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

> ### Name: summary.emfrail
> ### Title: Summary for 'emfrail' objects
> ### Aliases: summary.emfrail
> 
> ### ** Examples
> 
> data("bladder")
> mod_gamma <- emfrail(Surv(start, stop, status) ~ treatment + cluster(id), bladder1)
Warning in Surv(start, stop, status) :
  Stop time must be > start time, NA created
Warning in Surv(start, stop, status) :
  Invalid status value, converted to NA
Warning in Surv(start, stop, status) :
  Stop time must be > start time, NA created
Warning in Surv(start, stop, status) :
  Invalid status value, converted to NA
Calculating adjustment for information matrix...
> summary(mod_gamma)
Call: 
emfrail(formula = Surv(start, stop, status) ~ treatment + cluster(id), 
    data = bladder1)

Regression coefficients:
                        coef exp(coef) se(coef) adjusted se        z      p
treatmentpyridoxine  0.14076   1.15115  0.33872     0.33905  0.41556 0.6777
treatmentthiotepa   -0.15888   0.85309  0.33054     0.33123 -0.48068 0.6307
Estimated distribution: gamma / left truncation: FALSE 

Fit summary:
Commenges-Andersen test for heterogeneity: p-val  1.45e-07 
(marginal) no-frailty Log-likelihood: -800.212 
(marginal) Log-likelihood: -763.58 
LRT: 1/2 * pchisq(73.3), p-val 5.67e-18

Frailty summary:
theta = 0.835 (0.21) / 95% CI: [0.523, 1.395]
variance = 1.197 / 95% CI: [0.717, 1.913]
Kendall's tau: 0.374 / 95% CI: [0.264, 0.489]
Median concordance: 0.377 / 95% CI: [0.261, 0.5]
E[log Z]: -0.706 / 95% CI: [-1.207, -0.399]
Var[log Z]: 2.152 / 95% CI: [1.031, 4.576]
Confidence intervals based on the likelihood function
> 
> # plot the Empirical Bayes estimates of the frailty
> # easy way:
> plot(mod_gamma, type = "hist")
> 
> # a fancy graph:
> sum_mod <- summary(mod_gamma)
> library(dplyr)
Warning: S3 methods '[.fun_list', '[.grouped_df', 'all.equal.tbl_df', 'anti_join.data.frame', 'anti_join.tbl_df', 'arrange.data.frame', 'arrange.default', 'arrange.grouped_df', 'arrange.tbl_df', 'arrange_.data.frame', 'arrange_.tbl_df', 'as.data.frame.grouped_df', 'as.data.frame.rowwise_df', 'as.data.frame.tbl_cube', 'as.data.frame.tbl_df', 'as.table.tbl_cube', 'as.tbl.data.frame', 'as.tbl.tbl', 'as.tbl_cube.array', 'as.tbl_cube.data.frame', 'as.tbl_cube.matrix', 'as.tbl_cube.table', 'as_data_frame.grouped_df', 'as_data_frame.tbl_cube', 'auto_copy.tbl_cube', 'auto_copy.tbl_df', 'cbind.grouped_df', 'collapse.data.frame', 'collect.data.frame', 'common_by.NULL', 'common_by.character', 'common_by.default', 'common_by.list', 'compute.data.frame', 'copy_to.DBIConnection', 'copy_to.src_local', 'default_missing.data.frame', 'default_missing.default', 'dim.tbl_cube', 'distinct.data.frame', 'distinct.default', 'distinct.grouped_df', 'distinct.tbl_df', 'distinct_.data.frame', 'distinct_.grouped_df', 'dist [... truncated]
Error: package or namespace load failed for 'dplyr' in namespaceExport(ns, exports):
 undefined exports: add_count, add_count_, add_rownames, add_tally, add_tally_, all_equal, all_vars, anti_join, any_vars, arrange, arrange_, arrange_all, arrange_at, arrange_if, as.tbl, as.tbl_cube, auto_copy, bench_tbls, between, bind_cols, bind_rows, case_when, changes, check_dbplyr, coalesce, collect, combine, common_by, compare_tbls, compare_tbls2, compute, contains, copy_to, count, count_, cumall, cumany, cume_dist, cummean, current_vars, db_analyze, db_begin, db_commit, db_create_index, db_create_indexes, db_create_table, db_data_type, db_desc, db_drop_table, db_explain, db_has_table, db_insert_into, db_list_tables, db_query_fields, db_query_rows, db_rollback, db_save_query, db_write_table, dense_rank, desc, dim_desc, distinct, distinct_, do, do_, dr_dplyr, ends_with, eval_tbls, eval_tbls2, everything, explain, failwith, filter_, filter_all, filter_at, filter_if, first, full_join, funs, funs_, g
Execution halted