[R-sig-Geo] spacetime stConstruct gives wrong dimensions for long table

[Edzer Pebesma]

Dan, I'm moving this from r-help to r-sig-geo:

On 06/24/2015 11:29 AM, Bebber, Dan wrote:
> I have a large spatiotemporal database (131 spatial locations, 9 years of
> daily weather data) in long table format which I would like to convert to
> an ST object.
> 
>> head(tempmean)
>            site  lat    lon  alt                              var year mth
> day value       date doy numdate
> 518941 27015260 6.02 -75.37 1680 AVERAGE DAILY TEMPERATURE VALUES 2006   1
>   1  16.9 2006-01-01 001   13149
> 518942 27015260 6.02 -75.37 1680 AVERAGE DAILY TEMPERATURE VALUES 2006   1
>   2  16.4 2006-01-02 002   13150
> 518943 27015260 6.02 -75.37 1680 AVERAGE DAILY TEMPERATURE VALUES 2006   1
>   3  16.9 2006-01-03 003   13151
> 518944 27015260 6.02 -75.37 1680 AVERAGE DAILY TEMPERATURE VALUES 2006   1
>   4  16.1 2006-01-04 004   13152
> 518945 27015260 6.02 -75.37 1680 AVERAGE DAILY TEMPERATURE VALUES 2006   1
>   5  16.6 2006-01-05 005   13153
> 518946 27015260 6.02 -75.37 1680 AVERAGE DAILY TEMPERATURE VALUES 2006   1
>   6  16.7 2006-01-06 006   13154
> 
> 
> The data.frame is ‘ragged’, i.e. not all sites are represented by all
> dates, and there are some NA values in the data.
> 
> I took a subset of the data (4 sites, 31 days in January 2006, for which
> all site/date combinations are present) and tried
> 
>> st <- stConstruct(tempmean, 3:2, 10)
>> summary(st)
> Object of class STIDF
>  with Dimensions (s, t, attr): (124, 124, 9)
> [[Spatial:]]
> Object of class SpatialPoints
> Coordinates:
>        min    max
> lon -76.45 -73.11
> lat   2.11   7.07
> Is projected: NA 
> proj4string : [NA]
> Number of points: 124
> [[Temporal:]]
>      Index              timeIndex
>  Min.   :2006-01-01   Min.   :  1.00
>  1st Qu.:2006-01-08   1st Qu.: 31.75
>  Median :2006-01-16   Median : 62.50
>  Mean   :2006-01-16   Mean   : 62.50
>  3rd Qu.:2006-01-24   3rd Qu.: 93.25
>  Max.   :2006-01-31   Max.   :124.00
> 
> 
> This is incorrect: There should be 4 spatial dimensions and 31 timepoints.

STIDF is essentially the long table form, it does not identify identical
space/time values.

Try:

dim(as(st, "STSDF"))

and

dim(as(st, "STFDF"))

after you figure out what these classes try to represent from the
package vignette / JSS paper.

> 
> What am I doing wrong?
> 
> Thanks,
> Dan
> 
> Dr Dan Bebber
> Senior Research Fellow
> Biosciences
> University of Exeter
> 
> 
> 
> 

-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi),  University of Münster,
Heisenbergstraße 2, 48149 Münster, Germany; +49 251 83 33081
Journal of Statistical Software:   http://www.jstatsoft.org/
Computers & Geosciences:   http://elsevier.com/locate/cageo/
Spatial Statistics Society http://www.spatialstatistics.info

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