Re: st: spmap to plot only points?

[Maurizio Pisati <maurizio.pisati@unimib.it>]

Dear Thomas,
you have two basic option:


1. Without -spmap-: Plot the points using -graph twoway scatter-.


2. With -spmap-: You need to create a dummy basemap that contains all the points, and then proceed as usual. Here's an example using the point dataset "Italy-Capitals.dta" distributed with -spmap-:

. * Open the point dataset of interest
. use "Italy-Capitals.dta", clear

. * Find the min and max values of the x- and y-coordinates of the points 
. summarize xcoord ycoord

    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
      xcoord |       103    758654.8    226063.8   368761.1    1279167
      ycoord |       103     4761314    288410.5    4101939    5151970

. * Create a basemap dataset representing the (approximate) minimum bounding
. * box for your set of points

. clear
. input _ID _X _Y

           _ID         _X         _Y
  1. 1 . .
  2. 1 350000 4000000
  3. 1 350000 5200000
  4. 1 1300000 5200000
  5. 1 1300000 4000000
  6. end

. sort _ID, stable
. save "mbb.dta", replace
file mbb.dta saved

. * Create a temporary master dataset containing just one location
. clear
. input id

            id
  1. 1
  2. end

. * Draw the map setting the basemap outline color to "none"
. spmap using "mbb.dta", id(id) ocolor(none) point(data("Italy-Capitals.dta") x(xcoord) y(ycoord))


Best wishes,
Maurizio
	


Il giorno 03/set/2013, alle ore 22.21, Thomas Speidel ha scritto:

> I'm using spmap (user written addon by Maurizio Pisati - 1.2.0) to plot location
> points by certain attributes. I'm wondering if it is possible, either with
> spmap or other spatial addons, to plot the points without a boundary region
> since I'm interested in the location of the points relative to each other.
> I do have a boundary shapefile which I was able to use. However, the
> boundary is too large compared to the distance among the points, thus, it
> does not convey spatial distribution.
> 
> Thanks
> 
> -- 
> Thomas Speidel



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