R图:大小和分辨率 [英] R plot: size and resolution

问题描述

我已经提出了一个问题:我需要绘制DPI = 1200和特定打印尺寸的图像.

I have stacked into the question: I need to plot the image with DPI=1200 and specific print size.

默认情况下，png看起来不错...

By default the png looks ok...

png("test.png",width=3.25,height=3.25,units="in",res=1200)
par(mar=c(5,5,2,2),xaxs = "i",yaxs = "i",cex.axis=1.3,cex.lab=1.4)
plot(perf,avg="vertical",spread.estimate="stddev",col="black",lty=3, lwd=3)
dev.off()

但是，当我应用此代码时，图像变得非常糟糕，无法缩放(适合)所需的大小.我错过了什么?如何将图像拟合"到情节?

But when I apply this code, the image became really terrible it's not scaling (fit) to the size that is needed. What did I miss? How to "fit" the image to the plot?

，

推荐答案

可重现的示例:

the_plot <- function()
{
  x <- seq(0, 1, length.out = 100)
  y <- pbeta(x, 1, 10)
  plot(
    x,
    y,
    xlab = "False Positive Rate",
    ylab = "Average true positive rate",
    type = "l"
  )
}

詹姆斯建议使用pointsize并结合各种cex参数，可以产生合理的结果.

James's suggestion of using pointsize, in combination with the various cex parameters, can produce reasonable results.

png(
  "test.png",
  width     = 3.25,
  height    = 3.25,
  units     = "in",
  res       = 1200,
  pointsize = 4
)
par(
  mar      = c(5, 5, 2, 2),
  xaxs     = "i",
  yaxs     = "i",
  cex.axis = 2,
  cex.lab  = 2
)
the_plot()
dev.off()

---

当然，更好的解决方案是放弃这种对基本图形的摆弄，而使用可以为您处理分辨率缩放的系统.例如，

---

Of course the better solution is to abandon this fiddling with base graphics and use a system that will handle the resolution scaling for you. For example,

library(ggplot2)

ggplot_alternative <- function()
{
  the_data <- data.frame(
    x <- seq(0, 1, length.out = 100),
    y = pbeta(x, 1, 10)
  )

ggplot(the_data, aes(x, y)) +
    geom_line() +
    xlab("False Positive Rate") +
    ylab("Average true positive rate") +
    coord_cartesian(0:1, 0:1)
}

ggsave(
  "ggtest.png",
  ggplot_alternative(),
  width = 3.25,
  height = 3.25,
  dpi = 1200
)

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