:: Generate a prism model from a tesseroid model by
:: flattening the tesseroids (1 degree = 111.11 km).
:: This way the converted prisms can be used
:: with the prism* programs in Cartesian coordinates.

tess2prism --flatten < tess-model.txt > prism-model.txt

:: Generate a regular grid in Cartesian coordinates,
:: pipe the grid to the computation programs,
:: and dump the result on output.txt

tessgrd -r-3e06/3e06/-3e06/3e06 -b50/50 -z250e03 | ^
prismpot prism-model.txt | ^
prismgx prism-model.txt | ^
prismgy prism-model.txt | ^
prismgz prism-model.txt | ^
prismgxx prism-model.txt  | prismgxy prism-model.txt  | ^
prismgxz prism-model.txt  | prismgyy prism-model.txt  | ^
prismgyz prism-model.txt  | prismgzz prism-model.txt > output.txt