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

> ### Name: metaplot
> ### Title: Metaplot
> ### Aliases: metaplot metaplot.folded metaplot_.folded
> 
> ### ** Examples
> 
> # load some packages
> library(spec)
> library(csv)
> library(magrittr)
> library(tidyr)

Attaching package: 'tidyr'

The following object is masked from 'package:magrittr':

    extract

> library(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

> library(fold)
> 
> # find paths to example data and specification
> x <- system.file(package='metaplot','extdata','drug1001.csv')
> spec <- system.file(package='metaplot','extdata','drug1001.spec')
> 
> # verify agreement at file level
> x %matches% spec
[1] TRUE
> 
> # read and verify in memory
> x %<>% as.csv
> spec %<>% as.spec
> x %matches% spec
[1] TRUE
> 
> # convert specifaction to folded format
> spec %<>%  as.folded
> 
> # capture the most interesting parts of x
> x %<>% filter(VISIBLE == 1) %>% filter(EVID == 0)
> 
> # identify keys
> attr(x, 'groups') <- c('ID','TIME')
> 
> # fold x
> x %<>% fold
> 
> # combine with metadata
> x %<>% bind_rows(spec)
> x %<>% sort
> 
> # Now we have a plotting dataset with embedded metadata.
> # We call metaplot with various numbers of continuous and
> # categorical arguments, given as unquoted values from the
> #  VARIABLE column.
> 
> x %>% metaplot(AGE) # one continuous
> x %>% metaplot(PRED,DV) # two continuous
> x %>% metaplot(AGE,SEX) # continuous and categorical
> x %>% metaplot(SEX,AGE) # categorical and continuous
> x %>% metaplot(PRED,DV,SEX) # two continous and categorical
> x %>% metaplot(ETA1,ETA2,ETA3) # three or more continuous
Error in UseMethod("continuous") : 
  no applicable method for 'continuous' applied to an object of class "data.frame"
Calls: %>% ... corsplom.folded -> sapply -> lapply -> FUN -> continuous
Execution halted