I get this error .... on using the, traceback() function :--
> traceback()
10: .Call("La_dgesv", a, b, tol, PACKAGE = "base")
9: solve.default(Szz)
8: solve(Szz)
7: pcor.mat(firstvalue, secondvalue, third_var, method, na.rm = T)
6: PartialCorr_Calculation(value1, value2, third_var, method = "pearson",
na.rm = T)
5: Partial(contrld_third_var(rowvalues$matrix1, rowvalues$matrix2,
x <- stringOfItemCategoryToDataFrameOfItemCategory,
item_category_table,
pcor_type <- "ic"), data1, data2, pcor_thirdvar_type <- "all")
4: main()
3: eval.with.vis(expr, envir, enclos)
2: eval.with.vis(ei, envir)
1: source("correlationFP.R")
what is this error ".*Call("La_dgesv", a, b, tol, PACKAGE = "base")*" how
can i rectify it?
I don't know statistics...going mad ,debugging this problem..
any help is highly appreciated !! :)
Thanks in advance
Moumita
On Thu, Jun 25, 2009 at 8:29 PM, Moumita Das
<[email protected]>wrote:
>
> I get this error while computing partial correlation.
>
>
> *Error in solve.default(Szz) :
> system is computationally singular: reciprocal condition number =
> 4.90109e-18*
>
> Why is it?Can anyone give me some idea ,how do i get rid it it?
>
> This is the function i use for calculating partial correlation.
>
>
> pcor.mat <- function(x,y,z,method="p",na.rm=T){
>
>
> x <- c(x)
> y <- c(y)
> z <- as.data.frame(z)
>
>
>
> if(dim(z)[2] == 0){
> stop("There should be given data\n")
> }
>
> data <- data.frame(x,y,z)
>
> if(na.rm == T){
> data = na.omit(data)
> }
>
> xdata <- na.omit(data.frame(data[,c(1,2)]))
> Sxx <- cov(xdata,xdata,m=method)
>
> xzdata <- na.omit(data)
> xdata <- data.frame(xzdata[,c(1,2)])
> zdata <- data.frame(xzdata[,-c(1,2)])
> Sxz <- cov(xdata,zdata,m=method)
>
> zdata <- na.omit(data.frame(data[,-c(1,2)]))
> Szz <- cov(zdata,zdata,m=method)
>
>
> # is Szz positive definite?
> zz.ev <- eigen(Szz)$values
> if(min(zz.ev)[1]<0){
>
> stop("\'Szz\' is not positive definite!\n")
> }
>
> # partial correlation
> Sxx.z <- Sxx - Sxz %*% solve(Szz) %*% t(Sxz)
>
> print(Sxx.z) # this gets printed
>
> rxx.z <- cov2cor(Sxx.z)[1,2] #some problem in this function
> function (V)
> {
> print("cov2cor")
> p <- (d <- dim(V))[1]
> if (!is.numeric(V) || length(d) != 2L || p != d[2L])
> stop("'V' is not a square numeric matrix")
> Is <- sqrt(1/diag(V))
> if (any(!is.finite(Is)))
> warning("diag(.) had 0 or NA entries; non-finite result is
> doubtful")
> r <- V
> r[] <- Is * V * rep(Is, each = p)
> r[cbind(1L:p, 1L:p)] <- 1
> r
> }
> return(rxx.z)
> }
>
> --
> Thanks
> Moumita
>
--
Thanks
Moumita
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