Change CRS +proj=longlat +datum=WGS84 +pm=-160 +no_defs +ellps=WGS84 +towgs84=0,0,0

1
votes

I have downloaded a SpatialLinesDataFrame from http://www.esapubs.org/archive/ecol/E094/150/#data with the following CRS +proj=longlat +datum=WGS84 +pm=-160 +no_defs +ellps=WGS84 +towgs84=0,0,0.

I need to change this projection to regular longlat and make a diversity map out of this dataset. The problem is that a regular reprojection does not work because the coordinates will go over 180 degrees east. Could anyone give some suggestion how to reproject this dataset and to extract raster layers at 5 arcminutes spatial resolution. This will allow me to stack the raster files and extract biodiversity values.

Any help is appreciated, Niels

1
projectionraster
have you access to the paper and an idea of the expected geographical range? – Paulo E. Cardoso
besides that, this may provide some insights. – Paulo E. Cardoso
Hi Paulo, the extent is: extent(IPcoralrangeboundaries) class : Extent xmin : -177.4437 xmax : 85.15434 ymin : -40.68847 ymax : 40.12325 Now 160 + 85 goes over 180 degrees east which is correct, because these are the French Polynesian coral reefs. But how to get the Lines over that border? The RDATA set is readily available from the above link - Niels – Niels Raes
My question was about the expected range. I found these values too with raster::extent. I'm concerned about their validity. It was correctly assigned? Did you try to represent the data in a GIS? – Paulo E. Cardoso
This seems to work IPcoralrangeboundaries.shift <- elide(IPcoralrangeboundaries, shift=c(200, 0)) – Niels Raes

1 Answers

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I closed the lines to polygons and rasterized those to get gridded data. Those were written in a dataframe and I corrected the longitude values in the dataframe. This allowed me to get 'normal' latlong coordinates for the gridded data. That works for now. Niels