setprecision - et precision for decimal place of a stream
ostream int setprecision -> ostream
cerr 3 setprecision 3.12345678901 pprint endl -> 3.123
cerr 9 setprecision 3.12345678901 pprint endl -> 3.123456789
docu by Sirko Straube
/builddir/build/BUILD/nest-simulator-3.3/nest-simulator-3.3/sli/sli_io.cc