Salutations,
Long story short: I need to create an SPDF to superimpose on a Google map.
I have .shp file which has a long list of locations listed in (what I guess
must be) UTM. I need to transform these into lon, lat. My use of
spTransform, however, keeps giving me the wrong results. For what it's
worth, it only seems to be messing up the latitude.
My final line of code looks like this:
pointsTransformed <- spTransform(pointsutm, CRS("+proj=longlat +datum=WGS84
+zone=36S"))
The line before looks like:
pointsutm <- SpatialPoints(cbind(pointsmapspatial$Point_Y,
pointsmapspatial$Point_X), proj4string = CRS("+proj=utm +zone=36S
+ellps=GRS80")
Can you see what I did wrong?
spTransform
2 messages · Abed W. Ayyad, Thierry Onkelinx
2 days later
Dear Abed,
This is rather a question for r-gis-geo
Try two things:
1) simplify the CRS of the transformation
pointsTransformed <- spTransform(pointsutm, CRS("+proj=longlat"))
2) check the projection of the original data
Best regards,
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and
Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium
To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to say
what the experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey
2017-05-12 17:51 GMT+02:00 Abed W. Ayyad <abdulhadi.ayyad at uclmail.net>:
Salutations,
Long story short: I need to create an SPDF to superimpose on a Google map.
I have .shp file which has a long list of locations listed in (what I guess
must be) UTM. I need to transform these into lon, lat. My use of
spTransform, however, keeps giving me the wrong results. For what it's
worth, it only seems to be messing up the latitude.
My final line of code looks like this:
pointsTransformed <- spTransform(pointsutm, CRS("+proj=longlat +datum=WGS84
+zone=36S"))
The line before looks like:
pointsutm <- SpatialPoints(cbind(pointsmapspatial$Point_Y,
pointsmapspatial$Point_X), proj4string = CRS("+proj=utm +zone=36S
+ellps=GRS80")
Can you see what I did wrong?
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