<HTML>
<HEAD>
<TITLE>Region setting correction</TITLE>
</HEAD>
<BODY>
<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>I wanted to correct a few things I just said about region settings.<BR>
<BR>
</SPAN></FONT><OL><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>If you run g.region from the command line—either with arguments (e.g., g.region –p) or without arguments so that it starts one of the autogenerated GUI dialogs—it sets and/or reports on the values in the WIND file. This is the way I described it a few minutes ago.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>BUT, if you run g.region from the menu, there is anomalous behavior that may be the cause of considerable and repeated confusion. G.region started from the menus will REPORT (i.e., with –p set) on the region of the currently active display window (i.e., whichever display currently has the focus). If you try to set something with g.region run from the menu, it seems to have NO EFFECT on a display OR on the WIND file.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>However, if you set something from a g.region dialog run from the menu AND select ‘zoom to current region’ from the menu button on the toolbar, the display will match the g.region settings—even though this is NOT in the WIND file.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>If you set something from a g.region dialog started from the command line (or issue a g.region command with arguments) and select ‘zoom to current region’ from the menu button on the toolbar, it will have NO EFFECT on the display zooming.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>If you zoom interactively in a map display and select ‘set current region (WIND file) to match display’, this WILL change the WIND file to match the display (check by running g.region –p from the command line). At this point, it can insert some rounding error in resetting the WIND file to match the display. I think this is what Maciek is seeing. I tried changing to a g.region –a (align to current region) and it had no effect on this rounding error.<BR>
</SPAN></FONT></OL><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'><BR>
The map display interactive zooming and zoom menu button are behaving as they should. <BR>
<BR>
</SPAN></FONT><OL><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Interactive zooming affects a dynamic region ONLY for that display and DOES NOT affect the WIND file
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Selecting ‘zoom to current region’ DOES change the display to match the settings of g.region run from the menu—but NOT from the command line.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Selecting ‘set current region (WIND file)...’ DOES change the WIND file to match the display.<BR>
</SPAN></FONT></OL><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'><BR>
BUT (and a very confusing one at that), g.region run from the command line and g.region run from the menus do NOT always behave the same way with regard to the interactive zooming in a display. I have no idea why this is so. Maybe someone else can enlighten me. <BR>
<BR>
Michael<BR>
__________________________________________<BR>
Michael Barton, Professor of Anthropology<BR>
School of Human Evolution & Social Change <BR>
Center for Social Dynamics & Complexity<BR>
Arizona State University<BR>
<BR>
phone: 480-965-6213<BR>
fax: 480-965-7671<BR>
www: <a href="http://www.public.asu.edu/~cmbarton">http://www.public.asu.edu/~cmbarton</a> <BR>
<BR>
</SPAN></FONT>
</BODY>
</HTML>