[R] Is there a simple way to analyse all the data using dplyr?

Chris Evans chr|@ho|d @end|ng |rom p@yctc@org
Mon Sep 21 14:12:53 CEST 2020

I am sure the answer is "yes" and I'm also sure the question may sound mad. Here's a reprex that I think captures what I'm doing 

n <- 500 
gender <- sample(c("Man","Woman","Other"), n, replace = TRUE) 
GPC_score <- rnorm(n) 
scaleMeasures <- runif(n) 
bind_cols(gender = gender, 
GPC_score = GPC_score, 
scaleMeasures = scaleMeasures) -> tibUse 

### let's have the correlation between the two variables broken down by gender 
tibUse %>% 
  filter(gender != "Other") %>% 
  select(gender, GPC_score, scaleMeasures) %>% 
  na.omit() %>% 
  group_by(gender) %>% 
  summarise(cor = cor(cur_data())[1,2]) -> tmp1 

### but I'd also like the correlation for the whole dataset, not by gender 
### this is a kludge to achieve that which I am using partly because I cant' 
### find the equivalent of cur_data() for an ungrouped tibble/df 
tibUse %>% 
  mutate(gender = "All") %>% # nasty kludge to get all the data! 
  select(gender, GPC_score, scaleMeasures) %>% 
  na.omit() %>% 
  group_by(gender) %>% # ditto! 
  summarise(cor = cor(cur_data())[1,2]) -> tmp2 


### gets me what I want:
# A tibble: 3 x 2 
gender cor 
<chr> <dbl> 
1 Man 0.0225 
2 Woman 0.0685 
3 All 0.0444

In reality I have some functions that are more complex than cor()[2,1] (sorry about that particular kludge) that digest dataframes and I'd love to have a simpler way of doing this.

So two questions: 
1) I am sure there a term/function that works on an ungrouped tibble in dplyr as cur_data() does for a grouped tibble ... but I can't find it.
2) I suspect someone has automated a way to get the analysis of the complete data after the analyses of the groups within a single dplyr run ... it seems an obvious and common use case, but I can't find that either.

Sorry, I'm over 99% sure I'm being stupid and missing the obvious here ... but that's the recurrent problem I have with my wetware and searchware doesn't seem to being fixing this!



Small contribution in our coronavirus rigours: 

Chris Evans <chris using psyctc.org> Visiting Professor, University of Sheffield <chris.evans using sheffield.ac.uk>
I do some consultation work for the University of Roehampton <chris.evans using roehampton.ac.uk> and other places
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