Well, you were right. When I check with str() or summary(), the data frame appears as having a factor for that column. However, if I ask is.factor(C2), I get FALSE, and if I ask is.numeric(C2) I get TRUE. This seems strange. So I decided to reimport the dataframe, this time with NA as undefined values, and not ?. C2 was imported as a numeric variable, as checked with str() and is.numeric(). But I still get the indexes and not the values when I use C2 for any purpose, just as happened before. How can this be possible? All the other columns in the table behave properly. The only difference I see between this columns ans the others is that it contains NA values.
Thanks again, Francisco Torreira ---- Original message ---- >Date: Sun, 14 Aug 2005 10:11:15 +0100 >From: Patrick Burns <[EMAIL PROTECTED]> >Subject: Re: [R] Problem with numeric variable >To: [EMAIL PROTECTED] > >I think your problem is that you have a factor rather >than a numeric vector (even though you say you checked >with 'is.numeric'). Missing values should be represented >by 'NA' and not by '?' which is what makes me think you >have a factor. > >Patrick Burns >[EMAIL PROTECTED] >+44 (0)20 8525 0696 >http://www.burns-stat.com >(home of S Poetry and "A Guide for the Unwilling S User") > >[EMAIL PROTECTED] wrote: > >>Hello all, >> >>I posted a question some days ago without getting any answers, >>perhaps, as one of you kindly pointed out, because the >>question was not clearly stated. Let me reformulate it: >>In a frame, a column named C2 represents a numeric variable >>(checked with is.numeric(C2)). Some rows in the frame have an >>undefined value for C2, represented in the table by a ? sign. >>The remaining rows have numeric values with 2 decimals. For >>example, row 10 has 43.70 for C2, while row 1 has ?. The >>problem is that when I list C2 values (or when I try to plot >>them, etc), these values are not the ones that appeared in the >>table. Below are the first 3 lines of what I get when I list C2: >> >> >>>C2 >>> >>> >>[1] 43 47 96 62 87 55 1 98 121 1 1 1 67 1 112 1 93 44 >>[19] 85 569 52 110 126 95 92 60 36 383 373 298 274 406 208 175 >>293 306 >>[37] 305 172 134 115 94 84 104 99 64 271 269 310 268 359 443 >>248 204 345 >> >>These are not the correct values for C2, and I guess that they >>are just row numbers. How can I get the correct C2 values >>ready for analysis? Is this problem related to the fact that >>some rows have a ? value for C2? >> >>Thanks in advance, >>Francisco Torreira >>Francisco Torreira >>Spanish, Italian and Portuguese >>Univ. of Illinois at Urbana-Champaign >>707 South Mathews Aven. >>4031 FLB >>Urbana, IL, 61801 >> >>______________________________________________ >>R-help@stat.math.ethz.ch mailing list >>https://stat.ethz.ch/mailman/listinfo/r-help >>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >> >> >> >> >> > Francisco Torreira Spanish, Italian and Portuguese Univ. of Illinois at Urbana-Champaign 707 South Mathews Aven. 4031 FLB Urbana, IL, 61801 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html