Displaying 4 results from an estimated 4 matches for "heptot".
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2023 Nov 06
2
non-linear regression and root finding
...find pH values and thereby find the
lowest deviation vis a vis measured values. That works but requires many
triplets and is not satisfying. Hence I wonder if I could somehow have
non linear regression to find the 3 pK values. Below is HEPESFUNC which
delivers charge in the fluid for known pKs, HEPTOT and SID. Is it
possible to have root-finding in the formula with nls? (I know the
precision asked for is extreme but it has worked well in really many
applications).
All best wishes
Troels Ring, MD
Aalborg, Denmark
HEPESFUNC <-
? function(H,SID,HEPTOT,pK1,pK2,pK3) {
??? XX <- (H^3/(1...
2023 Nov 06
1
non-linear regression and root finding
? Mon, 6 Nov 2023 17:53:49 +0100
Troels Ring <tring at gvdnet.dk> ?????:
> Hence I wonder if I could somehow have non linear regression to find
> the 3 pK values. Below is HEPESFUNC which delivers charge in the
> fluid for known pKs, HEPTOT and SID. Is it possible to have
> root-finding in the formula with nls?
Sure. Just reformulate the problem in terms of a function that takes a
vector of predictors (your independent variable SID) and the desired
parameters (pK1, pK2, pK3) as separate arguments and then returns
predicted values...
2023 Nov 06
2
non-linear regression and root finding
...9:19 skrev Ivan Krylov:
> ? Mon, 6 Nov 2023 17:53:49 +0100
> Troels Ring <tring at gvdnet.dk> ?????:
>
>> Hence I wonder if I could somehow have non linear regression to find
>> the 3 pK values. Below is HEPESFUNC which delivers charge in the
>> fluid for known pKs, HEPTOT and SID. Is it possible to have
>> root-finding in the formula with nls?
> Sure. Just reformulate the problem in terms of a function that takes a
> vector of predictors (your independent variable SID) and the desired
> parameters (pK1, pK2, pK3) as separate arguments and then returns...
2023 Nov 06
1
non-linear regression and root finding
...>> ? Mon, 6 Nov 2023 17:53:49 +0100
>> Troels Ring <tring at gvdnet.dk> ?????:
>>
>>> Hence I wonder if I could somehow have non linear regression to find
>>> the 3 pK values. Below is HEPESFUNC which delivers charge in the
>>> fluid for known pKs, HEPTOT and SID. Is it possible to have
>>> root-finding in the formula with nls?
>> Sure. Just reformulate the problem in terms of a function that takes a
>> vector of predictors (your independent variable SID) and the desired
>> parameters (pK1, pK2, pK3) as separate arguments...