aproom.psu.edu/dcw/. An example is provided here. The first line contains the name of the file, the second line contains the name of an individual polygon and if it is prefixed with ! it means it is a negative polygon to be subtracted from the resultant extraction polygon.
australia_v 1 0.1446763E+03 -0.3825659E+02 0.1446693E+03 -0.3826255E+02 0.1446627E+03 -0.3825661E+02 0.1446763E+03 -0.3824465E+02 0.1446813E+03 -0.3824343E+02 0.1446824E+03 -0.3824484E+02 0.1446826E+03 -0.3825356E+02 0.1446876E+03 -0.3825210E+02 0.1446919E+03 -0.3824719E+02 0.1447006E+03 -0.3824723E+02 0.1447042E+03 -0.3825078E+02 0.1446758E+03 -0.3826229E+02 0.1446693E+03 -0.3826255E+02 END !2 0.1422483E+03 -0.3839481E+02 0.1422436E+03 -0.3839315E+02 0.1422496E+03 -0.3839070E+02 0.1422543E+03 -0.3839025E+02 0.1422574E+03 -0.3839155E+02 0.1422467E+03 -0.3840065E+02 0.1422433E+03 -0.3840048E+02 0.1422420E+03 -0.3839857E+02 0.1422436E+03 -0.3839315E+02 END END
@author Brett Henderson