pepijn-devries

## use the magick package to read a GIF file:
library(magick)

## use AmigaFFH to convert into Amiga IFF file,
## make sure to use version 0.2.0 or newer:
library(AmigaFFH)

## Read the GIF animation we created in an earlier post:
earth <- image_read("http://3.bp.blogspot.com/-CCurVbm1ChI/VdC2NrqeeaI/AAAAAAAAx_8/lyO9mFyVhU8/s1600/globe.gif")

pepijn-devries

## Library to handle Amiga files
library(AmigaFFH)
## Library to handle png-images
library(png)

## Download an image of the Amiga boing ball:
con <- url("http://www.f1-software.com/images/icons/amiga-boing-ball.png", "rb")
logo <- readBin(con, "raw", 100000L)
close(con)
logo <- as.raster(readPNG(logo))

pepijn-devries

# This part of the code runs on a Shiny server and interacts with the
# user interface shown at the client's side.
# For details and tutorials go to http://shiny.rstudio.com

server <- shinyServer(function(input, output, server) {
  # Make these character strings 'reactive'. That way
  # the output text is automatically update when these
  # values are changed.
  values <- reactiveValues(state = c("Interface1: Waiting for clicks",
                                      "Interface2: Waiting for clicks"))

pepijn-devries

# This part of the code generates the user interface show at the client's side.
# For details and tutorials go to http://shiny.rstudio.com

ui <- shinyUI(fluidPage(
  # This adds a tiny bit of javascript to the client side's web page.
  # It defines a global variable 'negator', which is negated when
  # the javascript function negate() is called.
  # This can be used to trick Shiny's event observers.
  tags$head(tags$script("var negator=1;
                        function negate() {

pepijn-devries

## Required libraries for this example
library(png)
library(sp)
library(maptools)
library(raster)

## A function as a wrapper around 4 of the 5 steps
## described in the main text of the blog....
## As input it requires a SpatialPolygons object
## and the URL to the png image that will be used

pepijn-devries

## package for handling spatial data:
library(sp)
## package that contains simple world map data
library(maptools)
## package for modifying spatial data:
library(rgeos)
## package used for setting up clipping areas
library(raster)

## function that segments the polygons of SpatialPolygons(DataFrame) object

pepijn-devries

require(pscl)

# the vuong test returns NULL. Lines below will modify the function to return the output table:
# Turn the vuong-function into text:
vuong2 <- deparse(vuong)
# remove the current return statement:
vuong2 <- vuong2[!grepl("return", vuong2)]
# instead of printing the output, return it!:
vuong2 <- gsub("print(out)", "return(out)", vuong2, fixed = T)
# now change the text back into an actual function that can be called:

pepijn-devries

## This package is used to retrieve data from openstreetmap.org:
require(osmar)
## This pacakge is used to process the spatial data:
require(rgeos)
## This package is used to convert the data from openstreetmap into something workable:
require(maptools)

## function to retrieve a relation from openstreetmap and convert it
## into a SpatialPolygons object:
OSM_relation_to_SP <- function(rel) {

pepijn-devries

require(raster)
require(KernSmooth)
require(maptools)

## load the simulation results. See the previous blog post
## how this file was created. This data file contains
## an object named 'part.results', which is a list
## of SpatialPointsDataFrame objects.
load("output/out.RData")

pepijn-devries

## load required packages:
require(sp)
require(raster)
require(ncdf4)
require(ncdf.tools)
require(rgeos)
require(maptools)

###############################################################
## STEP 1: load the water currents and wind data