[R] How to coerce a parameter in nls?

[Jianling Fan]

no, I am doing a regression with 6 group data with 2 shared parameters
and 1 different parameter for each group data. the parameter I want to
coerce is for one group. I don't know how to do it. Any suggestion?

Thanks!

On 19 September 2015 at 13:33, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:
> Why not rewrite the function so that value is not a parameter?
> ---------------------------------------------------------------------------
> Jeff Newmiller                        The     .....       .....  Go Live...
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> Sent from my phone. Please excuse my brevity.
>
> On September 18, 2015 9:54:54 PM PDT, Jianling Fan <fanjianling at gmail.com> wrote:
>>Hello, everyone,
>>
>>I am using a nls regression with 6 groups data. I am trying to coerce
>>a parameter to 1 by using a upper and lower statement. but I always
>>get an error like below:
>>
>>Error in ifelse(internalPars < upper, 1, -1) :
>>  (list) object cannot be coerced to type 'double'
>>
>>does anyone know how to fix it?
>>
>>thanks in advance!
>>
>>My code is below:
>>
>>
>>
>>> dproot
>>   depth       den ref
>>1     20 0.5730000   1
>>2     40 0.7800000   1
>>3     60 0.9470000   1
>>4     80 0.9900000   1
>>5    100 1.0000000   1
>>6     10 0.6000000   2
>>7     20 0.8200000   2
>>8     30 0.9300000   2
>>9     40 1.0000000   2
>>10    20 0.4800000   3
>>11    40 0.7340000   3
>>12    60 0.9610000   3
>>13    80 0.9980000   3
>>14   100 1.0000000   3
>>15    20 3.2083491   4
>>16    40 4.9683383   4
>>17    60 6.2381133   4
>>18    80 6.5322348   4
>>19   100 6.5780660   4
>>20   120 6.6032064   4
>>21    20 0.6140000   5
>>22    40 0.8270000   5
>>23    60 0.9500000   5
>>24    80 0.9950000   5
>>25   100 1.0000000   5
>>26    20 0.4345774   6
>>27    40 0.6654726   6
>>28    60 0.8480684   6
>>29    80 0.9268951   6
>>30   100 0.9723207   6
>>31   120 0.9939966   6
>>32   140 0.9992400   6
>>
>>> fitdp<-nls(den~Rm[ref]/(1+(depth/d50)^c),data=dproot,
>>+ start = list(Rm=c(1.01, 1.01, 1.01, 6.65,1.01,1), d50=20, c=-1))
>>> summary(fitdp)
>>
>>Formula: den ~ Rm[ref]/(1 + (depth/d50)^c)
>>
>>Parameters:
>>    Estimate Std. Error t value Pr(>|t|)
>>Rm1  1.12560    0.07156   15.73 3.84e-14 ***
>>Rm2  1.57643    0.11722   13.45 1.14e-12 ***
>>Rm3  1.10697    0.07130   15.53 5.11e-14 ***
>>Rm4  7.23925    0.20788   34.83  < 2e-16 ***
>>Rm5  1.14516    0.07184   15.94 2.87e-14 ***
>>Rm6  1.03658    0.05664   18.30 1.33e-15 ***
>>d50 22.69426    1.03855   21.85  < 2e-16 ***
>>c   -1.59796    0.15589  -10.25 3.02e-10 ***
>>---
>>Signif. codes:  0 ?**?0.001 ?*?0.01 ??0.05 ??0.1 ??1
>>
>>Residual standard error: 0.1094 on 24 degrees of freedom
>>
>>Number of iterations to convergence: 8
>>Achieved convergence tolerance: 9.374e-06
>>
>>> fitdp1<-nls(den~Rm[ref]/(1+(depth/d50)^c),data=dproot,
>>algorithm="port",
>>+ start = list(Rm=c(1.01, 1.01, 1.01, 6.65, 1.01, 1), d50=20, c=-1),
>>+ lower = list(Rm=c(1.01, 1.01, 1.01, 6.65, 1.01, 1), d50=20, c=-1),
>>+ upper = list(Rm=c(2.1, 2.2, 2.12, 12.5, 2.3, 1), d50=50, c=1))
>>
>>Error in ifelse(internalPars < upper, 1, -1) :
>>  (list) object cannot be coerced to type 'double'
>>
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>



-- 
Jianling Fan
樊建凌