Question spdep package - extending nb object
Dear Roger, Thank you very much for your reply. It is kind of a spatial panel model, but I have only one time series. To describe it differently: The dependent variable consists of twenty blocks with averaged data. Each block is related to one season and one out of five time slots (that is why I have 20 blocks - 4 seasons times 5 time slots). And each block of data refers to the very same grid, i.e. the first entry of the first block corresponds to the same call as the first entry of all the other blocks, the second entries correspond to the second cell etc. The grid is of hectare resolution, i.e. 100 x 100m (one could see this as similar to post codes). Therefore, nb2blocknb() sounds interesting, even though I do not really have ?location-less observations?, but just observations with different attributes (season and time). Would it work if my ?ID? argument is built in such a way that it repeats 19 times the identification tags of the first block? For example: rep(seq(from = 1, to = m, by = 1),19) , where m is the number of cells in my grid? Best, Raphael
Am 17.05.2019 um 14:13 schrieb Roger Bivand <Roger.Bivand at nhh.no>: On Thu, 16 May 2019, Raphael Mesaric via R-sig-Geo wrote:
Dear all, I am working on a spatial regression model which is built in such a way that the dependent variable consists of n blocks of multiple entries, and each block is referring to the same spatial grid. In order to run the lagsarlm() function or the errsarlm() function, I now need to extend my initial nb object from one grid to n grids. In other words, I need the nb object to be repeated n times. However, so far I did not find a way to do this properly. I tried to just replicate the nb object by repeating the entries of the neighbours list and the weights list, respectively. dnn800_3w$neighbours <- rep(dnn800_3w$neighbours,20) dnn800_3w$weights <- rep(dnn800_3w$weights,20) When I do this, I get the following error message: Error in is.symmetric.nb(listw$neighbours, FALSE) : Not neighbours list Which makes sense, as the matrix is not symmetric any more due to the steps described above. However, I cannot think of a correct implementation at the moment.
Not even worth trying, as you found. Do you mean a Kronecker product, as found in spatial panel models? Or do you mean that you have blocks of observations without position that belong to upper-level objects with known position (postcodes or similar)? If the latter, look at ?spdep::nb2blocknb. Hope this clarifies, Roger
Can you help me with this issue? Any suggestions are highly appreciated. Thank you in advance. Best regards, Raphael Mesaric [[alternative HTML version deleted]]
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