In trosendal/svis: Package to produce visualizations on the web

Description of generating a few point maps

The package can generate a simple point map with one or more layers. First we can get the sample data:

library(svis)
## Get the sample data
pts <- sample_data()

## This is a SpatialPointsDataFrame and then then be ploted with the sp package
library(sp)
plot(pts)

This data also contains covariates in the pts@data slot , which describes each point in the data.

str(pts@data[,1:7])

The map contains a function that runs on each feature that returns a popuptext. We need to define this in the data as a variable named pts@data$popup_text. We will put the Status of the dot in that variable so we can see that text in the map popup.

pts@data$popup_text <- pts@data$Status
head(pts@data$Status)

Make a point make with one layer

Now we can make a layer with those points and put it in a map

## Convert to layer object
layer1 <- layer(pts)

## Generate the page header
header <- page_header()

## Map with a single layer:
body <- page_body(map_div(layer1))
page <- page_page(header, body)
map <- tempfile(fileext = "html")
capture.output(page, file = map)

Then view the page

browseURL(map)

## Tricky here: During the build of thé vignette, I place the map file
## in the do folder. Then include it in an iframe as the basename(map)
## because when you view the vignette you are working in the local
## dir.
map <- "../inst/doc/map1.html"
capture.output(page, file = map)
knitr::include_url(basename(map), height = "1000px")

Make a point map with several layers

## The first layer
pts <- sample_data("cwd")
pts@data$popup_text <- pts@data$Status

## And a second layer
pts2 <- sample_data("asf")
## Add some popup text
pts2@data$popup_text <- paste(pts2@data[,"K\u00F6n"], pts2@data$Status)

Now we can make a layer with those points and put it in a map

## Convert to layer objects with 2 different names:
layer1 <- layer(pts, layer_title = "CWD")
layer2 <- layer(pts2, layer_title = "ASF", fillColor = shQuote("#ff0000"))
layersob <- layers(list(layer1, layer2))

## Generate the page header
header <- page_header()

## Map with a single layer:
body <- page_body(map_div(layersob))
page <- page_page(header, body)
map <- tempfile(fileext = "html")
capture.output(page, file = map)

Then view the page

browseURL(map)

map <- "../inst/doc/map2.html"
capture.output(page, file = map)
knitr::include_url(basename(map), height = "1000px")

Make a map with multiple colours based on a variable

pts <- sample_data()
## Your variable of interest should be a factor
pts@data$Djurslag <- as.factor(pts@data$Djurslag)
## We'll put the species in the popuptext too
pts@data$popup_text <- pts@data$Djurslag
## Create a layer
layer1 <- layer(pts, layer_title = "CWD", byvar = "Djurslag")
## Plot it:
header <- page_header()
body <- page_body(map_div(layer1))
page <- page_page(header, body)
map <- tempfile(fileext = "html")
capture.output(page, file = map)

Then view the page

browseURL(map)

map <- "../inst/doc/map3.html"
capture.output(page, file = map)
knitr::include_url(basename(map), height = "1000px")

trosendal/svis documentation built on Jan. 28, 2023, 12:05 a.m.