Streamgraph NAREIT Growth

gistfile1.r

library(rvest); library(dplyr); library(tidyr);library(streamgraph); library(magrittr)
url <- #where does the data live
	"https://www.reit.com/investing/industry-data-research/us-reit-industry-equity-market-cap"

reits_raw <- #scrape it
	url %>%
	html %>%
	html_table(header = F) %>%
	data.frame

names(reits_raw) <- #name it
	c('year','companies_all.reits','marketcap_all.reits'
		,'companies_equity.reits', 'marketcap_equity.reits'
		,'companies_mortgage.reits', 'marketcap_mortgage.reits'
		,'companies_hybrid.reits', 'marketcap_hybrid.reits')

reits <- #discard what we dont need
	reits_raw[5:nrow(reits_raw),]

reits %<>% #convert to numbers
	apply(2, function(x) extract_numeric(x)) %>% data.frame %>% tbl_df

reits_api_friendly <- #go from wide to long
	reits %>%
	gather(item, value, -year)

reits_api_friendly %<>% #split dual named columns
	separate(item,c('aggregator','reit_type'), "_")

dat <-  #filter the data for the plot -- exclude all
	reits_api_friendly %>% 
	filter(aggregator %in% 'marketcap') %>% 
	filter(!reit_type == 'all.reits') 

dat$year %<>% #datify it
	paste0("12-31-",.) %>% as.Date("%m-%d-%Y")

dat %>%  #plot it
	streamgraph("reit_type", "value", "year",offset="silhouette", #what type of graph
						interactive=TRUE) %>%
	sg_axis_x(4, "year", "%Y") %>% #year increments
	sg_axis_y(12, tick_format = "$4,d.0") %>% #y axis increments
	sg_fill_brewer("Spectral") %>%
	sg_legend(TRUE, "REIT Type: ")