Calculations in RShiny - r

Question

I’m super new to RShiny and I’m trying to create an app that will calculate the total meters players will run during practice. I have a csv file in which I have meters per minute for each drill and I want this app to calculate the total based on the drills selected and the time selected.
And I don’t know how to pull the data from the csv file for the specific drill selected and multiply it by the number of minutes selected.
This is what I have right now but it doesn’t work.
ui <- fluidPage(
titlePanel("Practice Planner"),
sidebarLayout(
sidebarPanel(
numericInput("num", h3("Number of Drills"), value = 1)
),
mainPanel(
selectInput("DrillName",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider11",
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
conditionalPanel(
condition = "input.num > '1'",
selectInput("Drill Name",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider1",
label = h3("Slider"),
min = 0,
max = 60,
value = 0)),
conditionalPanel(
condition = "input.num > '2'",
selectInput("Drill Name",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider1",
label = h3("Slider"),
min = 0,
max = 60,
value = 0)),
conditionalPanel(
condition = "input.num > '3'",
selectInput("Drill Name",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider1",
label = h3("Slider"),
min = 0,
max = 60,
value = 0)),
conditionalPanel(
condition = "input.num > '4'",
selectInput("Drill Name",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider1",
label = h3("Slider"),
min = 0,
max = 60,
value = 0)),
conditionalPanel(
condition = "input.num > '5'",
selectInput("Drill Name",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider1",
label = h3("Slider"),
min = 0,
max = 60,
value = 0)),
textOutput("MpM1")
)
)
)
# Define server logic ----
server <- function(input, output, session) {
output$MpM1 <- renderText({
chosendrill <- (input$DrillName)
MpM <- unique.data.frame(MyData$MetersPerMinute)
MpM1 <- (MpM[[chosendrill]]) * (input$slider11)
})
}
# Create Shiny app ----
shinyApp(ui = ui, server = server)

Answer 1

I'm not certain of a lot of details of what you are looking for, and I don't have your data set, but I think I was able to come up with a relatively simple update of your app to hopefully show how to make it work. First, I made a test dataset, which I just used mtcars and renamed some columns to match yours. Then I wrote the file, then read it in, so that way I can show how one can read data for a shiny app. Otherwise, if you are looking to have more dynamic read in of data, refer to #r2evans comment on shiny::fileInput, or maybe even a reactiveFileReader.
The next thing I did was update the inputId of many of your inputs, as you used the same name for different inputs. As I expect you want each input to do something different, a different inputId is needed. Additionally, I put a new textOutput for each conditionalPanel, so that each can display their own data. I also added some spacing for visual clarity with br().
For the server side, I changed a couple of things. First, I have never used unique.data.frame, but I have used distinct from dplyr, so I used that instead. Then, I changed your MpM_text, I'm nto really certain what exactly you wanted to happen, but this shows how to use rows that match the input and to use them to multiply against something else. This was then output in a paste0.
I also did a repeat of this for the other 5 drills that were in the conditionalPanel, just as a little show of how you can repeat the calculations with different inputs/outputs. Again, I'm not sure what the precise nature of your program/data, but hopefully this helps to point you in the right direction. If you are posting on stack in the future, I'd suggest making your code as simple as possible that will show whatever error you are seeing, including any necessary data so that the viewers can easily recreate your issue. Best of luck, shiny can be a pain sometimes to figure out, but I've really enjoyed using it over the years and so I hope you have success yourself!
library(shiny)
library(dplyr)
MyData<-mtcars%>% #Since I don't have your dataset, I made my own using mtcars
rename(Drill = cyl, #Renaming column names to match yours
MetersPerMinute = mpg)
write.table(MyData, "Test.csv") #Writing it into a csv so I can demonstrate how to read and use the data from a csv
MyData<-read.table("Test.csv") #reading the csv
ui <- fluidPage(
titlePanel("Practice Planner"),
sidebarLayout(
sidebarPanel(
numericInput("num", h3("Number of Drills"), value = 1)
),
mainPanel(
selectInput("DrillName",
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider11",
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
textOutput("MpM1"),
br(), #Spacing for clarity
conditionalPanel(
condition = "input.num > '1'",
selectInput("DrillName1", #name of the select input should differ if expecting to be used separately, changed to `DrillName1`
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider1",
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
textOutput("MpM2")),
br(), #Spacing for clarity
conditionalPanel(
condition = "input.num > '2'",
selectInput("DrillName2", #name of the select input should differ if expecting to be used separately, changed to `DrillName2`
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider2", #name of the sliderinput should differ if expecting to be used separately, changed to 2
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
textOutput("MpM3")),
br(), #Spacing for clarity
conditionalPanel(
condition = "input.num > '3'",
selectInput("DrillName3", #name of the select input should differ if expecting to be used separately, changed to `DrillName3`
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider3", #name of the sliderinput should differ if expecting to be used separately, changed to 3
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
textOutput("MpM4")),
br(), #Spacing for clarity
conditionalPanel(
condition = "input.num > '4'",
selectInput("DrillName4", #name of the select input should differ if expecting to be used separately, changed to `DrillName4`
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider4", #name of the sliderinput should differ if expecting to be used separately, changed to 4
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
textOutput("MpM5")),
br(), #Spacing for clarity
conditionalPanel(
condition = "input.num > '5'",
selectInput("DrillName5", #name of the select input should differ if expecting to be used separately, changed to `DrillName5`
label = "Choose a Drill:",
choices = unique(MyData$Drill),
selected = NULL,
multiple = FALSE),
sliderInput("slider5", #name of the sliderinput should differ if expecting to be used separately, changed to 5
label = h3("Slider"),
min = 0,
max = 60,
value = 0),
textOutput("MpM6"))
)
)
)
# Define server logic ----
server <- function(input, output, session) {
output$MpM1 <- renderText({
chosendrill <- (input$DrillName)
# MpM <- unique.data.frame(MyData$MetersPerMinute) #This doesn't work for me. I've never used unique.data.frame though.
# Instead I'll use distinct from dplyr, which is considerably faster, according to dplyr!
MpM <- MyData%>%
distinct(MetersPerMinute, .keep_all = T)
MpM_text <- (MpM$MetersPerMinute[MpM$Drill == chosendrill]) * (input$slider11)
#I'm not certain what the data looks like, or what the result you want should look like
# In the mtcars dataset I used for example, it has multiple matches to each cyl, or "Drill", so this will put multiple outputs
paste0("Drill Meters per minute * slider: ", paste0(MpM_text, collapse = " "))
})
lapply(2:6, function(x) { #This is just showing how to repeat the calculations for multiple sliders
output[[paste0("MpM", x)]] <- renderText({
chosendrill <- input[[paste0("DrillName",x-1)]]
MpM <- MyData%>%
distinct(MetersPerMinute, .keep_all = T)
MpM_text <- (MpM$MetersPerMinute[MpM$Drill == chosendrill]) * (input[[paste0("slider",x-1)]])
paste0("Drill Meters per minute * slider: ", paste0(MpM_text, collapse = " "))
})
})
}
# Create Shiny app ----
shinyApp(ui = ui, server = server)