var_y_HT examples - error in filter()

[ksauby]

Fix examples so that they can be uncommented. The R error was:

Z_summary <- Z %>% group_by(NetworkID) %>%

• summarise(

•   m = m[1],
  

•   y_total = sum(y_value, rm.na=TRUE)
  

•   ) %>%
  

•   dplyr::filter(NetworkID > 0)
  

Error in dplyr::filter():
! Problem while computing ..1 = NetworkID > 0.
Caused by error:
! object 'NetworkID' not found