dholstius

# See http://stackoverflow.com/questions/29310962/variant-of-rgeosgunion-that-wont-dissolve-adjacent-polygons
# for the relevant problem formulation.

library(sp)

unit_rect <- cbind(
  x = c(0, 0, 1, 1, 0),
  y = c(0, 1, 1, 0, 0))
 
translate <- function (spobj, delta = c(0, 0)) {

dholstius

---
title: "Reactive Leaflet"
author: "David Holstius"
date: "April 16, 2015"
output: html_document
runtime: shiny
---

## Problem Description

dholstius

  extract_substrings <- function (x, ...) {
    make_extractor <- function (i) {
      #message(min(i), " to ", max(i))
      function (s) substr(s, min(i), max(i))
    }
    extractors <- lapply(list(...), make_extractor)
    lapply(extractors, function (f) f(x))
  }
  
  ALPHABET <- paste0(LETTERS, collapse = "")

dholstius

library(ensurer)

ensure_none_missing <- ensures_that(!any(is.na(.)) ~ "There are missing values")
ensure_all_positive <- ensures_that(all(int(.)) > 0 ~ "Not all values are positive", +ensure_none_missing)

# Everything works as expected with a simple vector
x <- 1:4
x %>% ensure_all_positive

# Now let's try testing element(s) of a data.frame

dholstius

#' Patch data on the fly.
#'
#' @param object  to be patched
#' @param cond    logical condition(s) to be evaluated within scope of object
#' @param \dots   name-value pairs
#' @param quiet   suppress messages
#'
#' @examples
#'   patch(mtcars, where(vs == 0, am == 1), gear = Inf, carb = carb + 10)
#'

dholstius

#' (Left) join with a custom comparator
#'
#' @param left  data.frame
#' @param right data.frame
#' @param by    names of columns to join by
#' @param fun   custom comparator (see examples)
#'
#' @examples
#' my_df <- data.frame(cyl = c(4, 4, 6, 8), vs = c(0, 1, NA, NA), foo = c("A", "B", "C", "D"))
#' my_fun <- function (e1, e2) (e1 == e2) | is.na(e2)

dholstius

# via https://support.rstudio.com/hc/en-us/articles/200552326-Running-RStudio-Server-with-a-Proxy

user nginx;
worker_processes 4;
# daemon off;
pid /run/nginx.pid;

events {
        worker_connections 768;
        # multi_accept on;

dholstius

install_from_source <- function (pkg, args = NULL, repos = "http://cran.rstudio.com", overwrite = FALSE, ...) {
  
  if (!overwrite) {
    if (pkg %in% installed.packages()) {
      message(pkg, " is already installed")
      return()
     }
   }
  
  install.packages(

dholstius

#' Filter (subset) a Spatial*DataFrame object
#'
#' @param object a \code{Spatial*DataFrame}
#' @param ... see \link{subset}
#' @param .dots
#'
#' @importFrom lazyeval all_dots lazy_eval
#'
#' @return a subset of the original \code{Spatial*DataFrame}
#'

dholstius

library(ensurer) # awesome

# Example 1 --- OK
groceries <- c("eggs", "bread", "milk")
check_that(groceries, "bread" %in% .)

# Example 2 --- :-(
# I'd really like this to work! It's quite readable.
# Doesn't work b/c `ensurer` (v1.1) doesn't first evaluate calls.
contains <- function (what) function (x) { what %in% x }