I want to be able to define the fill= as one of the arguments in a function. First, here is what my tibble looks like:

> x
# A tibble: 16 × 6
   popA  popB  genome   chr1    chr2    chr3
   <chr> <chr>  <dbl>  <dbl>   <dbl>   <dbl>
 1 CG    GOE   0.0165 0.0128 0.0176  0.0176 
 2 CG    SC    0.0173 0.0159 0.0171  0.0184 
 3 DEL   SC    0.0180 0.0150 0.0164  0.0218 
 4 DEL   GOE   0.0165 0.0168 0.0148  0.0183 
 5 GOE   HPK   0.0381 0.0425 0.0340  0.0399 
 6 HPK   KPA   0.0166 0.0192 0.0160  0.0156 
 7 HPK   SC    0.0383 0.0411 0.0348  0.0405 
 8 HPK   WAI   0.0121 0.0133 0.0113  0.0123 
 9 CG    KPA   0.0361 0.0359 0.0361  0.0363 
10 DEL   KPA   0.0322 0.0314 0.0318  0.0332 
11 KPA   LIH   0.0150 0.0160 0.0150  0.0143 
12 GOE   LIH   0.0395 0.0429 0.0360  0.0413 
13 LIH   SC    0.0349 0.0363 0.0327  0.0365 
14 LIH   WAI   0.0105 0.0132 0.00978 0.00954
15 CG    WAI   0.0234 0.0224 0.0219  0.0258 
16 DEL   WAI   0.0209 0.0182 0.0188  0.0252 

And I’d like to have a function where I can define geom_tile(aes(fill=region)) (see function below), but that does not seem to be working. The function:

xfn <- function(df, region){
    df %>%
    ggplot(aes(x = popA, y = popB)) +
    geom_tile(aes(fill=region)) +
    coord_equal() +
    xlab("Sample") +
    ylab("Sample")
}

However, if I try to run it like this: xfn(x, chr1), I get the following error:

Error in `geom_tile()`:
! Problem while computing aesthetics.
ℹ Error occurred in the 1st layer.
Caused by error:
! object 'chr1' not found

I can take the “region” argument out of the function (i.e., explicitly specify fill= in the function), and it works. Like this:

xfn <- function(df){
    df %>%
    ggplot(aes(x = popA, y = popB)) +
    geom_tile(aes(fill=chr1)) +
    coord_equal() +
    xlab("Sample") +
    ylab("Sample")
}

xfn(x) #This produces the plot that I want

So what gives…? Is there a way to make the first function functional?

Sorry if there is an obvious answer, or this is a redundant question with another post I didn’t see, but I did a lot of Googling and tinkering (to no avail) before posting here.

Thanks in advance!