ggplot2 colour function isn't working

[Ali_T]

This is my code:

ggplot(data = covid, aes(x=`medinc1317`+1,y=`population`+1))+
  geom_point()+
  scale_x_log10("Median Income", breaks=c(1,30001,60001,90001,120001), labels=c("0","30000","60000","90000","120000"))+ 
  scale_y_log10("County Population",breaks=c(1,1001,10001,100001,1000001), labels=c("0","1000","10000","100000","1000000"))+
  ggtitle("Covid-19 Cases as a Proportion of County Population vs Median Income")

I'm trying to colour the data for the x axis and y axis different colours, but the colour function isn't doing anything (doesn't even pop up!). Any help would be appreciated.

[FJCC]

Are you trying to color the axis lines and labels? I would do that like this:

DF <- data.frame(Xval = 1:5, Yval = 1:5)
library(ggplot2)
ggplot(DF, aes(Xval, Yval)) + geom_point() + 
  theme(axis.line.x = element_line(color = "green"),
        axis.text.x = element_text(color = "green"),
        axis.line.y = element_line(color = "red"),
        axis.text.y = element_text(color = "red"))

[ries9112]

Not sure what you mean by:

I'm trying to colour the data for the x axis and y axis different colours

Your data points can't be colored differently for the x-axis and the y-axis because each point lies somewhere along both axis.

You would usually pick a categorical variable in your data to which to color the different points by. You can add the column as an argument in aes(colour=variable) or you can add it in geom_point(aes(colour=variable)).

Happy to help more if you could clarify on what you meant there!

[Ali_T]

Thanks! I’m trying to use the “colour” function, but when I type it in only the “colours” function pops up. Not sure what to do.

[ries9112]

Hmm that's weird, I'm actually seeing the same on my end, not sure why the option isn't showing up and I agree it should. You can still add it into aes() regardless, here is an example:

# Making a 2 row example dataframe to use for a simple ggplot
example_data <- data.frame(x=c(1,2), y=c(2,3), color_column=c('text1', 'text2'))
# See below on where to place `colour=`
ggplot(example_data, aes(x = x, y = y, colour = color_column)) + geom_point(aes())

And you should see a chart that looks like this:

Try to see where I placed colour=c and try to replicate that for your data.

You can also wrap it in geom_point(aes()) like this:

ggplot(example_data, aes(x = x, y = y)) + geom_point(aes(colour = color_column))

Which gives the same result.

Let me know if this doesn't get you all the way there and I'd be happy to help! If you need more help I would also recommend looking at "Scenario 2" from this link on how you can give us an example from your data to work with: https://reprex.tidyverse.org/articles/articles/datapasta-reprex.html

[joels]

colour is actually an argument to the aes function rather than a function itself. However, because it's an optional argument, when you type aes( and then type tab, this is what appears:

The ... argument is the stand-in for the optional arguments that can be passed to aes.

Normally, with ggplot you would map a data column to the colour argument, as @ries9112 showed in his answer. Occasionally, you might want to create a colour aesthetic without using a data column, as shown, for example, in this StackOverflow answer.