R help - Feb 2013 - Plotting multiple Zoo object lines

I would like to plot multiple zoo object lines on one plot. These are time
series of temperatures derived from different sampling regimes (one is
sub-hourly, and the other is bi-weekly). I understand that they need to be
indexed in the same way to be plotted together, and so took my two zoo objects
(Named DataNOAAZOO and NightTemps20m and transformed into similar daily means
with this code:

DailyNightTemps_20m = aggregate(NightTemps_20m, as.Date(time(NightTemps_20m)),
mean)
DailyNightTemps_NOAA = aggregate(DataNOAAZOO$SST, as.Date(time(DataNOAAZOO)),
mean)

One object now has ~4000 entries and the other ~1000 (one is every day and the
other bi-weekly) but they are now on the same daily index (at least I believe
they are, from my reading). Therefor I think they should plot together with this
code:

plot(DailyNightTemps_20m)
lines (DailyNightTemps_NOAA, col = "red")

(This is directly from the zoo instructions, which state: 
## univariate plotting
x <- zoo(rnorm(5), x.Date)
x2 <- zoo(rnorm(5, sd = 0.2), x.Date)
plot(x)
lines(x2, col = 2) )

But the second one does not show up at all and I get no error message.

I will be doing a similar operation with Monthly and Annual Means, and also
similar plots with other parameters in the zoo (derived differences), so I want
so solve this issue before moving on to the other variables. I did some reading
before posting and tried various solutions, but I still cannot figure out why
the basic instructions above do not work.

I know this is a basic question, with a probably obvious answer, but it kept me
up all night so thanks for any assistance. Ben Neal

On Wed, Feb 27, 2013 at 8:06 AM, Ben Neal <bneal at spg.ucsd.edu>
wrote:
> I would like to plot multiple zoo object lines on one plot. These are time
series of temperatures derived from different sampling regimes (one is
sub-hourly, and the other is bi-weekly). I understand that they need to be
indexed in the same way to be plotted together, and so took my two zoo objects
(Named DataNOAAZOO and NightTemps20m and transformed into similar daily means
with this code:
>
> DailyNightTemps_20m = aggregate(NightTemps_20m,
as.Date(time(NightTemps_20m)), mean)
> DailyNightTemps_NOAA = aggregate(DataNOAAZOO$SST,
as.Date(time(DataNOAAZOO)), mean)
>
> One object now has ~4000 entries and the other ~1000 (one is every day and
the other bi-weekly) but they are now on the same daily index (at least I
believe they are, from my reading). Therefor I think they should plot together
with this code:
>
> plot(DailyNightTemps_20m)
> lines (DailyNightTemps_NOAA, col = "red")
>
> (This is directly from the zoo instructions, which state:
> ## univariate plotting
> x <- zoo(rnorm(5), x.Date)
> x2 <- zoo(rnorm(5, sd = 0.2), x.Date)
> plot(x)
> lines(x2, col = 2) )
>
> But the second one does not show up at all and I get no error message.
>
> I will be doing a similar operation with Monthly and Annual Means, and also
similar plots with other parameters in the zoo (derived differences), so I want
so solve this issue before moving on to the other variables. I did some reading
before posting and tried various solutions, but I still cannot figure out why
the basic instructions above do not work.
>
> I know this is a basic question, with a probably obvious answer, but it
kept me up all night so thanks for any assistance. Ben Neal
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