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

> ### Name: filter_obs
> ### Title: Filter observations with a list of conditions
> ### Aliases: filter_obs
> 
> ### ** Examples
> 
> # Filter by row index
> filter_obs(ex_taxmap, "info", 1:2)
<Taxmap>
  17 taxa: b. Mammalia, c. Plantae ... q. lycopersicum, r. tuberosum
  17 edges: NA->b, NA->c, b->d, b->e ... j->o, k->p, l->q, l->r
  4 data sets:
    info:
      # A tibble: 2 x 4
        taxon_id name  n_legs dangerous
        <chr>    <chr>  <dbl> <lgl>    
      1 m        tiger      4 TRUE     
      2 n        cat        4 FALSE    
    phylopic_ids: a named vector of 'character' with 6 items
       m. e148eabb-f138-43[truncated] ... r. 63604565-0406-46[truncated]
    foods: a list of 6 items named by taxa:
       m, n, o, p, q, r
    abund:
      # A tibble: 8 x 5
        taxon_id code  sample_id count taxon_index
        <chr>    <fct> <fct>     <dbl>       <int>
      1 m        T     A             1           1
      2 n        C     A             2           2
      3 o        M     B             5           3
      # ... with 5 more rows
  1 functions:
    reaction
> 
> # Filter by TRUE/FALSE
> filter_obs(ex_taxmap, "info", dangerous == FALSE)
<Taxmap>
  17 taxa: b. Mammalia, c. Plantae ... q. lycopersicum, r. tuberosum
  17 edges: NA->b, NA->c, b->d, b->e ... j->o, k->p, l->q, l->r
  4 data sets:
    info:
      # A tibble: 4 x 4
        taxon_id name   n_legs dangerous
        <chr>    <chr>   <dbl> <lgl>    
      1 n        cat         4 FALSE    
      2 o        mole        4 FALSE    
      3 q        tomato      0 FALSE    
      # ... with 1 more row
    phylopic_ids: a named vector of 'character' with 6 items
       m. e148eabb-f138-43[truncated] ... r. 63604565-0406-46[truncated]
    foods: a list of 6 items named by taxa:
       m, n, o, p, q, r
    abund:
      # A tibble: 8 x 5
        taxon_id code  sample_id count taxon_index
        <chr>    <fct> <fct>     <dbl>       <int>
      1 m        T     A             1           1
      2 n        C     A             2           2
      3 o        M     B             5           3
      # ... with 5 more rows
  1 functions:
    reaction
> filter_obs(ex_taxmap, "info", dangerous == FALSE, n_legs > 0)
<Taxmap>
  17 taxa: b. Mammalia, c. Plantae ... q. lycopersicum, r. tuberosum
  17 edges: NA->b, NA->c, b->d, b->e ... j->o, k->p, l->q, l->r
  4 data sets:
    info:
      # A tibble: 2 x 4
        taxon_id name  n_legs dangerous
        <chr>    <chr>  <dbl> <lgl>    
      1 n        cat        4 FALSE    
      2 o        mole       4 FALSE    
    phylopic_ids: a named vector of 'character' with 6 items
       m. e148eabb-f138-43[truncated] ... r. 63604565-0406-46[truncated]
    foods: a list of 6 items named by taxa:
       m, n, o, p, q, r
    abund:
      # A tibble: 8 x 5
        taxon_id code  sample_id count taxon_index
        <chr>    <fct> <fct>     <dbl>       <int>
      1 m        T     A             1           1
      2 n        C     A             2           2
      3 o        M     B             5           3
      # ... with 5 more rows
  1 functions:
    reaction
> filter_obs(ex_taxmap, "info", n_legs == 2)
<Taxmap>
  17 taxa: b. Mammalia, c. Plantae ... q. lycopersicum, r. tuberosum
  17 edges: NA->b, NA->c, b->d, b->e ... j->o, k->p, l->q, l->r
  4 data sets:
    info:
      # A tibble: 1 x 4
        taxon_id name  n_legs dangerous
        <chr>    <chr>  <dbl> <lgl>    
      1 p        human      2 TRUE     
    phylopic_ids: a named vector of 'character' with 6 items
       m. e148eabb-f138-43[truncated] ... r. 63604565-0406-46[truncated]
    foods: a list of 6 items named by taxa:
       m, n, o, p, q, r
    abund:
      # A tibble: 8 x 5
        taxon_id code  sample_id count taxon_index
        <chr>    <fct> <fct>     <dbl>       <int>
      1 m        T     A             1           1
      2 n        C     A             2           2
      3 o        M     B             5           3
      # ... with 5 more rows
  1 functions:
    reaction
> 
> # Remove taxa whose obserservations were filtered out
> filter_obs(ex_taxmap, "info", n_legs == 2, drop_taxa = TRUE)
<Taxmap>
  4 taxa: b. Mammalia, f. Hominidae, k. homo, p. sapiens
  4 edges: NA->b, b->f, f->k, k->p
  4 data sets:
    info:
      # A tibble: 1 x 4
        taxon_id name  n_legs dangerous
        <chr>    <chr>  <dbl> <lgl>    
      1 p        human      2 TRUE     
    phylopic_ids: a named vector of 'character' with 1 item
       p. 9fae30cd-fb59-4a81-a39c-e1826a35f612
    foods: a list of 1 item named by taxa:
       p
    abund:
      # A tibble: 2 x 5
        taxon_id code  sample_id count taxon_index
        <chr>    <fct> <fct>     <dbl>       <int>
      1 p        H     B             2           4
      2 p        H     B             0           4
  1 functions:
    reaction
> 
> # Preserve other data sets while removing taxa
> filter_obs(ex_taxmap, "info", n_legs == 2, drop_taxa = TRUE,
+            drop_obs = c(abund = FALSE))
Error in `[<-.data.frame`(`*tmp*`, !indexes, "taxon_id", value = NA_character_) : 
  replacement has 1 row, data has 0
Calls: filter_obs ... lapply -> FUN -> <Anonymous> -> [<- -> [<-.data.frame
Execution halted