Running examples in ‘mosaicData-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: Birthdays
> ### Title: US Births in 1969 - 1988
> ### Aliases: Birthdays
> 
> ### ** Examples
> 
> data(Birthdays)
> if (require(mosaic)) {
+   MI <- Birthdays %>% filter(state == "MI")
+   gf_point(births ~ date, Birthdays, data = MI) 
+   gf_line(births ~ date, Birthdays, data = MI, color = ~ wday)
+   gf_line(births ~ date, 
+     data = Birthdays %>% group_by(date) %>% summarise(births = sum(births)))
+   }
Loading required package: mosaic
Loading required package: dplyr

Attaching package: ‘dplyr’

The following objects are masked from ‘package:stats’:

    filter, lag

The following objects are masked from ‘package:base’:

    intersect, setdiff, setequal, union

Loading required package: lattice
Loading required package: ggformula
Loading required package: ggplot2
Loading required package: ggstance

Attaching package: ‘ggstance’

The following objects are masked from ‘package:ggplot2’:

    GeomErrorbarh, geom_errorbarh


New to ggformula?  Try the tutorials: 
	learnr::run_tutorial("introduction", package = "ggformula")
	learnr::run_tutorial("refining", package = "ggformula")
Loading required package: Matrix

The 'mosaic' package masks several functions from core packages in order to add 
additional features.  The original behavior of these functions should not be affected by this.

Note: If you use the Matrix package, be sure to load it BEFORE loading mosaic.

Attaching package: ‘mosaic’

The following object is masked from ‘package:Matrix’:

    mean

The following object is masked from ‘package:ggplot2’:

    stat

The following objects are masked from ‘package:dplyr’:

    count, do, tally

The following objects are masked from ‘package:stats’:

    IQR, binom.test, cor, cor.test, cov, fivenum, median, prop.test,
    quantile, sd, t.test, var

The following objects are masked from ‘package:base’:

    max, mean, min, prod, range, sample, sum

Error in grid.Call.graphics(C_setviewport, vp, TRUE) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'double'
Calls: <Anonymous> ... lapply -> FUN -> push.vp.viewport -> grid.Call.graphics
Execution halted