For creating a logarithmic graph you can right click on the axis and edit axis.This will prompt you the above window, where you can change the scale as you wish.There is an option to select logarithmic scale.
In related to your second question , it would be great if you could elaborate a little bit. What did you mean by automate creation of scatter plot? You want a script to create scatter plots automatically?
I'm afraid that I wasn't clear on either of my questions.
On questions #1, I understand how to change the axis to being a log, but I have to do this every time I create a chart. Is there a setting that would allow me to modify all charts so by default they used a log scale?
On question #2, Yes, effectively I want a script, or automated way, to create a series of scatterplots. I have about thirty of these I am doing and it'd tedious to manually create a new sheet, drop the measures and dimensions, and then reset the scale to log.
Currently, this is a manual process. Sounds like a good one for the Ideas section!
Would it be possible, once you have one chart setup the way you want, to use the "Duplicate Sheet" functionality (right click the view's tab) and then swap out the measures?
If they are in separate workbooks, you might consider using bookmarks to give you a starting place so you don't have to repeat every step.