R help - Jun 2008 - newbie needs help plotting time series

Dear R help list

I have recently started using R to visualize time series of water level
measurements. The code I wrote
does exactly what I want:

plot(x, a$B112, axes=FALSE, ylim=c(405,410), col="red", pch=15, 
type="o", ylab="metres above sea level", main="Main
Plot Title")
axis(2, at=405:410, tck=1, col="gray60")
axis.Date(1, at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month"), labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month"), tck=1, col="gray60")

Now I wanted to shift the data visualized by 6 months, so I replaced
"2004-01-01" by "2004-07-01"
and "2008-06-01" by "2008-12-01". Instead of the desired
plot, I get an error message stating
(forgive the perhaps faulty translation into English, I'm working on a
German version of R):

mistake in axis(side, at = z, labels = labels, ...) : 
  length of 'at' and 'labels' different, 50 != 54

What have I done wrong? Thank you very much for your help!

Katharina Dubach

Hi

r-help-bounces at r-project.org napsal dne 30.06.2008 11:14:48:
> Dear R help list
> 
> I have recently started using R to visualize time series of water level 
> measurements. The code I wrote 
> does exactly what I want:
> 
> plot(x, a$B112, axes=FALSE, ylim=c(405,410), col="red", pch=15, 
> type="o", ylab="metres above sea level",
main="Main Plot Title")
> axis(2, at=405:410, tck=1, col="gray60")
> axis.Date(1, at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
> by="month"), labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
> by="month"), tck=1, col="gray60")
> 
> Now I wanted to shift the data visualized by 6 months, so I replaced 
> "2004-01-01" by "2004-07-01" 
> and "2008-06-01" by "2008-12-01". Instead of the
desired plot, I get an
error 
> message stating 
> (forgive the perhaps faulty translation into English, I'm working on a 
German 
> version of R):
> 
> mistake in axis(side, at = z, labels = labels, ...) : 
>   length of 'at' and 'labels' different, 50 != 54
Those two calls have different length

at=seq(as.Date("2004-01-01"), as.Date("2008-06-01"),
by="month")
labels=seq(as.Date("2004-01-01"), as.Date("2008-06-01"),
by="month")

you can try it by

length(seq(...))

could not there be some typo in your call?

Regards

Petr

> 
> What have I done wrong? Thank you very much for your help!
> 
> Katharina Dubach
> 
> ______________________________________________
> 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.

"Kathi" <kathi at dropnet.ch> napsal dne 01.07.2008 13:39:18:
> Thanks, Petr. 
> 
> After fiddling around some more with my code I found out that this seems 
to 
> have something to do 
> with the number of records the table I'm reading (here: column B112). 
Somehow,
> changing the 
> number of records for B112 changes the numbers in the error message - 
though I
> don't quite 
> understand how the number of records influences the axis intervals or 
their 
> labels, since I define 
> those explicitly...
Neither I. So I sent it to r-help maybe somebody else will know. If you 
debug code of axis.Date you find that after some computing there is this 
comparison where range is based on your input data (in your case x), and z 
is from defined at sequence of dates.

z <- z[z >= range[1] & z <= range[2]]

and this comparison results in character(0), when plotting with this 
artificial example.

plot(1:100, seq(405,410,length=100), axes=FALSE, ylim=c(405,410), 
col="red", pch=15,
type="o", ylab="metres above sea level", main="Main
Plot Title")
axis(2, at=405:410, tck=1, col="gray60")
axis.Date(1, at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month"), labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month"), tck=1, col="gray60")

I presume, that your x is from different interval of dates or it is not a 
date.

Regards
Petr

> 
> Kathi
> 
> 
> On Mon, 30 Jun 2008 11:48:43 +0200, Petr PIKAL wrote
> > Hi
> > 
> > r-help-bounces at r-project.org napsal dne 30.06.2008 11:14:48:
> > 
> > > Dear R help list
> > > 
> > > I have recently started using R to visualize time series of water
level 
> > > measurements. The code I wrote 
> > > does exactly what I want:
> > > 
> > > plot(x, a$B112, axes=FALSE, ylim=c(405,410), col="red",
pch=15,
> > > type="o", ylab="metres above sea level",
main="Main Plot Title")
> > > axis(2, at=405:410, tck=1, col="gray60")
> > > axis.Date(1, at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
> > > by="month"),
labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"), 
> > > by="month"), tck=1, col="gray60")
> > > 
> > > Now I wanted to shift the data visualized by 6 months, so I
replaced
> > > "2004-01-01" by "2004-07-01" 
> > > and "2008-06-01" by "2008-12-01". Instead of
the desired plot, I get
an 
> > error 
> > > message stating 
> > > (forgive the perhaps faulty translation into English, I'm
working on
a 
> > German 
> > > version of R):
> > > 
> > > mistake in axis(side, at = z, labels = labels, ...) : 
> > >   length of 'at' and 'labels' different, 50 != 54
> > 
> > Those two calls have different length
> > 
> > at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"), by="month")
> > labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"), by="month")
> > 
> > you can try it by
> > 
> > length(seq(...))
> > 
> > could not there be some typo in your call?
> > 
> > Regards
> > 
> > Petr
> > 
> > > 
> > > What have I done wrong? Thank you very much for your help!
> > > 
> > > Katharina Dubach
> > > 
> > > ______________________________________________
> > > 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.
> 
> 
> --
> DropNet AG - Das Unternehmen fuer Ihren Internet-Auftritt!
> 
>

Hi

"Kathi" <kathi at dropnet.ch> napsal dne 01.07.2008 18:48:47:
> On Tue, 1 Jul 2008 14:33:12 +0200, Petr PIKAL wrote
> > "Kathi" <kathi at dropnet.ch> napsal dne 01.07.2008
13:39:18:
> > 
> > > Thanks, Petr. 
> > > 
> > > After fiddling around some more with my code I found out that
this
seems 
> > to 
> > > have something to do 
> > > with the number of records the table I'm reading (here:
column
B112). 
> > Somehow,
> > > changing the 
> > > number of records for B112 changes the numbers in the error
message
- 
> > though I
> > > don't quite 
> > > understand how the number of records influences the axis
intervals
or 
> > their 
> > > labels, since I define 
> > > those explicitly...
> > 
> > Neither I. So I sent it to r-help maybe somebody else will know. If 
> > you debug code of axis.Date you find that after some computing there 
> > is this comparison where range is based on your input data (in your 
> > case x), and z is from defined at sequence of dates.
> > 
> > z <- z[z >= range[1] & z <= range[2]]
> > 
> > and this comparison results in character(0), when plotting with this 
> > artificial example.
> > 
> > plot(1:100, seq(405,410,length=100), axes=FALSE, ylim=c(405,410), 
> > col="red", pch=15,
> > type="o", ylab="metres above sea level",
main="Main Plot Title")
> > axis(2, at=405:410, tck=1, col="gray60")
> > axis.Date(1, at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
> > by="month"), labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
> > by="month"), tck=1, col="gray60")
> > 
> > I presume, that your x is from different interval of dates or it is 
> > not a date.
> 
> My data comes from a groundwater monitoring program. Once a month the 
water surface is 
> measured in some 170 stations, and I've been using R to visualize these
> measurements. In this 
> particular case, the water table ranges between approximately 406 and 
408 
> metres above sea level, 
> hence the y axis interval between 405 and 410. 
> The values of my column x are dates of the format YYYY-MM-DD. If 
something 
> were wrong there, 
> then I guess I would not be able to plot my data at all. But using the 
limits 
> of 2004-01-01 and 
> 2008-06-01, I can plot all the timelines for my 170 measuring stations 
without
> any problem. But 
> since it's now July, I wanted to shift the view by half a year. So I 
used 
> "search and replace" in my code 
> to change to 2004-07-01 and 2008-12-01 (plus six months in both cases). 
That's
> when I got the 
> error. I almost have a feeling that R doesn't like the
"empty" part of
the 
> graph for July-December...  I 
> don't understand why this happens, but maybe it has something to do
with
the 
> comparison of ranges 
> you mentioned.
OK, It seems that you are right. Maybe you could add some expected x 
date/time values so that x axis will have no NA values. 

x<-seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),by="month")
y <- seq(405,410,length=54)
y[50:54] <-NA
plot(x, y, axes=FALSE, ylim=c(405,410),col="red", pch=15,
type="o", ylab="metres above sea level", main="Main
Plot Title")
axis(2, at=405:410, tck=1, col="gray60")
axis.Date(1, at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month"), labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month"), tck=1, col="gray60")

as you see, then everything works. However I think that it is pretty close 
to bug in axis.Date, maybe somebody can enlighten us both :-)

Regards
Petr

> 
> Thanks for all your help!
> 
> Kathi
> 
> > 
> > Regards
> > Petr
> > 
> > > 
> > > Kathi
> > > 
> > > 
> > > On Mon, 30 Jun 2008 11:48:43 +0200, Petr PIKAL wrote
> > > > Hi
> > > > 
> > > > r-help-bounces at r-project.org napsal dne 30.06.2008
11:14:48:
> > > > 
> > > > > Dear R help list
> > > > > 
> > > > > I have recently started using R to visualize time
series of
water 
> > level 
> > > > > measurements. The code I wrote 
> > > > > does exactly what I want:
> > > > > 
> > > > > plot(x, a$B112, axes=FALSE, ylim=c(405,410),
col="red", pch=15,
> > > > > type="o", ylab="metres above sea
level", main="Main Plot Title")
> > > > > axis(2, at=405:410, tck=1, col="gray60")
> > > > > axis.Date(1, at=seq(as.Date("2004-01-01"), 
as.Date("2008-06-01"), 
> > > > > by="month"),
labels=seq(as.Date("2004-01-01"),
> > as.Date("2008-06-01"), 
> > > > > by="month"), tck=1, col="gray60")
> > > > > 
> > > > > Now I wanted to shift the data visualized by 6 months,
so I
replaced
> > 
> > > > > "2004-01-01" by "2004-07-01" 
> > > > > and "2008-06-01" by "2008-12-01".
Instead of the desired plot, I
get 
> > an 
> > > > error 
> > > > > message stating 
> > > > > (forgive the perhaps faulty translation into English,
I'm
working on 
> > a 
> > > > German 
> > > > > version of R):
> > > > > 
> > > > > mistake in axis(side, at = z, labels = labels, ...) : 
> > > > >   length of 'at' and 'labels'
different, 50 != 54
> > > > 
> > > > Those two calls have different length
> > > > 
> > > > at=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"), by="month")
> > > > labels=seq(as.Date("2004-01-01"),
as.Date("2008-06-01"),
by="month")
> > > > 
> > > > you can try it by
> > > > 
> > > > length(seq(...))
> > > > 
> > > > could not there be some typo in your call?
> > > > 
> > > > Regards
> > > > 
> > > > Petr
> > > > 
> > > > > 
> > > > > What have I done wrong? Thank you very much for your
help!
> > > > > 
> > > > > Katharina Dubach
> > > > > 
> > > > > ______________________________________________
> > > > > 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.
> > > 
> > > 
> > > --
> > > DropNet AG - Das Unternehmen fuer Ihren Internet-Auftritt!
> > > 
> > >
> 
> 
> --
> DropNet AG - Das Unternehmen fuer Ihren Internet-Auftritt!
> 
>