Re: [R] Advice on Grid Data

2006-11-24 Thread Roger Bivand
On Fri, 24 Nov 2006, Lorenzo Isella wrote:

> On 24/11/06, Roger Bivand <[EMAIL PROTECTED]> wrote:
> > On Fri, 24 Nov 2006, Lorenzo Isella wrote:
> >
> > > Dear All,
> > > I would like to automate the analysis and plotting of data taken from a 
> > > grid.
> > > Typically I deal with 2 spatial coordinates and a scalar f(x,y), but
> > > the spatial grid is not evenly spaced at all and usually given in this
> > > form:
> > > x y 
> > > f(x,y)
> > > 0.0  0.048979383  2.7659438106975056
> > > 0.0  0.044986665  2.603891585041688
> > > 0.0023807306 0.04787451   2.715949356768243
> > > 0.0  0.040993948  2.469223979694342
> > > 0.0023807306 0.043881793  2.5625191444824265
> > > 0.004761461  0.046769638  2.6629703119429022
> > > 0.0  0.03700123   2.361940994655468
> > > 0.0023807306 0.039889075  2.436480700580665
> > > 0.004761461  0.04277692   2.517958884562618
> > > 0.0071421918 0.045664765  2.606844303834078
> > > 0.0  0.060880877  3.470808435449538
> > > 0.0  0.05691371   3.1907723461238686
> > > 0.0020467786 0.059650626  3.3672237912200016
> > > 0.0  0.05294655   2.9558174712065237
> > > 0.0020467786 0.055683464  3.1075221272152054
> > > 0.004093557  0.05842038   3.268965886866726
> > > 0.0020467786 0.051716298  2.8929170062920653
> > > 0.004093557  0.054453213  3.029154848759894
> > > 0.006140336  0.057190128  3.1754081073235088
> > > 0.0  0.02473231   2.138648866573983
> > > 0.0  0.020556964  2.092324627395541
> > >
> > > I tried the image plot and lattice but unsuccessfully. Now I am
> > > reading about the sp package (
> > > http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I
> > > mainly would like a piece of advice about what tools to use and how to
> > > read and plot these data (I suppose it must be common e.g. in
> > > geography to deal with this kind of problems).
> >
> > Your data are not on a 2D grid, there are (here) 7 unique x values, but 21
> > unique y values of 21. You can treat the data as a SpatialPointsDataFrame
> > (see note in R News in 2005), but if you want to display them on an actual
> > grid, you will have to interpolate. For more ideas, perhaps try the
> > R-sig-geo mailing list.
> >
> > > Kind Regards
> > >
> > > Lorenzo
> > >
> > > __
> > > 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.
> > >
> >
> > --
> > 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: [EMAIL PROTECTED]
> >
> >
> 
> Thanks for the advice, but I hope I have not been misleading: only
> part of the grid coordinates are reported here (the whole list is very
> long).
> Does your conclusion hold anyway?


Well, if you convert your data to a SpatialPointsDataFrame, and then try 
to go to a SpatialPixelsDataFrame, you'll see if you succeed. A 
SpatialGridDataFrame requires data at all the cells in the grid, which you 
do not seem to have, so if you can get to a SpatialPixelsDataFrame, you 
will have display methods. If you look at the example on:

?"SpatialPixels-class"

and try to get to:

 data(meuse.grid)
 pts = meuse.grid[c("x", "y")]
 y = SpatialPixels(SpatialPoints(pts))
 class(y)
 y

then you should be able to do the same with your data present, see 

?"SpatialPixelsDataFrame-class"

Roger

> Cheers
> 
> Lorenzo
> 

-- 
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: [EMAIL PROTECTED]

__
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] Advice on Grid Data

2006-11-24 Thread Lorenzo Isella
On 24/11/06, Roger Bivand <[EMAIL PROTECTED]> wrote:
> On Fri, 24 Nov 2006, Lorenzo Isella wrote:
>
> > Dear All,
> > I would like to automate the analysis and plotting of data taken from a 
> > grid.
> > Typically I deal with 2 spatial coordinates and a scalar f(x,y), but
> > the spatial grid is not evenly spaced at all and usually given in this
> > form:
> > x y 
> > f(x,y)
> > 0.0  0.048979383  2.7659438106975056
> > 0.0  0.044986665  2.603891585041688
> > 0.0023807306 0.04787451   2.715949356768243
> > 0.0  0.040993948  2.469223979694342
> > 0.0023807306 0.043881793  2.5625191444824265
> > 0.004761461  0.046769638  2.6629703119429022
> > 0.0  0.03700123   2.361940994655468
> > 0.0023807306 0.039889075  2.436480700580665
> > 0.004761461  0.04277692   2.517958884562618
> > 0.0071421918 0.045664765  2.606844303834078
> > 0.0  0.060880877  3.470808435449538
> > 0.0  0.05691371   3.1907723461238686
> > 0.0020467786 0.059650626  3.3672237912200016
> > 0.0  0.05294655   2.9558174712065237
> > 0.0020467786 0.055683464  3.1075221272152054
> > 0.004093557  0.05842038   3.268965886866726
> > 0.0020467786 0.051716298  2.8929170062920653
> > 0.004093557  0.054453213  3.029154848759894
> > 0.006140336  0.057190128  3.1754081073235088
> > 0.0  0.02473231   2.138648866573983
> > 0.0  0.020556964  2.092324627395541
> >
> > I tried the image plot and lattice but unsuccessfully. Now I am
> > reading about the sp package (
> > http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I
> > mainly would like a piece of advice about what tools to use and how to
> > read and plot these data (I suppose it must be common e.g. in
> > geography to deal with this kind of problems).
>
> Your data are not on a 2D grid, there are (here) 7 unique x values, but 21
> unique y values of 21. You can treat the data as a SpatialPointsDataFrame
> (see note in R News in 2005), but if you want to display them on an actual
> grid, you will have to interpolate. For more ideas, perhaps try the
> R-sig-geo mailing list.
>
> > Kind Regards
> >
> > Lorenzo
> >
> > __
> > 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.
> >
>
> --
> 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: [EMAIL PROTECTED]
>
>

Thanks for the advice, but I hope I have not been misleading: only
part of the grid coordinates are reported here (the whole list is very
long).
Does your conclusion hold anyway?
Cheers

Lorenzo

__
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] Advice on Grid Data

2006-11-24 Thread Roger Bivand
On Fri, 24 Nov 2006, Lorenzo Isella wrote:

> Dear All,
> I would like to automate the analysis and plotting of data taken from a grid.
> Typically I deal with 2 spatial coordinates and a scalar f(x,y), but
> the spatial grid is not evenly spaced at all and usually given in this
> form:
> x y f(x,y)
> 0.0  0.048979383  2.7659438106975056
> 0.0  0.044986665  2.603891585041688
> 0.0023807306 0.04787451   2.715949356768243
> 0.0  0.040993948  2.469223979694342
> 0.0023807306 0.043881793  2.5625191444824265
> 0.004761461  0.046769638  2.6629703119429022
> 0.0  0.03700123   2.361940994655468
> 0.0023807306 0.039889075  2.436480700580665
> 0.004761461  0.04277692   2.517958884562618
> 0.0071421918 0.045664765  2.606844303834078
> 0.0  0.060880877  3.470808435449538
> 0.0  0.05691371   3.1907723461238686
> 0.0020467786 0.059650626  3.3672237912200016
> 0.0  0.05294655   2.9558174712065237
> 0.0020467786 0.055683464  3.1075221272152054
> 0.004093557  0.05842038   3.268965886866726
> 0.0020467786 0.051716298  2.8929170062920653
> 0.004093557  0.054453213  3.029154848759894
> 0.006140336  0.057190128  3.1754081073235088
> 0.0  0.02473231   2.138648866573983
> 0.0  0.020556964  2.092324627395541
> 
> I tried the image plot and lattice but unsuccessfully. Now I am
> reading about the sp package (
> http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I
> mainly would like a piece of advice about what tools to use and how to
> read and plot these data (I suppose it must be common e.g. in
> geography to deal with this kind of problems).

Your data are not on a 2D grid, there are (here) 7 unique x values, but 21
unique y values of 21. You can treat the data as a SpatialPointsDataFrame
(see note in R News in 2005), but if you want to display them on an actual
grid, you will have to interpolate. For more ideas, perhaps try the 
R-sig-geo mailing list.

> Kind Regards
> 
> Lorenzo
> 
> __
> 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.
> 

-- 
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: [EMAIL PROTECTED]

__
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] Advice on Grid Data

2006-11-24 Thread Lorenzo Isella
Dear All,
I would like to automate the analysis and plotting of data taken from a grid.
Typically I deal with 2 spatial coordinates and a scalar f(x,y), but
the spatial grid is not evenly spaced at all and usually given in this
form:
x y f(x,y)
0.0  0.048979383  2.7659438106975056
0.0  0.044986665  2.603891585041688
0.0023807306 0.04787451   2.715949356768243
0.0  0.040993948  2.469223979694342
0.0023807306 0.043881793  2.5625191444824265
0.004761461  0.046769638  2.6629703119429022
0.0  0.03700123   2.361940994655468
0.0023807306 0.039889075  2.436480700580665
0.004761461  0.04277692   2.517958884562618
0.0071421918 0.045664765  2.606844303834078
0.0  0.060880877  3.470808435449538
0.0  0.05691371   3.1907723461238686
0.0020467786 0.059650626  3.3672237912200016
0.0  0.05294655   2.9558174712065237
0.0020467786 0.055683464  3.1075221272152054
0.004093557  0.05842038   3.268965886866726
0.0020467786 0.051716298  2.8929170062920653
0.004093557  0.054453213  3.029154848759894
0.006140336  0.057190128  3.1754081073235088
0.0  0.02473231   2.138648866573983
0.0  0.020556964  2.092324627395541

I tried the image plot and lattice but unsuccessfully. Now I am
reading about the sp package (
http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I
mainly would like a piece of advice about what tools to use and how to
read and plot these data (I suppose it must be common e.g. in
geography to deal with this kind of problems).
Kind Regards

Lorenzo

__
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.