Running examples in 'biogram-Ex.R' failed
The error most likely occurred in:

> ### Name: plot.criterion_distribution
> ### Title: Plot criterion distribution
> ### Aliases: plot.criterion_distribution
> 
> ### ** Examples
> 
> target_feature <- create_feature_target(10, 375, 15, 600) 
> example_result <- distr_crit(target = target_feature[,1], 
+                              feature = target_feature[,2])
> plot(example_result)
> 
> # a ggplot2 plot
> library(ggplot2)
> ggplot_distr <- function(x) {
+ b <- data.frame(cbind(x=as.numeric(rownames(attr(x, "plot_data"))), 
+                       attr(x, "plot_data")))
+ d1 <- cbind(b[,c(1,2)], attr(x, "nice_name"))
+ d2 <- cbind(b[,c(1,3)], "Probability")
+ colnames(d1) <- c("x", "y", "panel")
+ colnames(d2) <- c("x", "y", "panel")
+ d <- rbind(d1, d2)
+ p <- ggplot(data = d, mapping = aes(x = x, y = y)) + 
+   facet_grid(panel~., scale="free") + 
+   geom_freqpoly(data= d2, aes(color=y), stat = "identity") + 
+   scale_fill_brewer(palette = "Set1") + 
+   geom_point(data=d1, aes(size=y), stat = "identity") + 
+   guides(color = "none") + 
+   guides(size = "none") + 
+   xlab("Number of cases with feature=1 and target=1") + ylab("")
+ p
+ }
> ggplot_distr(example_result)
Error in namespaceExport(ns, exports) : 
  undefined exports: %s!=%, %s!==%, %s+%, %s<%, %s<=%, %s==%, %s===%, %s>%, %s>=%, %stri!=%, %stri!==%, %stri+%, %stri<%, %stri<=%, %stri==%, %stri===%, %stri>%, %stri>=%, stri_datetime_add<-, stri_sub<-, stri_subset<-, stri_subset_charclass<-, stri_subset_coll<-, stri_subset_fixed<-, stri_subset_regex<-, stri_c, stri_c_list, stri_cmp, stri_cmp_eq, stri_cmp_equiv, stri_cmp_ge, stri_cmp_gt, stri_cmp_le, stri_cmp_lt, stri_cmp_neq, stri_cmp_nequiv, stri_compare, stri_conv, stri_count, stri_count_boundaries, stri_count_charclass, stri_count_coll, stri_count_fixed, stri_count_regex, stri_count_words, stri_datetime_add, stri_datetime_create, stri_datetime_fields, stri_datetime_format, stri_datetime_fstr, stri_datetime_now, stri_datetime_parse, stri_datetime_symbols, stri_detect, stri_detect_charclass, stri_detect_coll, stri_detect_fixed, stri_detect_regex, stri_dup, stri_duplicated, stri_duplicated_any, stri_enc_detect, stri_enc_detect2, stri_enc_fromutf32, stri_enc_get, stri_enc_inf
Calls: <Anonymous> ... tryCatch -> tryCatchList -> tryCatchOne -> <Anonymous>
Execution halted