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

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: WqData-class
> ### Title: Class WqData
> ### Aliases: WqData-class WqData-class [,WqData-method
> ###   summary,WqData-method plot,WqData-method
> ### Keywords: classes
> 
> ### ** Examples
> 
> 
> showClass("WqData")
Class "WqData" [package "wql"]

Slots:
                                                                  
Name:                .Data               names           row.names
Class:                list           character data.frameRowLabels
                          
Name:             .S3Class
Class:           character

Extends: 
Class "data.frame", directly
Class "list", by class "data.frame", distance 2
Class "oldClass", by class "data.frame", distance 2
Class "vector", by class "data.frame", distance 3
> # Construct the WqData object sfb as shown in the wqData examples.
> sfb <- wqData(sfbay, c(1,3,4), 5:12, site.order = TRUE, type = "wide", 
+               time.format = "%m/%d/%Y")
> # Summarize the data
> summary(sfb)
      time             site           depth           variable    
 Min.   :1985-01-23   s21:23933   Min.   : 0.500   sal    :23172  
 1st Qu.:1993-04-15   s24:15348   1st Qu.: 3.000   temp   :23156  
 Median :1996-06-12   s27:18122   Median : 6.000   chl    :22063  
 Mean   :1996-07-24   s30:20445   Mean   : 6.836   spm    :16463  
 3rd Qu.:2000-07-13   s32:16905   3rd Qu.:10.000   dox    :15505  
 Max.   :2004-12-14   s36: 7973   Max.   :20.000   nox    :  807  
                                                   (Other): 1560  
     value       
 Min.   :  0.01  
 1st Qu.:  7.50  
 Median : 13.90  
 Mean   : 17.78  
 3rd Qu.: 23.00  
 Max.   :983.00  
                 
> # Create boxplot summary of data
> plot(sfb, vars = c('chl', 'dox', 'spm'), num.col = 2)
Error in Summary.unit(c(4.4, 4.4), na.rm = FALSE) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'double'
Calls: <Anonymous> ... render_strips -> build_strip -> ggstrip -> Summary.unit
Execution halted