Use IUCN API with R & XPath

June 28, 2012
By

(This article was first published on theBioBucket*, and kindly contributed to R-bloggers)

Thanks to a posting on R-sig-eco mailing list I learned of the IUCN-API. Here's a simple example for what can be done with it (output as pdf is HERE):














require(XML)
require(maptools)
require(jpeg)

input = "panthera-uncia"
h <- htmlParse(paste("http://api.iucnredlist.org/go/",
input, sep = ""))

distr1 <- xpathSApply(h, '//ul[@class="countries"]', xmlValue)
distr2 <- unlist(strsplit(distr1, "\n"))
distr2[distr2 == "Russian Federation"] <- "Russia"

pop <-xpathSApply(h, '//div[@id="population"]/text()[preceding-sibling::br]', xmlValue)
status <- xpathSApply(h, '//div[@id="red_list_category_code"]', xmlValue)

data(wrld_simpl)

pdf("IUCN_map.pdf", width = 10, height = 10, pointsize = 20)
par(mar = c(3, 3, 1, 1))
plot(wrld_simpl, col = "grey98", xlim=c(-170, 170), axes = T)
plot(wrld_simpl[wrld_simpl$NAME %in% distr2,], col = "grey75", add = T)
text(0, 150, gsub("-", " ", toupper(input)), font = 3)
text(0, 130, paste("--Status: ", status, "--", sep = ""))
text(0, -98, "--Population--", cex = 0.5, font = 2)
text(0, -140, paste(strwrap(pop, width = 30), collapse = "\n"), cex = 0.4)

# download image:
myjpg <- paste(tempdir(), "/", input, ".jpg", sep = "")
download.file("http://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/Uncia_uncia.jpg/399px-Uncia_uncia.jpg",
myjpg, mode = "wb")

# read and plot image:
img <- readJPEG(myjpg)
w <- dim(img)[2]/7
h <- dim(img)[1]/7

# print img to plot region:
rasterImage(img, 115, 95, 115+w, 95+h)

graphics.off()
ps: Check THESE nice maps, too!

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