spatial analysis - spgrid error - "block should be at least 1"

[Karen H]

I am trying to conduct spatial point pattern analyses in Stata, and am receiving an error while trying to use the command: spgrid in Stata SE v12.
The error reads: "block should be at least 1" r(498)

Here is my code - the error appears when I run the spgrid command:

shp2dta using StudyAreaBoundaryPolygon, database(studyarea) coordinates(coords) replace

use coords.dta, clear
gen id = _n
spmap using coords.dta, id(id) fcolor(eggshell) split
save coords, replace

spgrid using coords.dta, resolution(w500) dots compress unit(meters) cells("cells.dta") ///
points("points.dta") mapid(spgrid_mapid) replace


I can't figure out what is wrong… the spmap command correctly draws my study area boundary (which actually consists of 3 polygons) and when I try to use spgrid to generate a two-dimensional grid, the error appears.

The dataset "coords.dta" contains 4 variables, 1 is basically _n, then there are X and Y coordinates, and the final variable indicates which polygon the coordinates belong to (1, 2, or 3).

Any ideas?

I'd like to continue on and use 'spkde' after I create the grid, but am stuck at this step with this error.

Appreciate any help or ideas…
~Karen

[Karen H]

My problem was with the "resolution" option… I specified it in meters, but my coordinates were in lat/long. Problem resolved.

[Rafaella Stradiotto]

Hi Karen,
You're working with spatial econometrics, right?
Actually, you know give me some idea about how to import weight matrix with format .gwt in STATA?

Thank you.

[Surendra Karki]

Hi Karen, what code did you replaced with, can you elaborate a bit more?

[Patricio Mosquera]

Hi Karen and other members,

I have the same problem. Stata displays the following message


-> Setting up full grid...
block should be at least 1



I think that I have coordinates in my data (it shows for _X _Y the following -82.028211 9.1304977). I Would appreciate if you could explain us, how you solve it?

Thanks

[Santiago Rodrigo Frasseren]

Hello everybody. I have had the same problem and I could solve it. Just remove "unit" and "resolution" options and use xdim or ydim. Example:

spgrid using "coords.dta", xdim(100) ///
cells("Cells.dta") ///
points("Points.dta") replace ///
dots compress