[R] Excel Trend Function

[paulandpen]

Hi Felipe,

Daniel mentions imputation is a disputed practice.  There are 
recommendations and rules of thumb for its use.  I am not sure that 
imputation is disputed.  I would be interested to see some links to articles 
recommending against its use.

Paul


----- Original Message ----- 
From: "Felipe Carrillo" <mazatlanmexico at yahoo.com>
To: <r-help at stat.math.ethz.ch>
Sent: Sunday, July 13, 2008 5:46 AM
Subject: [R] Excel Trend Function


> Hi:
> I have a dataset and need to interpolate for missing days. In Excel I 
> either average from sampled days from above and below the missing days or 
> use the TREND function to make up for the missing values. I have been 
> reading about na.approx, is this function similar to the TREND function? 
> Which is the best recommendable way to make up for missing data?
> Here's my dataset: weeks 17,18,26 and 46 have 0 daysSamp.
>
> Year Week daysSamp     Lower TotalPD Upper varTotalPD
> 2006 47 6 126988 188259 249530 1045878675
> 2006 48 7 189155 253350 317545 1148102355
> 2006 49 7 103300 132741 162182 241480186
> 2006 50 6 11801 252576 493352 16151006813
> 2006 51 7 2348 3671 4994 487926
> 2006 52 5 2606 29901 57196 215454181
> 2006 2 7 2968 4513 6058 664723
> 2006 3 7 1128 1889 2650 161231
> 2006 4 7 479 963 1447 65196
> 2006 5 7 2819 4413 6007 708094
> 2006 6 6 -1009 3128 7264 4766743
> 2006 7 7 -5239 10769 26777 71387835
> 2006 8 7 150 503 856 34685
> 2006 9 7 1858 2989 4120 356562
> 2006 10 7 193 494 795 25281
> 2006 11 7 125 346 567 13627
> 2006 12 7 432 767 1102 31189
> 2006 13 7 1229 1867 2505 113569
> 2006 14 7 813 1339 1865 77140
> 2006 15 4 -66 124 315 10105
> 2006 16 7 152 903 1654 157242
> 2006 17 0
> 2006 18 0
> 2006 19 5 0 0 0 0
> 2006 20 4 0 0 0 0
> 2006 21 5 0 0 0 0
> 2006 22 6 0 0 0 0
> 2006 23 7 -65 285 635 34112
> 2006 24 6 0 0 0 0
> 2006 25 7 0 0 0 0
> 2006 26 0
> 2006 27 4 228 931 1634 137726
> 2006 28 4 801 2231 3662 569977
> 2006 29 4 4544 9242 13939 6147522
> 2006 30 5 15798 28465 41131 44697915
> 2006 31 5 25398 41049 56701 68245523
> 2006 32 5 48197 82216 116235 322416917
> 2006 33 5 142980 230411 317841 2129630128
> 2006 34 5 227141 360468 493794 4952314336
> 2006 35 5 467244 756325 1045405 23281569629
> 2006 36 5 281049 463331 645614 9256900449
> 2006 37 2 227636 620330 1013023 42961663047
> 2006 38 3 478990 983472 1487954 70903343603
> 2006 39 7 539690 846522 1153354 26228718974
> 2006 40 7 320959 457866 594773 5221891252
> 2006 41 7 427561 582452 737343 6683813344
> 2006 42 7 271788 351103 430418 1752614293
> 2006 43 7 165019 208853 252687 535301133
> 2006 44 7 91514 117390 143266 186537178
> 2006 45 7 59061 79187 99313 112842787
> 2006 46 0
>
> Felipe D. Carrillo
> Supervisory Fishery Biologist
> Department of the Interior
> US Fish & Wildlife Service
>  California, USA
>
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