[R] Plot Rect Transparency
re|chm@nj @end|ng |rom @bcg|ob@|@net
Fri Jun 29 04:03:31 CEST 2018
Thanks I was able to find it in the help doc.
x <- c(1,2,4,6,8,9,10,12,13,14,18,20)
y <- c(4,5,3,6,7,4,8,9,12,4,7,5)
mydata <- data.frame(x,y)
rect(5,0,8,8, col=rgb(0,1,0,alpha=0.2), border=F)
From: Duncan Murdoch <murdoch.duncan using gmail.com>
Sent: Thursday, June 28, 2018 7:57 PM
To: reichmanj using sbcglobal.net; R-help using r-project.org
Subject: Re: [R] Plot Rect Transparency
On 28/06/2018 5:29 PM, Jeff Reichman wrote:
> Is there a way to make a rectangle transparent (alpha=0.1??)
> plot(c(100, 200), c(300, 450), type= "n", xlab = "", ylab = "")
> rect(110, 300, 175, 350, density = 5, border = "red")
> Can't figure out how to take the changepoint function results and plot
> ggplot2 so I can just simply add rectangles to the plot function, but
> I need to make transparent and there doesn't seem to be an alpha option.
Alpha is part of the colour spec. For example,
rect(110, 300, 175, 350, density = 5, border = rgb("red")
rect(110, 300, 175, 350, density = 5, border = rgb(red=1, green=0, blue=0, alpha=0.1))
I'm not sure what is the quickest way to work out the rgb values for a named colour (col2rgb can do it, but not in a convenient format) if you want to add alpha to it.
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