Use dataframe variable names in plot titles

Question

I have a dataframe with several variables that I wish to label and then use in several ggplots. I have applied labels using the labeller package with the following code.

library(tidyverse)
library(labeller)
library(ggpubr)

example.df <- data.frame( 
origin = sample(c("hum_1", "mou_1"), 100, replace = TRUE),
v1 = rnorm(100, 100, 5), 
v2 = rnorm(100, 10,5), 
v3 = rnorm (100, 25, 5))

example.df <- example.df %>% set_variable_labels(origin = "original sample", v1 = "effect of Rx", v2 = "response", v3 = "weight (kg)")

This gets the labels to show up in the dataframe. However, when I use ggqqplot from ggpubr to plot these variables I don't see the labels in the resultant plots.

vars <- dput(colnames(select_if(example.df, is.numeric)))

lapply(vars, function(item) {
   ggqqplot(example.df, x=item, combine = FALSE, facet.by = "origin")+
   ggtitle(item)
   }
)

I would like to have original sample, effect of rx and weight (kg) show up instead of v1, v2 and v3. Any help is much appreciated. Thanks.

Don't know about ggqqplot function but it's not too difficult to build your own function to do what you want. See here for examples: stackoverflow.com/a/50522928 & stackoverflow.com/a/50930640 — Tung
– Tung, Commented Mar 12, 2019 at 2:02
Could I create a vector of the labels and use that to pass to ggtitle in the function? I cannot figure out how to write this function. I tried seq_along but it only repeats the first element as the title for all 3 plots. — jaydoc
– jaydoc, Commented Mar 12, 2019 at 4:19

Tung · Accepted Answer · 2019-03-12 19:01:38Z

1

You can give the names to vars then use either map2() or imap() functions from the purrr package to cycle through them. To include superscripts/subscripts/math notation, use expression() together with parse(text = ...) (see also these example1, example2).

names(vars) <- c(expression('effect of Rx'^{1}), 
                 "response", 
                 expression(weight/individual %.% kg[2])
                 )
vars
#>  "effect of Rx"^{\n    1\n}                    response 
#>                        "v1"                        "v2" 
#> weight/individual %.% kg[2] 
#>                        "v3"

### from purrr package
map2(vars, names(vars), ~ ggqqplot(example.df, x = .x, combine = FALSE, facet.by = "origin") +
       ggtitle(parse(text = .y)))

# or `imap(x, ...)` which is short hand for map2(x, names(x), ...) 
imap(vars, ~ ggqqplot(example.df, x = .x, combine = FALSE, facet.by = "origin") +
       ggtitle(parse(text = .y)))


#> $`"effect of Rx"^{\n    1\n}`

#> 
#> $response

#> 
#> $`weight/individual %.% kg[2]`

^{Created on 2019-03-11 by the reprex package (v0.2.1.9000)}

edited Mar 12, 2019 at 19:01

answered Mar 12, 2019 at 4:35

Tung

28.6k8 gold badges98 silver badges129 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

jaydoc Over a year ago

That works. Thanks. One more question. How would I go about using subscripts and superscripts in the labels? For example response<sup> 1 </sup> or response <sub> 2 </sub>? Thanks.

Tung Over a year ago

See these stackoverflow.com/a/34892348 & stackoverflow.com/a/53090311

jaydoc Over a year ago

I tried names(vars) <- c(expression("effect of Rx"^{1}), "response", expression(weight/individual*kg[2])). While there are no errors, the strings do not get evaluated and are printed as is. Where am I going wrong? Adding eval(expression(..)) does not help either.

Tung Over a year ago

See also these stackoverflow.com/a/27741196 & stackoverflow.com/a/51992090

Collectives™ on Stack Overflow

Use dataframe variable names in plot titles

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related