Creating "Radar Chart" (A.K.A. Star Plot; Spider Plot) Using Ggplot2 in R

How to create radar chart (spider chart)? can be done by ggplot2?

Provided I understood you correctly, I'd start with something like this:

library(tidyverse)

# Thanks to: https://stackoverflow.com/questions/42562128/ggplot2-connecting-points-in-polar-coordinates-with-a-straight-line-2
coord_radar <- function (theta = "x", start = 0, direction = 1) {
    theta <- match.arg(theta, c("x", "y"))
    r <- if (theta == "x") "y" else "x"
    ggproto("CordRadar", CoordPolar, theta = theta, r = r, start = start, 
            direction = sign(direction),
            is_linear = function(coord) TRUE)
}

df %>%
    pivot_longer(-PCC) %>%
    ggplot(aes(x = name, y = value, colour = PCC, group = PCC)) + 
    geom_line() +
    coord_radar() + 
    theme_minimal()

To generate separate plots per PCC I'd use facets

df %>%
    pivot_longer(-PCC) %>%
    ggplot(aes(x = name, y = value, group = PCC)) + 
    geom_line() +
    coord_radar() + 
    facet_wrap(~ PCC) +
    theme_minimal()

---

Sample data

df <- read.table(text = "  PCC  V1    V2    V3    V4    V5    V6     V7   Vtotal
    1  A  8.67  4.67  6.42  6.92  7.67  6.93   5.72  6.71 
    2  B  6.58  4.67  5.75  3.12  4.67  4.80   5.25  4.98
    3  C  6.50  5.67  7.25  5.75  5.33  6.40  4.00  5.84
    4  D  6.25  5.83  6.00  6.12  4.00  5.00  5.33  5.51
    5  E  9.00  5.67  6.50  8.00  6.17  3.60  5.00  6.28   
    6  F  8.92  7.00  6.62  5.75  7.17  5.90  6.67  6.86
    7  G  5.67  5.83  6.00  5.75  4.92  5.90  4.58  5.52
    8  H  8.92  7.50  9.62  6.50  6.17  7.60  7.33  7.66
    9  I  7.83  4.83  7.12  7.62  6.17  5.40  5.75  6.39
    10 J  7.50  7.67  7.25  8.38  7.17  6.30  7.00  7.32
    11 K  6.83  5.83  5.38  5.12  5.58  6.20  6.17  5.87", header = T)

How to plot a Radar chart in ggplot2 or R

Here is my attempt.First I drew squares using geom_path(). Then, I drew two polygons on top of the squares using geom_polygon(). Finally I added annotations.

### Draw squares
mydf <- data.frame(id = rep(1:6, each = 5),
                   x = c(0, 6, 0, -6, 0,
                         0, 5, 0, -5, 0,
                         0, 4, 0, -4, 0,
                         0, 3, 0, -3, 0,
                         0, 2, 0, -2, 0,
                         0, 1, 0, -1, 0),
                   y = c(6, 0, -6, 0, 6,
                         5, 0, -5, 0, 5,
                         4, 0, -4, 0, 4,
                         3, 0, -3, 0, 3,
                         2, 0, -2, 0, 2,
                         1, 0, -1, 0, 1))

g <- ggplot(data = mydf, aes(x = x, y = y, group = factor(id)) +
     geom_path()

### Draw polygons
mydf2 <- data.frame(id = rep(7:8, each = 5),
                    x = c(0, 6, 0, -5, 0,
                          0, 5, 0, -5, 0),
                    y = c(6, 0, -4, 0, 6,
                          5, 0, -3, 0, 5))

gg <- g +
      geom_polygon(data = mydf2, aes(x = x, y = y, group = factor(id), fill = factor(id))) +
      scale_fill_manual(name = "Time", values = c("darkolivegreen4", "brown4"),
                        labels = c("Past", "Present"))


### Add annotation

mydf3 <- data.frame(x = c(0, 6.5, 0, -6.5),
                    y = c(6.5, 0, -6.5, 0),
                    label = c("system", "supply", "security", "well-being"))


ggg <- gg + 
       annotate("text", x = mydf3$x, y = mydf3$y, label = mydf3$label, size = 3)

ggsave(ggg, file = "name.png", width = 10, height = 9)

How can I plot a radar plot with values from columns?

You can also use the ggradar function from the ggradar package.

library(tidyverse)
library(ggradar)

df = tibble(
  ser = rep(c(4.5, 3.0, 4.0, 1.0, 1.0, 3.5, 4.5, 3.0, 3.0, 4.0, 
             3.0, 4.5, 4.5, 4.0, 3.0, 1.5, 1.5, 2.0, 2.0,
             3.5, 4.5, 3.5, 3.0, 3.0, 4.5, 4.5, 2.5, 4.5),100),
  avg = rep(c(4.5, 3.5, 4.0, 1.0, 4.0, 3.5, 4.5, 4.0, 1.0, 4.0, 
             3.0, 4.5, 4.0, 3.0, 1.5, 1.5, 2.0, 2.0,
             3.5, 4.5, 3.5, 3.5, 4.0, 3.0, 4.0, 4.0, 2.5, 4.5),100))

df %>% pivot_longer(everything()) %>% 
  group_by(name, value) %>% 
  summarise(n = n()/1000) %>% 
  pivot_wider(names_from = value, values_from = n) %>% 
  ggradar(grid.label.size = 4, axis.label.size = 4) 

Generate radar charts with ggplot2

Thanks to @DJack, I post here the result adding + coord_polar():

This is the final code:

ggplot(data=data,  aes(x=X2, y=Count, group=X3, colour=X3)) + 
  geom_point(size=5) + 
  geom_line() + 
  xlab("Decils") + 
  ylab("% difference in nº Pk") + 
  ylim(-50,25) + ggtitle("CL")  + 
  geom_hline(aes(yintercept=0), lwd=1, lty=2) + 
  scale_x_discrete(limits=c(orden_deciles)) +
  coord_polar()

Closing the lines in a ggplot2 radar / spider chart

Sorry, I was beeing stupid. This seems to work:

library(ggplot2) 

# Define a new coordinate system 
coord_radar <- function(...) { 
  structure(coord_polar(...), class = c("radar", "polar", "coord")) 
} 
is.linear.radar <- function(coord) TRUE 

# rescale all variables to lie between 0 and 1 
scaled <- as.data.frame(lapply(mtcars, ggplot2:::rescale01))

scaled$model <- rownames(mtcars)    # add model names as a variable 

as.data.frame(melt(scaled,id.vars="model")) -> mtcarsm


mtcarsm <- rbind(mtcarsm,subset(mtcarsm,variable == names(scaled)[1]))
ggplot(mtcarsm, aes(x = variable, y = value)) + 
    geom_path(aes(group = model)) +
    coord_radar() + facet_wrap(~ model,ncol=4) + 
    theme(strip.text.x = element_text(size = rel(0.8)), 
          axis.text.x = element_text(size = rel(0.8))) 

---

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