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Time on x-axis

2 messages · Sangeetha Swaminathan, Gabor Grothendieck

Sangeetha Swaminathan
# 
Hello,

   I just started using the GNU R. I am having trouble plotting my data. I am 
tryin to plot the following data:

TIMESTAMP    LOGIN-TIME 
(hh:mm:ss)          (s)

23:55:03       0.990972 
23:55:03       0.990972 
23:50:04       0.878968 
23:45:04       0.969271 
23:40:03       0.868848 
23:35:03        0.88141 
23:30:03       0.679571 
23:25:03       0.599834 
23:20:03       0.663436 
23:15:03       0.567414 
23:10:02       0.738379 
23:05:02       0.575764

with TIMESTAMP on the x-axis. The plot() function assumes the x-axis as the 
total number of events, and plots the desired graph. But I want the TIMESTAMP 
on the x-axis. If I try to change the x-axis, the y-axis gets modified too, 
and all I get is just a "dot" as a plot. 
Can someone tell me how I can make R plot my graph, with TIMESTAMP as my 
x-axis and LOGIN_TIME as my y-axis?

Thank you.

Sangeetha

-- Sangeetha Swaminathan
Graduate Assistant
Innovative Technology Center (ITC)
2444 Dunford Hall
The University of Tennessee
Knoxville, TN 37996
Phone [O]:(865) 974-9672
      [R]:(865) 946-4340
Gabor Grothendieck
# 
Try this:

# test data
tt <- c("23:05:02", "23:10:02", "23:15:03", "23:20:03", "23:25:03",
"23:30:03", "23:35:03", "23:40:03", "23:45:04", "23:50:04", "23:55:03",
"23:55:03")
x <- c(0.575764, 0.738379, 0.567414, 0.663436, 0.599834, 0.679571,
0.88141, 0.868848, 0.969271, 0.878968, 0.990972, 0.990972)

library(zoo)
library(chron)
z <- zoo(x, times(tt))
plot(z)

Read the R Help Desk article in R News 4/1 about dates and times
and also read the chron article in its references.

Also read the zoo vignette which you can access like this:

library(zoo)
vignette("zoo")

and also read ?axis in case you want to customize the axes.
On 2/20/06, Sangeetha Swaminathan <sangi at itc.utk.edu> wrote: