flst与fitem命令是这么用的

k,94,75.69947,44.09817,-40
k,95,50.9349,44.01963,-40
k,96,37.83799,45.04814,-40
k,97,15.1304,48.29342,-40
k,98,-3.62213,52.15532,-40
FLST,3,5,3
FITEM,3,94
FITEM,3,95
FITEM,3,96
FITEM,3,97
FITEM,3,98
bspline,,p51x