how to specify points outside a polygon?

For example, in the below code, I can specify the points inside the polygon. How about outside the polygon? How do I specify that?

IN = inpolygon(lon, lat, x0, y0);

lon  = lon(IN);
lat  = lat(IN);
ph1  = ph1(IN);

Answer 1

[Walter Roberson]

IN = inpolygon(lon, lat, x0, y0);

lon  = lon(~IN);
lat  = lat(~IN);
ph1  = ph1(~IN);

Answer 2

[Leon]

Many thanks for the help!