ggplot2) library(tidyr) df <- data.frame( ReadingDate = c("2019-08-19", "2019-08-20", "2019-08-21", "2019-08-22", "2019-08-23"), LowP = c(1013.85, 1013.2, 1012.89, 1013.7, 1015.79), HighP = c(1016.53, 1016.73, 1015.86, 1015.45, 1019.11), LowTemp = c(68.3, 68.54, 68.66, 69.49, 62.7), HighTemp = c(86.89, 84.9, 81.43, 77.44, 70.27) ) df %>% gather(key, value, LowP, HighP, LowTemp, HighTemp) %>% ggplot(aes(x=ReadingDate, y=value, color=key, group=key)) + geom_line()
Created on 2019-08-24 by the reprex package (v0.3.0)