yes, but in `rutledge` I model y as `y = (M / ( 1 + exp(-(x-m)/s)) ) + B`, with x being 1:45. Isn't that the equivalent of what I fed Desmos with? Tx
On Wed, Mar 17, 2021 at 11:31 AM Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > > On 17/03/2021 5:41 a.m., Luigi Marongiu wrote: > > Hello, > > I have a dataset from a polymerase chain reaction. I am using the > > equation given by Rutledge > > (https://pubmed.ncbi.nlm.nih.gov/15601990/) but the profile I get in R > > does not match the data. I ran the same thing in Desmos and instead > > the profile is correct (attached). > > Why do I not get the same matching model as in Desmos? I believe the > > formula in R is the same as the one in Desmos, and I am using the same > > parameters. > > Is there a procedure to debug models? > > Thanks > > > > Here is the code: > > ``` > > high <- c(120.64, 66.14, 34.87, 27.11, 8.87, -5.8, 4.52, -7.16, -17.39, > > -14.29, -20.26, -14.99, -21.05, -20.64, -8.03, -21.56, -1.28, 15.01, > > 75.26, 191.76, 455.09, 985.96, 1825.59, 2908.08, 3993.18, 5059.94, > > 6071.93, 6986.32, 7796.01, 8502.25, 9111.46, 9638.01, 10077.19, > > 10452.02, 10751.81, 11017.49, 11240.37, 11427.47, 11570.07, > > 11684.96, > > 11781.77, 11863.35, 11927.44, 11980.81, 12021.88) > > plot(1:45, high, type = "l") > > rutledge <- function(p, x) { > > m = p$half_fluorescence > > s = p$slope > > M = p$max_fluorescence > > B = p$back_fluorescence > > y = (M / ( 1 + exp(-(x-m)/s)) ) + B > > return(y) > > } > > desmos <- rutledge(list(half_fluorescence = 27.1102, slope = 2.76798, > > max_fluorescence = 11839.8, back_fluorescence > > = -138.864) , high) > > > > points(1:45, desmos, type="l", col="blue") > > > In your calculation of desmos, you are using the Y variable for x in the > formula. Calculate it this way instead: > > desmos <- rutledge(list(half_fluorescence = 27.1102, slope = 2.76798, > max_fluorescence = 11839.8, back_fluorescence > = -138.864) , 1:45) > > Duncan Murdoch > -- Best regards, Luigi ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.