circlize package: some error message

I recently tried to run some sample code from  R package: circlize,
and got an error message (please see below) ===== > library(circlize) > circos.genomicInitialize(df) > df = data.frame(name = c("TP53", "TP63", "TP73"), + start = c(7565097, 189349205, 3569084),
+ end = c(7590856, 189615068, 3652765),
+ stringsAsFactors = FALSE) > df name     start       end
1 TP53   7565097   7590856
2 TP63 189349205 189615068
3 TP73   3569084   3652765 > circos.genomicInitialize(df) > circos.clear() > circos.genomicInitialize(df, major.by = 10000) Error in seq.default(xlim[1], 10^nchar(round(max(x2 - x1 + 1))), by =
major.by) : wrong sign in 'by' argument === And my session information: > sessionInfo() R version 3.1.1 (2014-07-10)
Platform: x86_64-unknown-linux-gnu (64-bit) locale: [1] LC_CTYPE=en_US.utf8       LC_NUMERIC=C [3] LC_TIME=en_US.utf8        LC_COLLATE=C [5] LC_MONETARY=en_US.utf8    LC_MESSAGES=en_US.utf8 [7] LC_PAPER=en_US.utf8       LC_NAME=C [9] LC_ADDRESS=C              LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.utf8 LC_IDENTIFICATION=C attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base other attached packages:
[1] circlize_0.1.0 loaded via a namespace (and not attached): [1] AnnotationDbi_1.26.0    Biobase_2.24.0          BiocGenerics_0.10.0 [4] DBI_0.2-7               DESeq2_1.4.5            GenomeInfoDb_1.0.2 [7] GenomicRanges_1.16.3    IRanges_1.22.9          RColorBrewer_1.0-5
[10] RSQLite_0.11.4          Rcpp_0.11.2             RcppArmadillo_0.4.320.0
[13] XML_3.98-1.1            XVector_0.4.0           annotate_1.42.1
[16] genefilter_1.46.1       geneplotter_1.42.0      grid_3.1.1
[19] lattice_0.20-29         locfit_1.5-9.1          parallel_3.1.1
[22] splines_3.1.1           stats4_3.1.1            survival_2.37-7
[25] xtable_1.7-3 > ===

Wonder anyone could please help me out with this?

Thank you very much for your time.:)

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