Accepted answer: no
In the initial game docs, it was stated that the fallout pattern from XMP attacks was linear, yet the accepted best attack pattern was to blow them right on top of a resonator before moving to the next one.
More recently, a number of people have done the math and decided it would be more efficient, given a linear fallout, to just blow from the center of the portal. This advice has turned up in my local area and it looks like it's surfaced on reddit and elsewhere.
It seems there is circumstantial and experiential evidence that the fallout is actually some sort of quadratic equation, and that this might be a recent change. The current field guide doesn't seem to give any indication of how this works.
Is there any confirmed (either from Niantic or documented experimentation) evidence for a quadratic fallout formula? Am I correct in understanding that an optimum attack sequence (all other factors being equal) would be 'blow from the center' for a linear model if the answer is no and a positional 1-3-5-7 or similar alternating 'stand on the resonator' technique if the answer is yes?