Hello sir(s), Firstly I would like to thank both of you for your input in assistance me with my problems that I am facing using R aa a spatial analysis tool.
I have been trying to do this for past 6 months and have found it really challenging but quite interesting as well. I will look at the codes and try to complete my project. Sir all credits goes to both of you since you have provided timely response to my questions. If I do face any issues will try to consult again. Yours sincerely Sownal On Mon, Mar 14, 2022, 02:07 Roger Bivand <roger.biv...@nhh.no> wrote: > On Sun, 13 Mar 2022, Micha Silver wrote: > > > > > On 13/03/2022 01:41, sownal chand wrote: > >> Hello Sir/Madam, > >> > >> I am Sownal Chand, from Fiji Islands and am currently working on a > project > >> which involves spatial analysis of climate data (Temperature, rainfall, > >> etc). I have been able to write codes in R for Point interpolations of > >> these parameters but I require some assistance in mapping these raster > >> files on the southwest pacific maps. For example, a map of Fiji > Islands ( > >> > https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.pinterest.com%2Fpin%2F740982944911004875&data=04%7C01%7CRoger.Bivand%40nhh.no%7C3d492fafcd7247d2090e08da04cde59b%7C33a15b2f849941998d56f20b5aa91af2%7C0%7C0%7C637827580063300234%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=5xNJDee6Glb%2FW7MCkO8biDzHl1%2Bv5hc%2FBsU%2FmO9neLE%3D&reserved=0 > >> ) and I am facing some > >> difficulties in making these plots. > >> > >> I hope that some expert would be willing to help me with this and the > >> map's > >> CRS setting is a bit confusing and I am a beginner in this area ( i. e, > >> spatial analysis using R). I have been looking at tutorials and codes > to > > > > > > There are tons of online resources. You could, for example, refer to: > > > > > https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgeocompr.robinlovelace.net%2F&data=04%7C01%7CRoger.Bivand%40nhh.no%7C3d492fafcd7247d2090e08da04cde59b%7C33a15b2f849941998d56f20b5aa91af2%7C0%7C0%7C637827580063300234%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=08BU9QbKjLNh5TkKeu38etqzU%2FOysx7fqsGoVq3kImw%3D&reserved=0 > > > > > >> crop country boundaries and shapefiles and still found lots of errors > in > >> my > >> codes. > > > > > > You have raised a few different questions. Would you mind to post what > you > > have done so far, and point out the errors and difficulties? > > > > It does also seem possible that the problems are initially caused by using > geographical (spherical) coordinates rather than projected coordinates. > Projection of the input points to say EPSG:3460, or for the broader > Pacific Basin EPSG:3832, may be helpful. See > https://www.asprs.org/wp-content/uploads/2012/05/10-2000-fiji.pdf for the > then (publication 2000) valid description of why EPSG only seems to record > Fiji with 1956 (international ellipsoid) and 1986 (WGS1972 ellipsoid). > > EPSG:4326 can be transformed to EPSG:3460 with 2m accuracy. Using then a > projected planar extent in the local grid, the problem of crossing 180 > degrees is removed. In addition, the interpolation will use metres not > degrees as the metric of the positions of the points and grid cells. The > planar representation should also remove plotting problems. > > Hope this helps, > > Roger > > > > >> Hoping to find solutions to my problems and learn from this. > >> > >> yours sincerely > >> sownalc > >> Contact: sownalch...@gmail.com > >> PH +679 2960779 > >> > >> [[alternative HTML version deleted]] > >> > >> _______________________________________________ > >> R-sig-Geo mailing list > >> R-sig-Geo@r-project.org > >> > https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-sig-geo&data=04%7C01%7CRoger.Bivand%40nhh.no%7C3d492fafcd7247d2090e08da04cde59b%7C33a15b2f849941998d56f20b5aa91af2%7C0%7C0%7C637827580063300234%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=BbbD%2BNIDVs82yx2JHiO3PTxUD%2BBUH%2FXdpirZCFGAmn0%3D&reserved=0 > > > > > > -- > Roger Bivand > Emeritus Professor > Department of Economics, Norwegian School of Economics, > Postboks 3490 Ytre Sandviken, 5045 Bergen, Norway. > e-mail: roger.biv...@nhh.no > https://orcid.org/0000-0003-2392-6140 > https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo