R help - Apr 2006 - persp plot increasing 'x' and 'y' values expected

hello,

i do the following in order to get an persp-plot

x<-c(2,2,2,2,2,2,3,3,3,3)
y<-c(41,41,83,83,124,166,208,208,208,208)
z<-c(90366,90366,92240,92240,92240,96473,100995,100995,100995,100995)
x<-data$x
y<-data$y
z<-matrix(data$z,length(y),length(x))
persp(x,y,z, col="gray")

but i always get the error message increasing 'x' and 'y' values
expected, but i think my data values are already increasing, what is wrong?

best regards
andreas

Hi,
yes, your x and y are increasing but the (x,y) coordinates are not unique.
Looks like some measurements are redundant in your input.
Michael
> hello,
>
> i do the following in order to get an persp-plot
>
> x<-c(2,2,2,2,2,2,3,3,3,3)
> y<-c(41,41,83,83,124,166,208,208,208,208)
> z<-c(90366,90366,92240,92240,92240,96473,100995,100995,100995,100995)
> x<-data$x
> y<-data$y
> z<-matrix(data$z,length(y),length(x))
> persp(x,y,z, col="gray")
>
> but i always get the error message increasing 'x' and 'y'
values
> expected, but i think my data values are already increasing, what is wrong?
>
> best regards
> andreas
>
> ______________________________________________
> R-help at 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

voodooochild at gmx.de wrote:
> hello,
> 
> i do the following in order to get an persp-plot
> 
> x<-c(2,2,2,2,2,2,3,3,3,3)
> y<-c(41,41,83,83,124,166,208,208,208,208)
> z<-c(90366,90366,92240,92240,92240,96473,100995,100995,100995,100995)
> x<-data$x
> y<-data$y
> z<-matrix(data$z,length(y),length(x))
> persp(x,y,z, col="gray")
> 
> but i always get the error message increasing 'x' and 'y'
values
> expected, but i think my data values are already increasing, what is wrong?

I'm not sure what your data$x, data$y, data$z are (but I can guess).
Why do you think that your x is *increasing*? Is x[i+1] > x[i]?
Does diff(x) yield only positive values?

What kind of a perspective plot do you expect? You seem to have only
5 unique points.

Peter Ehlers

> 
> best regards
> andreas
>

On Fri, 5 May 2006, Rick Bilonick wrote:
> Has anyone else noticed that gstat no longer handles 1-D data?
> 
Thanks for this report, writing directly to the package maintainer or the 
R-sig-geo list might have been a better choice than R-help

The problem does exist, but can be worked round by inserting a constant 
second dimension:

library(gstat)
data(meuse)
meuse$constY <- rep(1,nrow(meuse))
coordinates(meuse) = ~ x + constY
variogram(zinc ~ 1, data=meuse)

also leaving out the location formula, and using the coordinates in the 
SpatialPointsDataFrame object

Roger
> > library(gstat)
> > coordinates(pm.df) <- ~x
> Error in validObject(.Object) : invalid class "SpatialPoints"
object:
> spatial.dimension should be 2 or more
> > variogram(pm~1,~x,data=pm.df)
> Error in validObject(.Object) : invalid class "SpatialPoints"
object:
> spatial.dimension should be 2 or more
> 
> The variogram call used to work. It stopped working when I upgraded to
> the latest version of gstat.
> 
> Rick B.
> 
> ______________________________________________
> R-help at 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
> 
-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no