How to correlate and visualise correlation of one variable versus many

Question

I want to use R to visualise and calculate the correlation of one variable data[1] to many other variables data[2:96]

I am already aware of what packages such as psych and PerformanceAnalytics have the Pairs function.

Ideally, I would like to output a graph like that Pairs outputs, but only for the correlations between data[1] and each of data[2:96], not for each of the elements of data[1:96] with itself, that would take up too much space. Any ideas on this would be appreciated.

Answer 1

Can use the corrr package to focus() on your variable of choice, then ggplot2 package to plot the results. For example, get/plot correlations of mpg with all other variables in the mtcars data set:

library(corrr)
library(ggplot2)

x <- mtcars %>% 
  correlate() %>% 
  focus(mpg)
x
#> # A tibble: 10 x 2
#>    rowname        mpg
#>      <chr>      <dbl>
#> 1      cyl -0.8521620
#> 2     disp -0.8475514
#> 3       hp -0.7761684
#> 4     drat  0.6811719
#> 5       wt -0.8676594
#> 6     qsec  0.4186840
#> 7       vs  0.6640389
#> 8       am  0.5998324
#> 9     gear  0.4802848
#> 10    carb -0.5509251

x %>% 
  mutate(rowname = factor(rowname, levels = rowname[order(mpg)])) %>%  # Order by correlation strength
  ggplot(aes(x = rowname, y = mpg)) +
    geom_bar(stat = "identity") +
    ylab("Correlation with mpg") +
    xlab("Variable")

Answer 2

Using mtcars data and the corrplot{} package:

install.packages("corrplot")
library(corrplot)
mcor <- cor(x = mtcars$mpg, y = mtcars[2:11], use="complete.obs")
corrplot(mcor, tl.srt = 25)

Edit: Forgot to put in a vignette for corrplot showing more ways to format it: https://cran.r-project.org/web/packages/corrplot/vignettes/corrplot-intro.html

Answer 3

You can also retrieve subsets of the correlation matrix to solve this. For example, cor(data)[,1] gives the correlations between column 1 and all the others.