雷达图的R - y轴极限

Question

我用了下面的例子来回答我的问题:http://www.cmap.polytechnique.fr/lepennec/R/雷达/RadarAndParallelPlots.html

mtcarsscaled <- as.data.frame(lapply(mtcars, ggplot2:::rescale01))
mtcarsscaled$model <- rownames(mtcars)
mtcarsmelted <- reshape2::melt(mtcarsscaled)
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)
}
plot <- ggplot(mtcarsmelted, aes(x = variable, y = value)) +
  geom_polygon(aes(group = model, color = model), fill = NA, size = 2, show.legend = FALSE) +
  geom_line(aes(group = model, color = model), size = 2) +
  theme(strip.text.x = element_text(size = rel(0.8)),
        axis.text.x = element_text(size = rel(0.8)),
        axis.ticks.y = element_blank(),
        axis.text.y = element_blank()) +
  xlab("") + ylab("") +
  guides(color = guide_legend(ncol=2)) +
  coord_radar()
print(plot)

如何定义y轴的极限?目前，最低值将在雷达图的中间，不会显示零。我希望0位于图的中间，而不是图的中间/中心作为最低值。

任何帮助都非常感谢!

Answer 1

我发现它只适用于

  scale_y_continuous(limits=c(0,10), breaks=c(1,2,3,4,5,6,7,8,9,10))

…但我必须把值换成a。事先数字。