R help - Jan 2010 - Line Plot with Dates on X-axis

I am trying to generate a line graph with quarterly time buckets (with
nice labels) on the x-axis.  The first block of code below will
generate the graph with nicely formatted x-axis labels, but the
"type=" and "col=" options are not recognized when factors
are used
for the x-axis.

The second block, where the quarter values are mapped into dates, will
plot the line nicely but the x-axis is the number of days since
1/1/1970.  How do I either get the first block to recognize the
desired format, or the second block to format the x-axis as quarters?

Thank you in advance!

#block 1
time.val <- as.factor(c
("2004Q1","2004Q2","2004Q3","2004Q4","2005Q1","2005Q2"))
inc <- c(0.9903797, 1.3741467, 0.9938702, 0.4252443, 0.7700158,
1.1770313)

# returns nice x-axis, but black points
plot(time.val, inc, type="b", col="red")

#block 2
time2 <-
  ifelse (substr(time.val,5,6) == "Q1",
   
as.Date(paste("1/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"),
  ifelse (substr(time.val,5,6) == "Q2",
   
as.Date(paste("4/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"),
  ifelse (substr(time.val,5,6) == "Q3",
   
as.Date(paste("7/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"),
   
as.Date(paste("10/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"))))

#returns red lines but the axis is the number of days since 1/1/1970
plot(time2, inc, type="b", col="red")

Try the zoo package:

plot(as.yearqtr(time.val), inc, col = 'red', type = 'l')

On Wed, Jan 20, 2010 at 3:41 PM, mah <harwood262 at gmail.com>
wrote:
> I am trying to generate a line graph with quarterly time buckets (with
> nice labels) on the x-axis. ?The first block of code below will
> generate the graph with nicely formatted x-axis labels, but the
> "type=" and "col=" options are not recognized when
factors are used
> for the x-axis.
>
> The second block, where the quarter values are mapped into dates, will
> plot the line nicely but the x-axis is the number of days since
> 1/1/1970. ?How do I either get the first block to recognize the
> desired format, or the second block to format the x-axis as quarters?
>
> Thank you in advance!
>
> #block 1
> time.val <- as.factor(c
>
("2004Q1","2004Q2","2004Q3","2004Q4","2005Q1","2005Q2"))
> inc <- c(0.9903797, 1.3741467, 0.9938702, 0.4252443, 0.7700158,
> 1.1770313)
>
> # returns nice x-axis, but black points
> plot(time.val, inc, type="b", col="red")
>
> #block 2
> time2 <-
> ?ifelse (substr(time.val,5,6) == "Q1",
> ?
?as.Date(paste("1/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"),
> ?ifelse (substr(time.val,5,6) == "Q2",
> ?
?as.Date(paste("4/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"),
> ?ifelse (substr(time.val,5,6) == "Q3",
> ?
?as.Date(paste("7/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"),
> ?
?as.Date(paste("10/1/",substr(time.val,1,4),sep=""),"%m/%d/%Y"))))
>
> #returns red lines but the axis is the number of days since 1/1/1970
> plot(time2, inc, type="b", col="red")
>
> ______________________________________________
> 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.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O