R语言绘制坐标保存图片的操作

2024-04-02 19:55

短信预约 -IT技能 免费直播动态提醒

绘制坐标

有时候我们绘制坐标的时候，需要改变坐标轴的定义，我们以日期为横坐标绘制时间序列为例讲解

先列举简单的例子：


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

n 为产生随机值个数（长度），mean 是平均数， sd 是标准差。


> 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

用随机数绘制曲线：


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

type 参数：


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,

把上述内容绘制成时间序列


> plot(x=1:10, y=rnorm(10,1,sd = 2), type = 'l',<span style="color:#cc0000;"><strong>xaxt='n'</strong></span>) # 原坐标X 不绘制，否则会重叠
> 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"))

自动保存成图片文件


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>) # 增加坐标的 名称 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>