Hi, Does your data have missing values? I am not sure it would change anything, but perhaps try adding:
cor(test2, method = "spearman", use = "pairwise.complete.obs") or something of the like. I am not sure what R does by default. My reasoning stems from this particular passage in the documentation: If ‘use’ is ‘"everything"’, ‘NA’s will propagate conceptually, i.e., a resulting value will be ‘NA’ whenever one of its contributing observations is ‘NA’. I do not think the names should make a difference (unless you're talking about human error). Best regards, Josh On Wed, Sep 8, 2010 at 12:35 PM, Stephane Vaucher <vauch...@iro.umontreal.ca> wrote: > Hi everyone, > > I'm observing what I believe is weird behaviour when attempting to do > something very simple. I want a correlation matrix, but my matrix seems to > contain correlation values that are not found when executed on pairs: > >> test2$P2 > > [1] 2 2 4 4 1 3 2 4 3 3 2 3 4 1 2 2 4 3 4 1 2 3 2 1 3 >> >> test2$HP_tot > > [1] 10 10 10 10 10 10 10 10 136 136 136 136 136 136 136 136 136 136 > 15 > [20] 15 15 15 15 15 15 c=cor(test2$P3,test2$HP_tot,method='spearman') >> >> c > > [1] -0.2182876 >> >> c=cor(test2,method='spearman') > > Warning message: > In cor(test2, method = "spearman") : the standard deviation is zero >> >> write(c,file='out.csv') > > from my spreadsheet > -0.25028783918741 > > Most cells are correct, but not that one. > > If this is expected behaviour, I apologise for bothering you, I read the > documentation, but I do not know if the calculation of matrices and pairs is > done using the same function (eg, with respect to equal value observations). > > If this is not a desired behaviour, I noticed that it only occurs with a > relatively large matrix (I couldn't reproduce on a simple 2 column data > set). There might be a naming error. > >> names(test2) > > [1] "ID" "NOMBRE" "MAIL" > [4] "Age" "SEXO" "Studies" > [7] "Hours_Internet" "Vision.Disabilities" "Other.disabilities" > [10] "Technology_Knowledge" "Start_Time" "End_Time" > [13] "Duration" "P1" "P1Book" > [16] "P1DVD" "P2" "P3" > [19] "P4" "P5" "P6" > [22] "P8" "P9" "P10" > [25] "P11" "P12" "P7" > [28] "SITE" "Errors" "warnings" > [31] "Manual" "Total" "H_tot" > [34] "HP1.1" "HP1.2" "HP1.3" > [37] "HP1.4" "HP_tot" "HO1.1" > [40] "HO1.2" "HO1.3" "HO1.4" > [43] "HO_tot" "HU1.1" "HU1.2" > [46] "HU1.3" "HU_tot" "HR" > [49] "L_tot" "LP1.1" "LP1.2" > [52] "LP1.3" "LP1.4" "LP_tot" > [55] "LO1.1" "LO1.2" "LO1.3" > [58] "LO1.4" "LO_tot" "LU1.1" > [61] "LU1.2" "LU1.3" "LU_tot" > [64] "LR_tot" "SP_tot" "SP1.1" > [67] "SP1.2" "SP1.3" "SP1.4" > [70] "SP_tot.1" "SO1.1" "SO1.2" > [73] "SO1.3" "SO1.4" "SO_tot" > [76] "SU1.1" "SU1.2" "SU1.3" > [79] "SU_tot" "SR" > > Thank you in advance, > Stephane Vaucher > > ______________________________________________ > R-help@r-project.org mailing list > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ R-help@r-project.org mailing list 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.