Dear All, Sorry to bother you again. As my previous mail was messy to understand, please find it again to give me a solution. I'd like to do a partial correaltion test ['pcor.test ()' or 'parcor()'] between Irid.area and Casa.PC1 variables controlling the influence of SL (co-variate) according to categorical group factors (Quantity or Quality group).
Can anyone give me any example or source of package that will be appreciated. I already tried with "ggm" (doesn't work in R now), "ppcor", but failed to modify or adjust with my data to anlyse as I want. My effort: > data1 Quantity Quality SL Irid.area Casa.PC1 1 High Low 16.38 10.31 1.71173956 2 High High 15.95 16.52 0.01338354 3 High High 15.69 12.74 2.22849088 4 High Low 14.76 9.80 1.55497583 5 High Low 14.63 12.95 1.82376797 6 High High 14.32 14.21 3.15205984 7 High High 14.95 12.57 2.06926504 8 High Low 15.37 13.55 1.88602742 9 High Low 14.73 14.18 1.12744060 10 High High 16.08 15.98 1.43556331 11 Low Low 13.95 16.05 -1.44961267 12 Low Low 14.03 12.58 -1.68596884 13 Low High 14.82 13.57 -0.09742642 14 Low High 14.32 12.16 -1.40351201 15 Low Low 14.33 7.66 -1.33665471 16 Low Low 15.01 10.15 -1.25701927 17 Low High 14.01 9.79 -0.71540450 18 Low Low 14.25 17.38 -1.29695402 19 Low High 14.55 16.11 -0.61689594 20 Low High 13.98 11.49 -0.65401736 > ### Correlation test according to group> library("MASS")> with(data1, > cor.test(~ Irid.area + Casa.PC1, subset=(Quantity=="High")))# gives cor, > df+2, p-values Pearson's product-moment correlation data: Irid.area and Casa.PC1 t = -1.0507, df = 8, p-value = 0.3241 alternative hypothesis: true correlation is not equal to 0 95 percent confidence interval: -0.8020154 0.3604104 sample estimates: cor -0.3482398 > with(data1, cor.test(~ Irid.area + Casa.PC1, subset=(Quantity=="Low")))# > gives cor, df+2, p-values Pearson's product-moment correlation data: Irid.area and Casa.PC1 t = 0.1209, df = 8, p-value = 0.9068 alternative hypothesis: true correlation is not equal to 0 95 percent confidence interval: -0.6031431 0.6547228 sample estimates: cor 0.04269795 > ### ppcor tests:> y.data <- data.frame(+ v1=data1$Irid.area,+ > v2=data1$Casa.PC1,+ f1=data1$Quantity,+ f2=data1$Quality)> > library(ppcor)> pcor(y.data)Error in pcor(y.data) : 'x' must be numeric ## I > also tried it with numeric values, but didn't give me the results same as > JMP> # partial correlation between "v1" and "v2" given "f1" and "f2"> > pcor.test(y.data$v1,y.data$v2,y.data[,c("f1","f2")])Error: is.numeric(y) || > is.logical(y) is not TRUE??? Then I tried with > #####pcor with ggm#####> library(ggm)# suggested by Andy Field et al. on > their book "Discovering statistics using R".Loading required package: > graphError: package graph could not be loaded> examData2<- data1[, > c("Irid.area", "Casa.PC1", "SL")]> maleExam<-subset(data1, Quantity == > "High", select= c("Irid.area", "Casa.PC1"))> femaleExam<-subset(data1, > Quantity == "Low", select= c("Irid.area", "Casa.PC1"))> cor(maleExam) > Irid.area Casa.PC1 Irid.area 1.0000000 -0.3482398 Casa.PC1 -0.3482398 1.0000000> cor(femaleExam) Irid.area Casa.PC1 Irid.area 1.00000000 0.04269795 Casa.PC1 0.04269795 1.00000000> # partial correlation between two var.> pcor.test(examData2$Irid.area, examData2$Casa.PC1, examData2$SL..COVARIATE.,Quantity == "High")Error in pcor.test(examData2$Irid.area, examData2$Casa.PC1, examData2$SL..COVARIATE., : 'use' should be either "rec" or "mat"!In addition: Warning messages:1: In if (use == "mat") { : the condition has length > 1 and only the first element will be used2: In if (use == "rec") { : the condition has length > 1 and only the first element will be used So, again can anyone help me to find out the solution, and sorry in advance to disturb you with the same issue. Cheers, Jewel e-mail:moshiu...@yahoo.com g-mail: mrahmankuf...@gmail.com [[alternative HTML version deleted]]
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