Q: I cannot see one of my layers as a line in the Plot Window. How can I see it?
A: Sometimes a layer is hidden by a higher velocity layer below or by a very high dip. You may have to adjust the model manually to make the layer visible (perhaps thickening the layer in question or making its velocity higher).
Q: I make some line fits and then press the Invert from Plot button, but the lines then move far away from where I put them. Why is this, and what can I do?
A: You positioned the lines in a manner somehow inconsistent with a model of constant velocity layers. Studying how the inversion changed the lines will frequently reveal the cause. Starting from the shallowest layers and working gradually down can often resolve this. Additionally, it is possible that the material under the profile has laterally varying velocities and/or non-planar interfaces.
Q: I have my lines and they seem OK, but when I press the Model from Plot button, I get an error that the velocities are in error because the apparent velocities decrease with depth. What is wrong?
A: You probably got the lines out of order. So, for instance, if you have 3 layers, the steepest (slowest) line must be labelled 1F (if forward, 1R if reversed), second line 2F, third 3F. Probably you have 3F before 2F.
Q: I saved my data or model and then could not reread it. What is wrong?
A: Add the .txt suffix to the filename should allow you to read the file. It is possible if you edited the file that you did not save the file in a plain text format (e.g., Apple's TextEdit tends to save things as rich text format (.rtf) files, which Refract cannot read). Try saving as "plain text" or using a true simple text editor (e.g., TextWrangler on the Mac).