R語言繪制坐標保存圖片的操作

更新時間：2021年04月06日 09:18:42 作者：遠涉江湖

這篇文章主要介紹了R語言繪制坐標保存圖片的操作，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧

繪制坐標

有時候我們繪制坐標的時候，需要改變坐標軸的定義，我們以日期為橫坐標繪制時間序列為例講解

先列舉簡單的例子：

rnorm(n, mean = 0, sd = 1)

n 為產(chǎn)生隨機值個數(shù)（長度），mean 是平均數(shù)， sd 是標準差。

> rnorm(10,1,sd = 2)
 [1] 1.98984356 -1.93403191 -1.15324772 0.84623524 -0.73123833 -2.77682328 -0.74316683 -0.02913632 -0.80063421 3.23976243

用隨機數(shù)繪制曲線：

require(stats) # for rnorm
plot(x=1:10, y=rnorm(10,1,sd = 2), type = 'l')

type 參數(shù)：

what type of plot should be drawn. Possible types are
"p" for points,
"l" for lines,
"b" for both,
"c" for the lines part alone of "b",
"o" for both ‘overplotted',
"h" for ‘histogram' like (or ‘high-density') vertical lines,
"s" for stair steps,
"S" for other steps, see ‘Details' below,

把上述內(nèi)容繪制成時間序列

> plot(x=1:10, y=rnorm(10,1,sd = 2), type = 'l',<span style="color:#cc0000;"><strong>xaxt='n'</strong></span>) # 原坐標X 不繪制，否則會重疊
> axis(side = 1, at = c(2,4,6,8,10), labels = c("2016-05-24", "2016-05-26", "2016-05-30", "2016-06-01", "2016-06-03"))

自動保存成圖片文件

png(filename = "Rplot%03d.png",
 width = 480, height = 480, units = "px", pointsize = 12,
 bg = "white", res = NA, family = "", restoreConsole = TRUE,
 type = c("windows", "cairo", "cairo-png"), antialias)

在 plot 的上方和下方加入 png function 和 devoff():

require(stats) # for rnorm
<span style="color:#cc0000;">png(file='draw.png', bg="white", width = 300, height = 200)</span>
plot(x=1:10, y=rnorm(10,1,sd = 2), type = 'l',xaxt='n', <strong><span style="color:#ff0000;">main = 'draw'</span></strong>) # 增加坐標的 名稱 draw
axis(side = 1, at = c(2,4,6,8,10), labels = c("2016-05-24", "2016-05-26", "2016-05-30", "2016-06-01", "2016-06-03"))
<span style="color:#cc0000;">dev.off()</span>