Re: [R] "Invalid object" error in boxplot

From: Erik Iverson <iverson_at_biostat.wisc.edu>
Date: Tue, 01 Jul 2008 12:35:54 -0500

The advice is to store numeric data as numeric, and not factors. Try str(yourdata) and you'll probably see that Diatoms is stored as a 'factor'. Are those commas used as decimal points? read.table can deal with that if so. If not, you do not need them, and should convert those fields to numeric after getting rid of the ',' characters.

mm745_at_st-andrews.ac.uk wrote:
> Hi,
>
> I'm trying to make a boxplot with the data at the end of the message, and when I
> try to execute the command
>

>> boxplot(Diatoms) (or for any other field instead of "Diatoms")

>
> I get the following error message:
>
> Error in oldClass(stats) <- cl : adding class "factor" to an invalid object
>
> Any advice would be much appreciated.
>
> Thanks a lot,
>
> Miriam
>
>
>
> Date Depth Diatoms Bacteria V1 V2 V3
> 1 15/02/2000 0 17 700,000 14,067,895 380,000 69,000
> 2 15/02/2000 2 17 316,680 9,311,160 250,000 26,000
> 3 15/02/2000 10 20 313,010 8,422,355 460,000 30,000
> 4 15/02/2000 20 21 374,535 9,259,900 280,000 33,000
> 5 22/02/2000 0 21 370,000 16,952,360 320,000 72,000
> 6 22/02/2000 2 21 462,480 10,526,390 360,000 64,000
> 7 22/02/2000 10 39 374,860 8,378,655 290,000 49,000
> 8 22/02/2000 20 140 381,900 9,468,550 390,000 73,000
> 9 29/02/2000 0 240 200,000 5,783,980 440,000 61,000
> 10 29/02/2000 2 240 224,125 8,077,105 600,000 89,000
> 11 29/02/2000 10 110 190,810 8,154,005 600,000 61,000
> 12 29/02/2000 20 460 177,050 8,333,120 600,000 69,000
> 13 08/03/2000 0 1,800 270,000 5,277,265 200,000 34,000
> 14 08/03/2000 2 1,800 403,380 9,237,105 490,000 80,000
> 15 08/03/2000 10 1,400 372,530 10,624,735 480,000 57,000
> 16 08/03/2000 20 3,100 261,215 6,228,160 340,000 37,000
> 17 14/03/2000 0 4,900 750,000 16,258,720 440,000 80,000
> 18 14/03/2000 2 4,900 633,895 10,952,305 380,000 54,000
> 19 14/03/2000 10 4,100 583,367 10,383,383 310,000 53,000
> 20 14/03/2000 20 8,200 653,945 10,148,210 380,000 48,000
> 21 21/03/2000 0 850 570,000 11,000,000 180,000 170,000
> 22 21/03/2000 2 850 520,000 27,000,000 130,000 190,000
> 23 21/03/2000 10 1,800 540,000 21,000,000 250,000 140,000
> 24 21/03/2000 20 1,800 470,000 10,000,000 110,000 70,000
> 25 27/03/2000 0 1,300 640,000 13,000,000 170,000 90,000
> 26 27/03/2000 2 1,300 770,000 17,000,000 230,000 120,000
> 27 27/03/2000 10 520 720,000 15,000,000 120,000 170,000
> 28 27/03/2000 20 130 620,000 12,000,000 98,000 74,000
> 29 04/04/2000 0 2,003 940,000 29,582,000 190,000 46,000
> 30 04/04/2000 2 2,003 952,400 27,186,525 210,000 67,000
> 31 04/04/2000 10 1,671 503,300 11,140,225 85,000 24,000
> 32 04/04/2000 20 863 682,550 14,605,825 140,000 32,000
> 33 07/04/2000 0 1,653 840,000 15,862,125 370,000 95,000
> 34 07/04/2000 2 1,653 819,350 13,099,600 280,000 67,000
> 35 07/04/2000 10 1,520 769,825 13,395,825 240,000 57,000
> 36 07/04/2000 20 422 784,700 10,910,700 170,000 28,000
> 37 12/04/2000 0 7,671 640,000 9,851,750 470,000 100,000
> 38 12/04/2000 2 7,671 600,625 9,339,400 490,000 170,000
> 39 12/04/2000 10 5,865 585,650 8,439,300 450,000 180,000
> 40 12/04/2000 20 1,276 595,225 7,297,150 360,000 92,000
> 41 14/04/2000 0 10,479 730,000 12,406,650 540,000 140,000
> 42 14/04/2000 2 10,479 700,000 10,406,650 490,000 110,000
> 43 14/04/2000 10 6,576 682,500 9,869,050 470,000 100,000
> 44 14/04/2000 20 3,307 739,075 8,875,250 420,000 180,000
> 45 16/04/2000 0 1,636 890,000 9,653,050 290,000 120,000
> 46 16/04/2000 2 1,636 885,725 9,934,300 300,000 97,000
> 47 16/04/2000 10 2,986 973,750 10,270,975 310,000 190,000
> 48 16/04/2000 20 1,222 629,250 6,792,500 210,000 90,000
> 49 19/04/2000 0 656 730,000 12,751,350 510,000 150,000
> 50 19/04/2000 2 656 831,575 13,673,700 400,000 120,000
> 51 19/04/2000 10 480 723,925 11,230,150 420,000 100,000
> 52 19/04/2000 20 872 671,975 9,858,900 330,000 97,000
> 53 27/04/2000 0 180 1,000,000 15,346,525 370,000 85,000
> 54 27/04/2000 2 180 926,800 22,825,400 670,000 93,000
> 55 27/04/2000 10 7 880,925 15,121,675 490,000 86,000
> 56 27/04/2000 20 64 723,100 10,638,400 230,000 21,000
>
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Tue 01 Jul 2008 - 18:00:03 GMT

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