## August 8th, 2007

### Time Considered As A Helix of Probability Slopes

I was standing in the shower this morning thinking about the questions I was going to ask a colleague about how he wanted some data interpolated, and I suddenly had the realization that the way we had been going about it before was all wrong. Well, maybe not wrong, per se, but distinctly suboptimal.

Time, you see, is a helix. At least if you care about things relating to the seasonal cycle. So the right way to do these things is to interpolate from decades down to years along the surface of the cylinder, and then to unwind time back into a straight line and interpolate from seasons or months down to weeks or days once you have something for each year. Or, to put it another way, if you have a matrix with years along one dimension and months along the other, I was interpolating them in the wrong order (it needs to be years and *then* months) and pasting the results together, which makes for nasty jumps, rather than getting a smooth curve by doing it the other way around.