R help - Apr 2010 - ggplot2 geom_rect(): What am I missing here

Hi R fans,

As a newbie following the five-hour rule (after hitting my head against 
the wall for five hours, post to this list), I am appealing for some 
help understanding geom_rect() in ggplot2.

What I want to do is very simple. I want to generate a plot of 
rectangles. Each one represents a business cycle. The x-values will be 
pairs representing the start and end of each cycle. The y-values 
represent the duration of the cycle (in months). In other words, all 
rectangles have coordinates (start, duration) and (end, duration).
rr
I've spent hours trying to figure out the documentation and pouring over 
Google and RSeek searches and am at an impasse. The documentation refers 
to xmin, xmax, ymin, and ymax but doesn't say anything about them. The 
only example gives them both as vectors, so I assume they refer to a 
sequence of coordinates in which each rectangle's vertices is given by 
(xmin[i],ymin[i]), (xmin[i],ymax[i]), (xmax[i],ymax[i]), and 
(xmax[i],ymin[i]). But when I try to plot something simple using this 
understanding,  I get a blank plot.

Here's my code:

    df <- data.frame(
             xmin = c(1,5),
             xmax = c(2,7),
             ymin = c(0,3),
             ymax = c(2,5)
             )
    ggplot(df, aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymin)) +
             geom_rect(fill="grey80")

Please help me before I Google again! :-)

Thanks.

    Marsh Feldman


	[[alternative HTML version deleted]]

On Apr 4, 2010, at 4:18 PM, Marshall Feldman wrote:
> Hi R fans,
>
> As a newbie following the five-hour rule (after hitting my head  
> against
> the wall for five hours, post to this list), I am appealing for some
> help understanding geom_rect() in ggplot2.
>
> What I want to do is very simple. I want to generate a plot of
> rectangles. Each one represents a business cycle. The x-values will be
> pairs representing the start and end of each cycle. The y-values
> represent the duration of the cycle (in months). In other words, all
> rectangles have coordinates (start, duration) and (end, duration).
> rr
> I've spent hours trying to figure out the documentation and pouring  
> over
> Google and RSeek searches and am at an impasse. The documentation  
> refers
> to xmin, xmax, ymin, and ymax but doesn't say anything about them. The
> only example gives them both as vectors, so I assume they refer to a
> sequence of coordinates in which each rectangle's vertices is given by
> (xmin[i],ymin[i]), (xmin[i],ymax[i]), (xmax[i],ymax[i]), and
> (xmax[i],ymin[i]). But when I try to plot something simple using this
> understanding,  I get a blank plot.
>
> Here's my code:
>
>    df <- data.frame(
>             xmin = c(1,5),
>             xmax = c(2,7),
>             ymin = c(0,3),
>             ymax = c(2,5)
>             )
I have an allergy to naming data objects with names that apply to R  
functions so I used df1 as the object name. I have not taken the time  
to learn ggplot but here is a base graphics attempt:

plot(NULL , xlim=c(min(df1$xmin), max(df1$xmax)),
             ylim=c(min(df1$ymin), max(df1$ymax)) ) # sets up blank plot
  with(df1, rect(xmin, ymin, xmax, ymax) )

-- 
David.


 >
>    ggplot(df, aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax =  
> ymin)) +
>             geom_rect(fill="grey80")
>
> Please help me before I Google again! :-)
>
> Thanks.
>
>    Marsh Feldman
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT

Marsh,

Your rectangles won't be very tall with ymax=ymin!
(I hope that wasn't the cause of the 5 hours.)

  -Peter Ehlers

On 2010-04-04 14:18, Marshall Feldman wrote:
> Hi R fans,
>
> As a newbie following the five-hour rule (after hitting my head against
> the wall for five hours, post to this list), I am appealing for some
> help understanding geom_rect() in ggplot2.
>
> What I want to do is very simple. I want to generate a plot of
> rectangles. Each one represents a business cycle. The x-values will be
> pairs representing the start and end of each cycle. The y-values
> represent the duration of the cycle (in months). In other words, all
> rectangles have coordinates (start, duration) and (end, duration).
> rr
> I've spent hours trying to figure out the documentation and pouring
over
> Google and RSeek searches and am at an impasse. The documentation refers
> to xmin, xmax, ymin, and ymax but doesn't say anything about them. The
> only example gives them both as vectors, so I assume they refer to a
> sequence of coordinates in which each rectangle's vertices is given by
> (xmin[i],ymin[i]), (xmin[i],ymax[i]), (xmax[i],ymax[i]), and
> (xmax[i],ymin[i]). But when I try to plot something simple using this
> understanding,  I get a blank plot.
>
> Here's my code:
>
>      df<- data.frame(
>               xmin = c(1,5),
>               xmax = c(2,7),
>               ymin = c(0,3),
>               ymax = c(2,5)
>               )
>      ggplot(df, aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymin)) +
>               geom_rect(fill="grey80")
>
> Please help me before I Google again! :-)
>
> Thanks.
>
>      Marsh Feldman
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
-- 
Peter Ehlers
University of Calgary

On Apr 4, 2010, at 4:18 PM, Marshall Feldman wrote:
> Hi R fans,
>
> As a newbie following the five-hour rule (after hitting my head  
> against
> the wall for five hours, post to this list), I am appealing for some
> help understanding geom_rect() in ggplot2.
>
> What I want to do is very simple. I want to generate a plot of
> rectangles. Each one represents a business cycle. The x-values will be
> pairs representing the start and end of each cycle. The y-values
> represent the duration of the cycle (in months). In other words, all
> rectangles have coordinates (start, duration) and (end, duration).
> rr
> I've spent hours trying to figure out the documentation and pouring  
> over
> Google and RSeek searches and am at an impasse. The documentation  
> refers
> to xmin, xmax, ymin, and ymax but doesn't say anything about them. The
> only example gives them both as vectors, so I assume they refer to a
> sequence of coordinates in which each rectangle's vertices is given by
> (xmin[i],ymin[i]), (xmin[i],ymax[i]), (xmax[i],ymax[i]), and
> (xmax[i],ymin[i]). But when I try to plot something simple using this
> understanding,  I get a blank plot.
>
> Here's my code:
>
>    df <- data.frame(
>             xmin = c(1,5),
>             xmax = c(2,7),
>             ymin = c(0,3),
>             ymax = c(2,5)
>             )
>    ggplot(df, aes(xmin = xmin, xmax = xmax, ymin = ymin, )) +
>             geom_rect(fill="grey80")
I took a crack at starting with the code at Hadley's help page for  
geom_rect and got what appearred to work (with a dataframe names
"df1"):

  ggplot(df1, aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax)) +
         geom_rect(fill="grey")

Quite honestly I had a very hard time  figuring out how that was  
different than what you did (or what I did earlier that seemed to fill  
in the entire plot area) but then I noticed that you had put in "ymax  
= ymin" when you clearly meant something else.
>
> Please help me before I Google again! :-)
>
> Thanks.
>
>    Marsh Feldman
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT

Thanks to David Winsemius, Peter Ehlers, and Paul Murrell who pointed 
out my careless error working with ggplot2's geom_rect(). Not to make 
excuses, but when you've done something successfully dozens of times and 
suddenly it doesn't work, you're more likely to look for careless errors
on your part. When you've never done something before and unsure that 
you understand the proper use of the tool, you're more likely to think 
you're missing something about the tool's proper use and to overlook 
your own careless errors.

This list is great! I posted my question, went off to do something else, 
and within a few hours had the answer to my problem.

Thanks again

     Marsh Feldman