[R] NLS plinear question

Hi All. I've run into a problem with the plinear algorithm in nls that is confusing me. Assume the following reaction time data over 15 trials for a single unit. Trials are coded from 0-14 so that the intercept represents reaction time in the first trial. trl RT 01132.0 1 630.5

Re: [R] NLS plinear question

recall that 0 ^{-.2} = 1/0^{.2}, and that dividing by 0 gives Inf. so when 0 is in trl, part of your model for RT is Inf: trl - 0:14 p - -.2 cbind(1,trl, trl^p) trl [1,] 1 0 Inf [2,] 1 1 1.000 [3,] 1 2 0.8705506 [4,] 1 3 0.8027416 [5,] 1 4 0.7578583 [6,] 1 5

Re: [R] NLS plinear question

0^(-0.2) = Inf, so you started with an infinite prediction for your first point and hence an infinite sum of squares. On Tue, 6 May 2008, Rick DeShon wrote: Hi All. I've run into a problem with the plinear algorithm in nls that is confusing me. Assume the following reaction time data over