R Heatmap - Change Axes to Variable From Function - r

Question

I'm trying to create a function in R that will take in two names (characters) and two doubles. It will then output a ggplot2 heatmap. Here's the data:
> dput(df)
structure(list(`0` = c(0.0608, 0.0791, 0.0514, 0.0223, 0.0072,
0.0019, 4e-04, 1e-04, 0, 0, 0), `1` = c(0.0912, 0.1186, 0.0771,
0.0334, 0.0109, 0.0028, 6e-04, 1e-04, 0, 0, 0), `2` = c(0.0684,
0.0889, 0.0578, 0.025, 0.0081, 0.0021, 5e-04, 1e-04, 0, 0, 0),
`3` = c(0.0342, 0.0445, 0.0289, 0.0125, 0.0041, 0.0011, 2e-04,
0, 0, 0, 0), `4` = c(0.0128, 0.0167, 0.0108, 0.0047, 0.0015,
4e-04, 1e-04, 0, 0, 0, 0), `5` = c(0.0038, 0.005, 0.0033,
0.0014, 5e-04, 1e-04, 0, 0, 0, 0, 0), `6` = c(0.001, 0.0013,
8e-04, 4e-04, 1e-04, 0, 0, 0, 0, 0, 0), `7` = c(2e-04, 3e-04,
2e-04, 1e-04, 0, 0, 0, 0, 0, 0, 0), `8` = c(0, 1e-04, 0,
0, 0, 0, 0, 0, 0, 0, 0), `9` = c(0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0), `10+` = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)), class = "data.frame", row.names = c("0",
"1", "2", "3", "4", "5", "6", "7", "8", "9", "10+"))
Now if I hardcode the names on the axes (homeScore and awayScore) it works:
df %>%
as_tibble(rownames = "awayScore") %>%
pivot_longer(cols = -awayScore, names_to = "homeScore", values_to = "probability") %>%
mutate_at(vars(awayScore, homeScore), ~forcats::fct_relevel(.x, "10+", after = 10)) %>%
ggplot() +
geom_tile(aes(x=awayScore, y=homeScore, fill = probability)) +
scale_fill_gradient2(low = "red", mid = "white", high = muted("blue"))+
theme(plot.margin = unit(c(2,2,2,2),"cm"))
This is the result:
But now, I want homeScore and awayScore to be variables in a function. So this is my new function with the same df:
TestFunction<-function(home,away){
df %>%
as_tibble(rownames = away) %>%
pivot_longer(cols = -away, names_to = "home", values_to = "probability") %>%
mutate_at(vars(away, home), ~forcats::fct_relevel(.x, "10+", after = 10)) %>%
ggplot() +
geom_tile(aes(x=away, y=home, fill = probability)) +
scale_fill_gradient2(low = "red", mid = "white", high = muted("blue"))+
theme(plot.margin = unit(c(2,2,2,2),"cm"))
}
But this plot is not what's expected:
What do I have to make the homeScore and awayScore on either axes become variables from a function?

Answer 1

When you want to use strings in aes instead of variables names of the dataframe you need to use the function aes_string instead.
Here is your updated code:
TestFunction<-function(home,away){
df %>%
as_tibble(rownames = away) %>%
pivot_longer(cols = -away, names_to = home, values_to = "probability") %>%
mutate_at(vars(away, home), ~forcats::fct_relevel(.x, "10+", after = 10)) %>%
ggplot() +
geom_tile(aes_string(x=away, y=home, fill = "probability")) +
scale_fill_gradient2(low = "red", mid = "white", high = muted("blue"))+
theme(plot.margin = unit(c(2,2,2,2),"cm"))
}
TestFunction("homeScore",'awayScore')
Note that I changed the line pivot_longer to include name_to=home (you had it hardcoded) and also in the aes_string I put quotes in the fill="probability
Output: