[ferret_users] vectors thicker?

[James Booth <jbooth@xxxxxxxxxxxxxxxxxxxx>]

I am using an older version of ferret: FERRET v5.51

I am looking to make the vector lines thicker, however,
when I use

vec/pen=1/thickness=2 myu, myv

I  find that the NaN values get represented by asterisks instead of
small dots, as they are for thickness=1.

Is there a work-around for this? 
Are my NaN values not really NaN values? (I set them to 1e-34)

Attached is afigure with the astericks.

*_*_*_*_*_*
Jimmy Booth

Attachment: vec_thick2.jpg
Description: JPEG image