I don't understand your quesiton.
If you have a set of data points and graph them, then it seems reasonable to me that one could put a case forward that the data set is a small sample of a: e.g. a sine wave, hyperbola, tan function, etc. Can you tell what part of the curve and what curve function it really is, especially if you are relying on averaged data with some margin of error?
Humphries equation has an upper bound based on the mass of the planet, and variable that takes on the values of 0, 1/4, 1/2, 3/4, and 1 based on potential molecule orientations.
It worse than that, One of Humphries assumptions is a young earth (represented as Ã¢â‚¬ËœtÃ¢â‚¬â„¢) as an input to his equations, that IMO is circular since one is trying to predict the age of the earth in the first place.
If you think that "predicts at once every possible observed field "then you are mathematically challanged, and I can't help you.
Instead of the petty complaints, why don't you show us where the dynamo theory works better than Humphreys' model at predicting the field strengths of other planets?
Well since you are lettered mathematically, could you please critique the talk origins reply, where the equations are dissected (The lack of predictive quality is also explained in the link) and comment upon the false (if any) reasoning.
IÃ¢â‚¬â„¢m sure IÃ¢â‚¬â„¢m not that mathematically challenged, that I could not follow a simplified explanation.