Re: NonLinearRegression Weights
- To: mathgroup at smc.vnet.net
- Subject: [mg73629] Re: NonLinearRegression Weights
- From: Lawrence Walker <lwalker701 at earthlink.net>
- Date: Fri, 23 Feb 2007 04:39:46 -0500 (EST)
- References: <erjoum$pp0$1@smc.vnet.net>
pershan at seas.harvard.edu wrote:
> The command I am using is:
> fitting[x_] = NonlinearFit[data, f[x], {x}, {
> {Background, {0, 1000}},
> {Amplitude, {10, 0}},
> {Wid, {10, 25}}}, Weights -> wt]
> where wt is a column vector that has precisely the same length as the
> data file.
Column vector? Did you use something like Weights ->{{1},{1},...}
instead of Weights->{1,1,...}?
> This command works perfectly if I use either Weights->Automatic or
> something like Weights -> (Sqrt[#] &)
> On the other hand, when the weights are from a list {....} I get the
> following error.
>
> NonlinearFit::bdwghts: Warning: Value of option Weights ->
> {{0.00322435}, \
> {0.00359912}, \[LeftSkeleton]8\[RightSkeleton], \[LeftSkeleton]31\
> \[RightSkeleton]} is not Automatic, a pure function mapping a
> response to a \
> non-negative numerical weight, or a non-negative numerical vector
> having the \
> same length as the data. Setting all weights to 1 (Weights ->
> Automatic).
The error you are getting leads me to believe that the value to the
Weights option is not a vector of numbers (VectorQ[#,NumericQ]&).