[R-sig-Geo] Coordinates tolerance ERROR

[Bede-Fazekas Ákos]

Hello Gafarou,

(as I answered your question previously in maxent using googlegroups.com...) 
the error message means that the points stored in Locations.csv are not 
in a regular grid, i.e., the distances between them are not the same. 
Although you can increase the tolerance parameter to eliminate the error 
message, this error usually indicates a deeper problem with the data 
that can not be solved (just hidden) by the increased tolerance. Maybe 
the points form a regular grid in another projection, so before trying 
to cast your SpatialPointsDataFrame to SpatialGridDataFrame with 
gridded<-(), you should spTransform() it to the adequate CRS. Also you 
should check whether the data.frame 'ForMapping' contains all the needed 
X-Y pairs. If the following gives you FALSE, it may indicate the problem:
nrow(ForMapping) == length(unique(ForMapping$X)) * 
length(unique(ForMapping$X))
I would also give a chance to raster::rasterFromXYZ().
Please send us a reproducible example (e.g. the original Locations.csv) 
to let us reproduce the error and understand its reason.

HTH,
Ákos Bede-Fazekas

2021.02.10. 14:38 keltezéssel, Gafarou AGOUNDE írta:
> Hi,
> I am facing this error when running this code bellow;
>
> suggested tolerance minimum: 0.662921
> Error in points2grid(points, tolerance, round) :
>    dimension 1: coordinate intervals are not constant
>
> What does this error mean and how to fix it?
> In fact, the Locations.csv file contains just two columns respectively X and Y in decimal degrees (e.g. X=2.07656	Y=7.08511).
> The error occurs when executing the last row.
>
> Here is the code:
> ForMapping <- read.csv("Locations.csv")
> str(ForMapping)
> length(PredictedAbundance) == length(ForMapping$X)
> ForMapping$PredictedAbundance <- PredictedAbundance
> coordinates(ForMapping) <- ~ X + Y
> gridded(ForMapping) <- TRUE
>
> Your help will be very appreciated..........!
>
> Sent from Mail for Windows 10
>
>
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>
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