Having trouble making a 2 Y axis in RMarkdown

[Argyris_Venidis]

I am trying to create a 2 y axis graphs, corresponding to the Maximum and Minimum depth and temperature that a marine organism did during one time

period
This is the best graph that I managed to do so far, but I have trouble into rescaling the Y axes for both for better visualization. For the Temperature axis I am trying to make it to10 to 20, instead of the -20, -10, 0, 10, 20 and for the Depth axis to 0 to 30.

ggplot(Sharks1, aes(x = Date)) +
 geom_line(aes(y = Depth, color = Min_Max.x)) +
 geom_line(aes(y = Temp, color = Min_Max.y)) +
 scale_y_continuous(
   sec.axis = sec_axis(~ -., name = "Depth (m)")
 ) +
 labs(y = "Temperature (°C)", color = NULL) +
 theme_minimal()

This is currently my code, any help would be appreciated

[M_AcostaCH]

Hi @Argyris_Venidis, try to put a reproducible example of data.

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…

So, see this information avoiding-the-dual-axis-chart

Maybe is better make 2 plot because de values of Temperature are all positives and Depth are < 0, for avoiding confusion in the interpretation.

[jrkrideau]

I second M_AcostaCH suggestion not to use a dual y-axis chart. They are very hard to interpret.

Here is a really quick and dirty example of using two plots and putting them together with the {patchwork} package.

set.seed(1913)
dat1  <- data.frame(date1 = seq(as.Date("2023/10/01"), as.Date("2023/10/31"), by = "day"),
                  aa = rnorm(31, mean = 0, sd = 1), bb = rnorm(31, mean = 5, sd = 2))


p1 <- ggplot(dat1, aes(date1, aa)) + geom_point(colour = "red") +
       geom_line(colour = "blue")
p2 <- ggplot(dat1, aes(date1, bb)) + geom_point(colour = "blue") +
        geom_line(colour = "red")

p1 / p2

# or
 p1 + p2