Creating a vector of inputs with length equal to the number of inputs defined by the user

I have a dynamic numericInput - i.e. the number of numericInput's displayed in the UI depends on the some other user-defined variable "num", i.e.:

In UI:


In server:

  output$out  <- renderUI({ 
        num <- input$num
        lapply(1:num, function(i) {
          numericInput(inputId = paste0("input_",i),
                       label   = h5(paste0("Input number",i)), 
                       value   = 0)

Now also in server, I then need shiny to create a vector which contains all of the inputs.

E.g., if num=2, I need shiny to create a vector such that:

my_vec_1 <- c(input$input_1, input$input_2)

This vector will then be part of a list, which contains other vectors which will be generated through the same process:

my_list <- list(my_vec_1, my_vec_2, ... etc...)

The reason that these vectors need to be part of a list is that they will be used as parameters for prior distributions using rstan.

I have tried to do it using paste0 and, like this:

my_vec_1 <- c()
for (i in 1:num) { 
     my_vec_1[i] <- paste0("input$input_",i)  

as_name_vec <- Vectorize(, SIMPLIFY = TRUE)
my_vec_1 <-  as_name_vec(my_vec_1)
my_list <- list(my_vec_1, my_vec_2, ... etc...)

However, I get an error: "Error in data_list2array(x) : all elements of the list should be numeric".

Note: If the number of inputs was fixed (e.g., let's say 2 inputs for vector #1 and 1 for vector #2), this would be very easy - I could just do something like this:

my_vec_1 <- c(input$input_1, input$input_2)
my_vec_2 <- c(input$input_1)

my_list <- list(my_vec_1, my_vec_2)

I was wondering if anybody has any suggestions?


for (i in 1:num) { 
     my_vec_1[i] <- input[[paste0("input_",i) ]]

and no need for any business.

1 Like

Thank you! that worked

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