johndrummond

# lookup_list_vs_env.R
# comparing the performance of lookups with lists as opposed to 
# environments in R. As the size of the collection increases, the better
# performance of the environments for lookups is multiples better.
library(microbenchmark)
library(purrr)
library(stringr)

e1 <- new.env()
l1 <- list()

johndrummond

#
# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(shiny)

johndrummond

# oberveEvent includes the ability of the first parameter to be an expression. But if the return value of that expression is 
# null, the ignore null setting blocks updates, even though other parts of the expression are updating.
# in the example below with the default settings, button Event1 will only trigger the update of "observeEvent either button"
# after Event2 has been pushed at least once

library(shiny)

# Define UI for application that draws a histogram
ui <- fluidPage(

johndrummond

library(shiny)
library(DT)
library(dplyr)
library(future)
library(magrittr)
plan(multiprocess)

dedupe <- function(r) {
  makeReactiveBinding("val")
  observe(val <<- r(), priority = 10)

johndrummond

# notice the flush on the single user holds up the user updating, as the promise and reactive variable is there per user

library(shiny)
library(DT)
library(dplyr)
library(future)
library(promises)
plan(multiprocess)

ui <- fluidPage(

johndrummond

library(shiny)
library(DT)
library(dplyr)
library(future)
library(promises)
plan(multiprocess)

ui <- fluidPage(
    verbatimTextOutput("timer"),
    DTOutput("myTable")

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# 
#

library(shiny)

# Define UI for application that draws a histogram
ui <- fluidPage(

    # Application title
    titlePanel("Reactive values updating"),

johndrummond

#
# This is a Shiny web application. 
# with a handler that returns plain json
# run and in a browser look for /health/
# e.g. http://127.0.0.1:5732/health/
# from https://stackoverflow.com/users/1455889/amaurel
# on https://stackoverflow.com/questions/19991654/shiny-server-print-json-as-a-result-output
# You can run the application by clicking
# the 'Run App' button above.
#

johndrummond

# This was an attempt to return json on /health/ with shiny.router
# https://appsilon.com/shiny-router-package/
# trying https://stackoverflow.com/users/7268834/slavakx 's suggestion
# https://stackoverflow.com/questions/19991654/shiny-server-print-json-as-a-result-output 
# but the json is already wrapped
library(shiny)
library(shiny.router)
library(data.table)
library(jsonlite)

johndrummond

# samples of some joins of data.tables with trivial tables


library(data.table)
dt1 <- data.table(f1=1:5, f2=sample(letters,5))
dt2 <- data.table(f1=2:6, f3=sample(letters,5))
dt3 <- data.table(f1=c(2,2:6), f3=sample(letters,6))
dt1
dt2
dt3