[R] Understanding cenros Error

[MacQueen, Don]

An my "easy" but not very useful answer is that this particular subset
probably violates some assumption of the cenros() model. I myself would
start with simple inspections of the data, such as

  with( subset(chem, param=='Ag'),  table(ceneq1) )
  with( subset(chem, param=='Ag'), qqnorm(quant) )
  with( subset(chem, param=='Ag'), range(quant) )


in the hopes that something pops out.

Do you have any zeros in quant?  (see ?cenros)

-Don

-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062





On 7/10/12 12:54 PM, "Rich Shepard" <rshepard at appl-ecosys.com> wrote:

>   Before reading water chemistry into a data frame I removed all missing
>data. Yet when I try to run cenros() to summarize a specific chemical I
>get
>an error that I do not understand:
>
>with( subset(chem, param=='Ag'),  cenros(quant,ceneq1) )
>Error in lm.fit(x, y, offset = offset, singular.ok = singular.ok, ...) :
>   NA/NaN/Inf in 'y'
>
>   I would like to learn what I did incorrectly so I can avoid these
>errors
>in the future.
>
>   The data frame structure is
>
>str(chem)
>'data.frame':	120309 obs. of  8 variables:
>  $ site    : Factor w/ 65 levels ";Influent","D-1",..: 2 2 2 2 2 2 ...
>  $ sampdate: Date, format: "2007-12-12" "2007-12-12" ...
>  $ preeq0  : logi  TRUE TRUE TRUE TRUE TRUE TRUE ...
>  $ param   : Factor w/ 37 levels "Ag","Al","Alk_tot",..: 1 2 8 17 3 9 ...
>  $ quant   : num  0 0.106 1 231 231 0.011 0 0.002 0 100 ...
>  $ ceneq1  : logi  FALSE FALSE TRUE FALSE FALSE FALSE ...
>  $ floor   : num  0 0.106 0 231 231 0.011 0 0 0 100 ...
>  $ ceiling : Factor w/ 3909 levels "0.000","0.000)",..: 1 116 841 1771
>...
>
>   I ran dput() on the data frame but cannot make sense of the output (a
>5.5M
>ASCII text file).
>
>   Pointers appreciated.
>
>Rich
>
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