Error for fscatterplot example with flat=TRUE

[tomsing1]

https://github.com/facileverse/FacileViz/blob/3c66ec6247bbb3fc013181ee1cd766f692faa515/R/fscatterplot.R#L41

fscatterplot(dat, c("a", "b", "c"), flat = TRUE, color_aes = "class", 
    hover = c("class", "c"))
Error in if (nGuides > 1) { : missing value where TRUE/FALSE needed

Note: the example without flat = TRUE succeeds.

SessionInfo

sessionInfo()
R version 3.6.0 (2019-04-26)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS Mojave 10.14.6

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] FacileViz_0.1.5    BiocManager_1.30.4 devtools_2.1.0     usethis_1.5.1     

loaded via a namespace (and not attached):
  [1] colorspace_1.4-1         rjson_0.2.20             rprojroot_1.3-2          circlize_0.4.8          
  [5] GlobalOptions_0.1.0      fs_1.3.1                 clue_0.3-57              rstudioapi_0.10         
  [9] remotes_2.1.0            bit64_0.9-7              AnnotationDbi_1.46.0     splines_3.6.0           
 [13] knitr_1.25               geneplotter_1.62.0       shinythemes_1.1.2        pkgload_1.0.2           
 [17] zeallot_0.1.0            jsonlite_1.6             broom_0.5.2              annotate_1.62.0         
 [21] cluster_2.1.0            png_0.1-7                graph_1.62.0             shiny_1.3.2             
 [25] compiler_3.6.0           httr_1.4.1               backports_1.1.4          assertthat_0.2.1        
 [29] Matrix_1.2-17            lazyeval_0.2.2           limma_3.40.6             cli_1.1.0               
 [33] multiGSEA_0.12.14        later_0.8.0              htmltools_0.3.6          prettyunits_1.0.2       
 [37] tools_3.6.0              gtable_0.3.0             glue_1.3.1               reshape2_1.4.3          
 [41] dplyr_0.8.3              Rcpp_1.0.2               Biobase_2.44.0           vctrs_0.2.0             
 [45] nlme_3.1-140             crosstalk_1.0.0          DelayedMatrixStats_1.6.0 FacileData_0.10.5       
 [49] xfun_0.9                 stringr_1.4.0            ps_1.3.0                 testthat_2.1.1          
 [53] mime_0.7                 lifecycle_0.1.0          irlba_2.3.3              XML_3.98-1.20           
 [57] edgeR_3.26.6             scales_1.0.0             promises_1.0.1           parallel_3.6.0          
 [61] rhdf5_2.28.0             RColorBrewer_1.1-2       yaml_2.2.0               ComplexHeatmap_2.0.0    
 [65] memoise_1.1.0            gridExtra_2.3            ggplot2_3.2.1            stringi_1.4.3           
 [69] RSQLite_2.1.2            GSVA_1.32.0              S4Vectors_0.22.0         desc_1.2.0              
 [73] checkmate_1.9.4          BiocGenerics_0.30.0      pkgbuild_1.0.3           BiocParallel_1.18.0     
 [77] shape_1.4.4              rlang_0.4.0              pkgconfig_2.0.3          matrixStats_0.54.0      
 [81] bitops_1.0-6             lattice_0.20-38          purrr_0.3.2              Rhdf5lib_1.6.0          
 [85] htmlwidgets_1.3          bit_1.1-14               processx_3.4.1           tidyselect_0.2.5        
 [89] GSEABase_1.46.0          plyr_1.8.4               magrittr_1.5             R6_2.4.0                
 [93] IRanges_2.18.1           generics_0.0.2           DelayedArray_0.10.0      DBI_1.0.0               
 [97] pillar_1.4.2             withr_2.1.2              survival_2.44-1.1        RCurl_1.95-4.12         
[101] tibble_2.1.3             crayon_1.3.4             plotly_4.9.0             viridis_0.5.1           
[105] GetoptLong_0.1.7         locfit_1.5-9.1           grid_3.6.0               data.table_1.12.2       
[109] blob_1.2.0               callr_3.3.1              digest_0.6.21            xtable_1.8-4            
[113] tidyr_1.0.0              httpuv_1.5.2             stats4_3.6.0             munsell_0.5.0           
[117] viridisLite_0.3.0        fortunes_1.5-4           sessioninfo_1.1.1