I use the last versions of R -4.0.3- and sf -0.9.6- (thus relying on PROJ version 6.3.1).
I want to transform a layer from one system of coordinates (EPSG:27572) to another (EPSG:2154). This can be done with (accurate) or without (less accurate) using a transformation grid file. Once I have copied the appropriate transformation grid file (ntf_r93.gsb for PROJ 6) in the proj directory of sf (located at "C:\Program Files\R\R-4.0.3\library\sf\proj" on my PC), st_transform automatically use it and gives the most accurate results:
My question is:
- how to get rid of the transformation grid, coming back to the non-gridded transformation, without removing the file in the proj directory?
- Is there any sf command, or any parameter in st_transform to do this simply?
- Perhaps using the pipeline parameter?