[R] time series with quality codes
list(...), I am working with environmental time series (eg rainfall, stream flow) that have attached quality codes for each data point. The quality codes have just a few factor levels, like good, suspect, poor, imputed. I use the quality codes in plots and summaries. They are carried through when a time series is aggregated to a longer time-step, according to rules like worst, median or mode. I need to support time steps of anything from hours to years. I can assume the data are regular time series -- they might be irregular initially but could be 'regularized'. But I would want to plot irregular time series along with regular ones. So far I have been using a data frame with a POSIXct column, a numeric column and a factor column. However I would like to use zoo instead, because of its many utility functions and easy conversion to ts. Is there any prospect of zoo handling such numeric + factor data? Other suggestions on elegant ways to do it are also welcome. Felix -- Felix Andrews / 安福立 PhD candidate Integrated Catchment Assessment and Management Centre The Fenner School of Environment and Society The Australian National University (Building 48A), ACT 0200 Beijing Bag, Locked Bag 40, Kingston ACT 2604 http://www.neurofractal.org/felix/ xmpp:[EMAIL PROTECTED] 3358 543D AAC6 22C2 D336 80D9 360B 72DD 3E4C F5D8 __ R-help@stat.math.ethz.ch 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.
Re: [R] time series with quality codes
On Thu, 16 Aug 2007, Felix Andrews wrote: list(...), I am working with environmental time series (eg rainfall, stream flow) that have attached quality codes for each data point. The quality codes have just a few factor levels, like good, suspect, poor, imputed. I use the quality codes in plots and summaries. They are carried through when a time series is aggregated to a longer time-step, according to rules like worst, median or mode. I need to support time steps of anything from hours to years. I can assume the data are regular time series -- they might be irregular initially but could be 'regularized'. But I would want to plot irregular time series along with regular ones. So far I have been using a data frame with a POSIXct column, a numeric column and a factor column. However I would like to use zoo instead, because of its many utility functions and easy conversion to ts. Is there any prospect of zoo handling such numeric + factor data? Other suggestions on elegant ways to do it are also welcome. There is some limited support for this in zoo. You can do z - zoo(myfactor, myindex) and work with it like a zoo series and then coredata(z) will recover a factor. However, you cannot bind this to other series without losing the factor structure. At least not in a plain zoo series. But you can do df - merge(z, Z, retclass = data.frame) where every column of the resulting data.frame is a univariate zoo series. The final option would be to just have a data.frame as usual and put your data/index into one column. But then it's more difficult to leverage zoo's functionality. I would like to have more support for things like this, but currently this is what we have. Best, Z Felix -- Felix Andrews / 安福立 PhD candidate Integrated Catchment Assessment and Management Centre The Fenner School of Environment and Society The Australian National University (Building 48A), ACT 0200 Beijing Bag, Locked Bag 40, Kingston ACT 2604 http://www.neurofractal.org/felix/ xmpp:[EMAIL PROTECTED] 3358 543D AAC6 22C2 D336 80D9 360B 72DD 3E4C F5D8 __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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.
Re: [R] time series with quality codes
In addition, we could create a function to.df which converts a zoo
object to a data frame assuming that any column that only contains
1:nlevels is a factor with the indicated level names. Use to.df just
before plotting:
library(zoo)
set.seed(1)
f - zoo(factor(sample(3, 10, replace = TRUE)))
x - zoo(rnorm(10))
y - zoo(rnorm(10))
z - merge(x, y, f)
to.df - function(z, levels = letters[1:3], time = FALSE) {
zz - as.data.frame(z)
for(i in ncol(zz))
if (all(zz[,i] %in% seq_along(levels)))
z[,i] - factor(levels[z[,i]])
if (time) cbind(index = index(z), zz) else zz
}
library(lattice)
xyplot(y ~ x | f, data = to.df(z))
On 8/16/07, Achim Zeileis [EMAIL PROTECTED] wrote:
On Thu, 16 Aug 2007, Felix Andrews wrote:
list(...),
I am working with environmental time series (eg rainfall, stream flow)
that have attached quality codes for each data point. The quality
codes have just a few factor levels, like good, suspect, poor,
imputed. I use the quality codes in plots and summaries. They are
carried through when a time series is aggregated to a longer
time-step, according to rules like worst, median or mode.
I need to support time steps of anything from hours to years. I can
assume the data are regular time series -- they might be irregular
initially but could be 'regularized'. But I would want to plot
irregular time series along with regular ones.
So far I have been using a data frame with a POSIXct column, a numeric
column and a factor column. However I would like to use zoo instead,
because of its many utility functions and easy conversion to ts. Is
there any prospect of zoo handling such numeric + factor data? Other
suggestions on elegant ways to do it are also welcome.
There is some limited support for this in zoo. You can do
z - zoo(myfactor, myindex)
and work with it like a zoo series and then
coredata(z)
will recover a factor. However, you cannot bind this to other series
without losing the factor structure. At least not in a plain zoo series.
But you can do
df - merge(z, Z, retclass = data.frame)
where every column of the resulting data.frame is a univariate zoo series.
The final option would be to just have a data.frame as usual and put your
data/index into one column. But then it's more difficult to leverage zoo's
functionality.
I would like to have more support for things like this, but currently this
is what we have.
Best,
Z
Felix
--
Felix Andrews / ��
PhD candidate
Integrated Catchment Assessment and Management Centre
The Fenner School of Environment and Society
The Australian National University (Building 48A), ACT 0200
Beijing Bag, Locked Bag 40, Kingston ACT 2604
http://www.neurofractal.org/felix/
xmpp:[EMAIL PROTECTED]
3358 543D AAC6 22C2 D336 80D9 360B 72DD 3E4C F5D8
__
R-help@stat.math.ethz.ch 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.
__
R-help@stat.math.ethz.ch 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.
__
R-help@stat.math.ethz.ch 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.
