Reactive subset in ddply for rmarkdown shiny
问题 I am trying to calculate and plot % yield of some data based on user definable inputs. I am using rmarkdown and shiny to do this. I keep getting stuck when passing a reactive subset through ddply to count the number of rows in the subset.."invalid (null) left side of assignment". Here is an example data set: --- title: "Yield3" author: "P Downs" date: "Tuesday, May 26, 2015" output: html_document runtime: shiny --- # Create user input for reactive subsetting ```{r echo=FALSE} sliderInput(