Pierre,
Tkank You for help. I solve problem whit gridded.
I have next question. How make to fit legend(scale) of plot? I use function
points().
Cheers,
Agnieszka
2010/12/9 Pierre Roudier <pierre.roudier at gmail.com>
Agnieszka,
In your code, alu.sp as no attribute because it is an output of the
spsample function - it samples spatial locations, not the data itslef.
If you look at the class of your objects, alu is a
SpatialPointsDataFrame when alu.sp is a SpatialPoints, which means it
is just a set of spatial locations, without any attached data frame.
Things will be much clearer if:
- you give us what exactly you want to achieve. What exactly do you
use this spsample function for?
- you use an embbeded data set like meuse, as I do not have your alu
data set and therefore can't reproduce your code. Just load it like
that:
data(meuse)
coordinates(meuse) <- ~x+y
Cheers,
Pierre
2010/12/10 Agnieszka Kaczmarczyk <agnes.kaczmarczyk at gmail.com>:
Hello Pierre,
Thank You for answer. It is full code? that I use;
class(alu)
names(alu)
coordinates(alu) = ~x+y
class(alu)
summary(alu)
Object of class SpatialPointsDataFrame
Coordinates:
????? min???? max
x 4384068 4393091
y 5569911 5579336
Is projected: NA
proj4string : [NA]
Number of points: 1393
Data attributes:
?? Min. 1st Qu.? Median??? Mean 3rd Qu.??? Max.
?0.0300? 0.1400? 0.3100? 0.3799? 0.5800? 1.5000
names(alu)
[1] "al"
dimensions(alu)
(alu)[1:2,]
??? coordinates?? al
1 (4384100, 5570080) 0.20
2 (4384070, 5570300) 0.15
it is ok.
alu.sp = spsample(alu, type = "regular", cellsize = c(50,50))
summary(alu.sp)
Object of class SpatialPoints
Coordinates:
?????? min???? max
x1 4384069 4393069
x2 5569950 5579300
Is projected: NA
proj4string : [NA]
Number of points: 34028
Here atrributes is missing.
I use functions;
?gridded(alu) = TRUE
Error in points2grid(points, tolerance, round, fuzz.tol) :
? dimension 1 : coordinate intervals are not constant after allowing for
numeric fuzz
In addition: Warning message:
In points2grid(points, tolerance, round, fuzz.tol) :
? grid has empty column/rows in dimension 1
?I can't solve this problem. I change to parameter function and nothing.
I tried other funciton and scheme. It Is my frist problem in R.
Agnieszka
2010/12/9 Pierre Roudier <pierre.roudier at gmail.com>
Hi Agnieszka,
This question is not easy to answer because unfortunately you gave
very few details. I assume you want to use the function gridded() on
your dataset alu.
First thing you have to do is to make your dataset a Spatial object.
This is done using the coordinates() function:
library(sp)
coordinates(alu) <- ~x+y # Again, I'm just guessing x and y are the
spatial coordinates
class(alu)
The class of alu should be "SpatialDataFrame"
If your data set is on a *regular* grid, you may want to use the
gridded() function to make alu a Grid:
gridded(alu) <- TRUE
At this point, you may have the following error:
suggested tolerance minimum: 0.142857142857143
Error in points2grid(points, tolerance, round, fuzz.tol) :
?dimension 1 : coordinate intervals are not constant
This means your data set is not regularly gridded. You may want to use
the points2grid function, which has a tolerance parameter.
If your dataset is not gridded, and you need to generate a prediction
grid (eg for kriging), I advise you to use the spsample function (see
?spsample).
hope this helps,
Pierre
2010/12/9 Agnieszka Kaczmarczyk <agnes.kaczmarczyk at gmail.com>:
Hello,
I have to gridded my data alu:
class(alu)
[1] "data.frame"
alu[1:3,1:3]
? ? ? ?x ? ? ? y ? al
1 4384104 5570084 0.20
2 4384068 5570297 0.15
3 4384111 5570551 0.08
I use function: gridded(), spsample(),points2grid(),GridTopology(),
expand.grid() ect.
I read The meuse data set: a tutorial for the gstat R package and
other
tutorial for R. I can't solve this problem. I'm interesting
geostatistic
simulation. Can you help me with my problem?
With best regards,
Agnieszka
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