Hi Chris, thanks for your reply. The dx file was the result of an
Export("dx text"). I deleted data to make posting smaller.>Let's start over: let's say you have arbitrary data, like scalar floats >in the range 1.0-100.0. You want to invalidate some of the positions >based on the data. Let's say you don't like values 1.0-10.0. Run the >field into: Compute(a<=10.0 ? byte(1) : byte(0)) Take the output of >the Compute (a field whose "data" is now all byte 1 or 0) into Replace >"source" and the original field (prior to Compute) into Replace >"destination", then set source component "data" and destination component >"invalid positions". You're done. You have a one to one correspondence of >invalids to positions, and data to positions. Your original data is still >in the "data" component, inherited via the destination field. The invalid >positions component has been added to the result field (a very useful use >for Replace: it also can do Insert). Does that help? Yes. I thought I would need a second Replace to put data back in (wasn't thinking straight). So I now have a field with invalid positions, checked this by passing through an AutoColor and Image, looks fine. But when I pass this through a Band module I get the dreaded Error: Band: Invalid data: dependent invalid data component must be scalar bytes. Cheers, Simon. // Simon Spagnol, [EMAIL PROTECTED] // Australian Institute of Marine Science // PMB No 3, Townsville QLD 4810, Australia // ph: +61-7-47534444, fax: +61-7-47725852
