How to loop over multiple groups and create radar plots in R

Question

I have the following dataframe:

group	Class	Maths	Science
Name1	7	74	78
Name2	7	80	91
Name3	6	69	80

I want to create different radar plots for the variables Maths and Science for each classes using R. eg: For the above dataframe, two radar plots should be created for two classes 7 and 6.

nrange <- 2
class <- c(7,6)
for (i in nrange){
plot <- ggradar::ggradar(df[i,2:3], values.radar = c(0, 50, 100), group.line.width = 1,
               group.point.size = 2, legend.position = "bottom", plot.title=class[i])
}
plot

I using the above code. However, it is only creating the plot for the last row. Please help me with this issue.

Thanks a lot in advance!

DaveArmstrong · Accepted Answer · 2023-02-06T18:31:29.997

0

You were almost there, but there were two little problems.

The for statement evaluated to for(i in 2) which means it is only using i=2. You can fix this by using for(i in 1:nrange)
You were overwriting plot each time through the loop. If you make plot a list and save each graph as a separate element in the list, then it should work.

mydat <- tibble::tribble(
  ~group,   ~Class, ~Maths, ~Science,
"Name1",    7,  74, 78,
"Name2",    7,  80, 91,
"Name3",    6,  69, 80)

plots <- list()
nrange <- 2
class <- c(7,6)
for (i in 1:3){
  plots[[i]] <- ggradar::ggradar(mydat[i,2:4], values.radar = c(0, 50, 100), 
                           grid.max = 100, group.line.width = 1,
                           group.point.size = 2, legend.position = "bottom", plot.title=mydat$Class[i])
}
plots
#> [[1]]

#> 
#> [[2]]

#> 
#> [[3]]

^{Created on 2023-02-03 by the reprex package (v2.0.1)}

Putting Together with facet_wrap()

library(dplyr)
library(ggplot2)
mydat <- tibble::tribble(
  ~group,   ~Class, ~Maths, ~Science,
  "Name1",    7,  74, 78,
  "Name2",    7,  80, 91,
  "Name3",    6,  69, 80)

mydat <- mydat %>% 
  mutate(gp = paste(group, Class, sep=": ")) %>% 
  select(gp, Maths, Science)

  ggradar::ggradar(mydat, values.radar = c(0, 50, 100), 
                                 grid.max = 100, group.line.width = 1,
                                 group.point.size = 2, legend.position = "bottom") + 
    facet_wrap(~gp)

^{Created on 2023-02-06 by the reprex package (v2.0.1)}

edited Feb 06 '23 at 18:31

answered Feb 03 '23 at 11:45

DaveArmstrong

18,377
2
13
25

Hey!, I also tried this code but it gives me this error: `Error: 'plot.data' contains value(s) > grid.max` – Talha Asif Feb 03 '23 at 11:47
1

You can set `grid.max=100` in the code and that will solve the problem. – DaveArmstrong Feb 03 '23 at 11:58
Thanks a lot. It worked perfectly! However, the plots are not showing the legend at the bottom. How can I get the legends for each group in individual plots? – kamalika ray Feb 03 '23 at 12:12
The legend isn't showing up because in each plot, you've only got one group. If you did `ggradar(mydat, grid.max=100)` you would see that you get a legend, – DaveArmstrong Feb 03 '23 at 12:17
Hi @DaveArmstrong. Can I do the same with the function facet_wrap and get all the plots in one? – kamalika ray Feb 06 '23 at 14:35
@kamalikaray Yes, I updated the answer to show how. – DaveArmstrong Feb 06 '23 at 18:31

How to loop over multiple groups and create radar plots in R

1 Answers1

Putting Together with facet_wrap()