How do I make a simple graph with subset factor and two variables? (help pls)

[jkml]

My data contains the Years of sampling / Site (with 6 different sites)/ and 3 different chemical parameters

I want to create a simple graph with the year on the X and Nitrate on the Y for one site in particular ...

I don't know what code to use, I tried this
plot(Allsites_data$Nitrate~Allsites_data$Year) but it doesn't classify the site I want... Thanks!

[jrkrideau]

Try subsetting the data.

     dat1  <-  subset(Allsites_data, Site == "Brownstown")

Then graph dat1

Rince and repeat for each value of Site
There are other ways and probably better ones but this should work in base R

For future reference, here are some hints on asking questions in the forum.

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.…

[jkml]

Thanks a mil for that!

[timwilson7]

Building on @jkrideau's response a little bit, to get the plot in a single command using base R (plot and subset):

plot(x = subset(Allsites_data$Year, Allsites_data$Site == "Brownstone"),
     y = subset(Allsites_data$Nitrate, Allsites_data$Site == "Brownstone"))

The kicker is this may not give you quite what you want depending on the data type of Year in the data frame (which is one of the reasons a reproducible example is nice to have). If Year is numeric, then you may see things like "2011.5" in the x-axis of a dot plot.

If, instead, Year is a factor, you may get a y-axis that is more what you expected, and you will likely get a boxplot instead of a dot plot.

Depending on what you're looking for, specifically, you may need to do a little bit of light work on the data frame or do some additional formatting work within plot() (or, potentially, consider switching over and using ggplot(), but my sense is that you're not looking to dive into that world).

Good luck!

[jkml]

Thanks so much, really helped !!