Hi, Could any one point me to the projection, and parameters if necessary, that would show each country/continent with it's area accurately refelcted on the plot? E.g. aitoff vs. albers vs. bonne vs. cylequalearea vs. guyou - they don't all look the same to mee but some of the documentations suggests they are equal area? Of course this isn't my field, so I am largely guessing and am prorbably making some naive assumptions :) I'm pretty sure this is on the R-help archive but I don't seem to be able to access most of the posts that the search returns - I keep getting a 'file not found' page... TIA Mark
On Thu, 4 Mar 2004, Mark Van De Vyver wrote:> Hi, > Could any one point me to the projection, and parameters if necessary, that > would show each country/continent with it's area accurately refelcted on the > plot? E.g. aitoff vs. albers vs. bonne vs. cylequalearea vs. guyou - they > don't all look the same to mee but some of the documentations suggests they > are equal area? Of course this isn't my field, so I am largely guessing and > am prorbably making some naive assumptions :) > I'm pretty sure this is on the R-help archive but I don't seem to be able to > access most of the posts that the search returns - I keep getting a 'file > not found' page...One of the best online resources is the collection of documentation links at: http://www.remotesensing.org/proj The manual has figures with examples of projections. GMT also has projection documentation: http://gmt.soest.hawaii.edu/ The printed resources, which are well worth consulting, are: John P. Snyder (1987) Map projections - a working manual, USGS professional paper 1395; Lev M. Bugayevskiy and John P. Snyder (1995) Map projections - a reference manual (London, Taylor & Francis). The field is quite extensive, and most often a choice that is "right" for one use will not be for another. Even measuring area accurately in the field is bad enough, but representing it on a flat 2D surface has challenged people for a long time and will certainly continue to do so (cartography is an interesting part of graphic visualisation!).> TIA > Mark > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Breiviksveien 40, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93 e-mail: Roger.Bivand at nhh.no
Hi Roger, thanks very much for your help. I'll follow those references up. Regards Mark -----Original Message----- From: Roger Bivand [mailto:Roger.Bivand at nhh.no] Sent: Thu 04-Mar-04 8:18 PM To: Mark Van De Vyver Cc: r-help at stat.math.ethz.ch Subject: Re: [R] Accurate area map projections On Thu, 4 Mar 2004, Mark Van De Vyver wrote:> Hi, > Could any one point me to the projection, and parameters if necessary, that > would show each country/continent with it's area accurately refelcted on the > plot? E.g. aitoff vs. albers vs. bonne vs. cylequalearea vs. guyou - they > don't all look the same to mee but some of the documentations suggests they > are equal area? Of course this isn't my field, so I am largely guessing and > am prorbably making some naive assumptions :) > I'm pretty sure this is on the R-help archive but I don't seem to be able to > access most of the posts that the search returns - I keep getting a 'file > not found' page...One of the best online resources is the collection of documentation links at: http://www.remotesensing.org/proj The manual has figures with examples of projections. GMT also has projection documentation: http://gmt.soest.hawaii.edu/ The printed resources, which are well worth consulting, are: John P. Snyder (1987) Map projections - a working manual, USGS professional paper 1395; Lev M. Bugayevskiy and John P. Snyder (1995) Map projections - a reference manual (London, Taylor & Francis). The field is quite extensive, and most often a choice that is "right" for one use will not be for another. Even measuring area accurately in the field is bad enough, but representing it on a flat 2D surface has challenged people for a long time and will certainly continue to do so (cartography is an interesting part of graphic visualisation!).> TIA > Mark > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Breiviksveien 40, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93 e-mail: Roger.Bivand at nhh.no
Mark Van De Vyver
2004-Mar-17 20:31 UTC
[R] Substitute for xlim and usr in boxplot(...) & bxp(...)?
Hi, Could anyone hint at how to set the x axis plot range in boxplot/bxp? The docs are clear that usr and xlim are not passed through/down TIA Mark
Just catching up on r-help, ignore if you have already have moved on ... I almost always use the Lambert azimuthal equal-area projection (called "azequalarea" in the maps package). Unless the study area is unusually elongated this projection will give good performance. In fact, it has lower average distortion (but not lower extreme distortion) than the standard projection used for the conterminous US, the Albers conical equal-area. See: Kimerling AJ, Overton WS, White D. 1995. Statistical comparison of map projection distortions within irregular areas. Cartography and Geographic Information Systems 22(3):205-221, (pdf available at http://www.epa.gov/wed/pages/staff/white/pubs.htm) Denis White US EPA, 200 SW 35th St, Corvallis, Oregon, 97333 USA voice: 541.754.4476, email: white.denis at epa.gov web: www.epa.gov/wed/pages/staff/white/> Hi, > Could any one point me to the projection, and parameters if necessary,that> would show each country/continent with it's area accurately refelctedon the> plot? E.g. aitoff vs. albers vs. bonne vs. cylequalearea vs. guyou -they> don't all look the same to mee but some of the documentations suggeststhey> are equal area? Of course this isn't my field, so I am largelyguessing and> am prorbably making some naive assumptions :) > I'm pretty sure this is on the R-help archive but I don't seem to beable to> access most of the posts that the search returns - I keep getting a'file> not found' page... > TIA > Mark