Question

I created a radar chart using the function of “radarchart” from the “fmsb” package in R software.

The matrix I am using is as follows:

x<-c(c(rep(4.5,7),c(rep(0,7)), 3.34, 3.28, 1.37, 1.12, 3.52, 4.07, 3.66));
a<-as.data.frame(matrix(x,nrow=3, ncol=7,byrow=T))
radarchart(a,axistype=4,seg=3,cglty=3,pty=32,cglcol=1,plwd=3,pcol=1,axislabcol=1)

I would like to show the range of c(0,5) on the axis instead of c(0,100) or c(0,1).
I really appreciate it if any body can guide me.

Answer 1

By using a rather quick tweak, radarchart now has an additional argument which allows you to manually specify the numbers on the axes:

require(fmsb)
x = c(rep(4.5,7),rep(0,7), 
      3.34, 3.28, 1.37, 1.12, 3.52, 4.07, 3.66)
a = as.data.frame(matrix(x,nrow=3, ncol=7,byrow=T))
radarchart(a, axistype = 4, seg = 3, cglty = 3, 
           pty = 32, cglcol = 1, plwd = 3, pcol = 1, axislabcol = 1,
           labels = seq(from = min(x), to = max(x), length = 4))

The updated source code, my additions are marked by comments:

radarchart = function (df, axistype = 0, seg = 4, pty = 16, pcol = 1:8, plty = 1:6, 
          plwd = 1, cglty = 3, cglwd = 1, cglcol = "navy", axislabcol = "blue", 
          title = "", maxmin = TRUE, na.itp = TRUE, labels = NULL, ...) 
{
  if (!is.data.frame(df)) {
    cat("The data must be given as dataframe.\n")
    return()
  }
  if ((n <- length(df)) < 3) 
    return()
  if (maxmin == FALSE) {
    dfmax <- apply(df, 2, max)
    dfmin <- apply(df, 2, min)
    df <- rbind(dfmax, dfmin, df)
  }
  plot(c(-1.2, 1.2), c(-1.2, 1.2), type = "n", frame.plot = FALSE, 
       axes = FALSE, xlab = "", ylab = "", main = title, asp = 1, 
       ...)
  theta <- seq(90, 450, length = n + 1) * pi/180
  theta <- theta[1:n]
  xx <- cos(theta)
  yy <- sin(theta)
  for (i in 0:seg) {
    polygon(xx * (i + 1)/(seg + 1), yy * (i + 1)/(seg + 1), 
            lty = cglty, lwd = cglwd, border = cglcol)
    if (axistype == 1 | axistype == 3) 
     ## Changes by me  
     if(is.null(labels)) labels = paste(i/seg * 100, 
                                         "(%)")
      text(-0.05, (i + 1)/(seg + 1), labels[i+1], col = axislabcol)
    if (axistype == 4 | axistype == 5) 
      ## Changes by me
      if(is.null(labels)) labels = sprintf("%3.2f", i/seg)
      text(-0.05, (i + 1)/(seg + 1), labels[i+1], 
           col = axislabcol)
  }
  arrows(xx/(seg + 1), yy/(seg + 1), xx * 1, yy * 1, lwd = cglwd, 
         lty = cglty, length = 0, col = cglcol)
  if (axistype == 2 | axistype == 3 | axistype == 5) {
    text(xx[1:n], yy[1:n], df[1, 1:n], col = axislabcol)
  }
  text(xx * 1.2, yy * 1.2, colnames(df))
  series <- length(df[[1]])
  if (length(pty) < (series - 2)) {
    ptys <- rep(pty, series - 2)
    pcols <- rep(pcol, series - 2)
    pltys <- rep(plty, series - 2)
    plwds <- rep(plwd, series - 2)
  }
  else {
    ptys <- pty
    pcols <- pcol
    pltys <- plty
    plwds <- plwd
  }
  for (i in 3:series) {
    xxs <- xx
    yys <- yy
    scale <- 1/(seg + 1) + (df[i, ] - df[2, ])/(df[1, ] - 
      df[2, ]) * seg/(seg + 1)
    if (sum(!is.na(df[i, ])) < 3) {
      cat(sprintf("[DATA NOT ENOUGH] at %d\n%g\n", i, df[i, 
                                                         ]))
    }
    else {
      for (j in 1:n) {
        if (is.na(df[i, j])) {
          if (na.itp) {
            left <- ifelse(j > 1, j - 1, n)
            while (is.na(df[i, left])) {
              left <- ifelse(left > 1, left - 1, n)
            }
            right <- ifelse(j < n, j + 1, 1)
            while (is.na(df[i, right])) {
              right <- ifelse(right < n, right + 1, 1)
            }
            xxleft <- xx[left] * (1/(seg + 1) + (df[i, 
                                                    left] - df[2, left])/(df[1, left] - df[2, 
                                                                                           left]) * seg/(seg + 1))
            yyleft <- yy[left] * (1/(seg + 1) + (df[i, 
                                                    left] - df[2, left])/(df[1, left] - df[2, 
                                                                                           left]) * seg/(seg + 1))
            xxright <- xx[right] * (1/(seg + 1) + (df[i, 
                                                      right] - df[2, right])/(df[1, right] - 
                                                        df[2, right]) * seg/(seg + 1))
            yyright <- yy[right] * (1/(seg + 1) + (df[i, 
                                                      right] - df[2, right])/(df[1, right] - 
                                                        df[2, right]) * seg/(seg + 1))
            if (xxleft > xxright) {
              xxtmp <- xxleft
              yytmp <- yyleft
              xxleft <- xxright
              yyleft <- yyright
              xxright <- xxtmp
              yyright <- yytmp
            }
            xxs[j] <- xx[j] * (yyleft * xxright - yyright * 
              xxleft)/(yy[j] * (xxright - xxleft) - xx[j] * 
              (yyright - yyleft))
            yys[j] <- (yy[j]/xx[j]) * xxs[j]
          }
          else {
            xxs[j] <- 0
            yys[j] <- 0
          }
        }
        else {
          xxs[j] <- xx[j] * (1/(seg + 1) + (df[i, j] - 
            df[2, j])/(df[1, j] - df[2, j]) * seg/(seg + 
            1))
          yys[j] <- yy[j] * (1/(seg + 1) + (df[i, j] - 
            df[2, j])/(df[1, j] - df[2, j]) * seg/(seg + 
            1))
        }
      }
      polygon(xxs, yys, lty = pltys[i - 2], lwd = plwds[i - 
        2], border = pcols[i - 2])
      points(xx * scale, yy * scale, pch = ptys[i - 2], 
             col = pcols[i - 2])
    }
  }
}