living former presidents.R

x <-
	structure(list(name = c("George Washington", "John Adams", "Thomas Jefferson", 
	"James Madison", "James Monroe", "John Quincy Adams", "Andrew Jackson", 
	"Martin Van Buren", "William Henry Harrison", "John Tyler", "James K. Polk", 
	"Zachary Taylor", "Millard Fillmore", "Franklin Pierce", "James Buchanan", 
	"Abraham Lincoln", "Andrew Johnson", "Ulysses S. Grant", "Rutherford B. Hayes", 
	"James A. Garfield", "Chester Arthur", "Grover Cleveland", "Benjamin Harrison", 
	"William McKinley", "Theodore Roosevelt", "William Howard Taft", 
	"Woodrow Wilson", "Warren G. Harding", "Calvin Coolidge", "Herbert Hoover", 
	"Franklin Roosevelt", "Harry S. Truman", "Dwight Eisenhower", 
	"John F. Kennedy", "Lyndon B. Johnson", "Richard Nixon", "Gerald Ford", 
	"Jimmy Carter", "Ronald Reagan", "George Bush", "Bill Clinton", 
	"George W. Bush", "Barack Obama", "Donald Trump"), birth = structure(c(-86876, 
	-85530, -82808, -79914, -77314, -73953, -74071, -68327, -71913, 
	-65656, -63612, -67607, -62085, -60304, -65266, -58762, -58807, 
	-53940, -53780, -50447, -51222, -48501, -49807, -46358, -40608, 
	-41015, -41276, -38045, -35609, -34842, -32112, -31283, -28933, 
	-19210, -22407, -20811, -20625, -16528, -21514, -16639, -8536, 
	-8580, -3072, -8602), class = "Date"), death = structure(c(-62109, 
	-52411, -52411, -48764, -50585, -44507, -45497, -39242, -47023, 
	-39429, -44029, -43640, -34997, -36609, -37103, -38246, -34487, 
	-30842, -28107, -32245, -30359, -22471, -25131, -24946, -18623, 
	-14544, -16769, -16954, -13510, -1899, -9030, 1090, -279, -2232, 
	1117, 8877, 13508, NA, 12574, NA, NA, NA, NA, 
	NA), class = "Date"), term_start = structure(c(-65989, -63124, 
	-61664, -58742, -55820, -52898, -51437, -48515, -47054, -47023, 
	-45593, -44132, -43640, -42671, -41210, -39749, -38246, -36827, 
	-33905, -32444, -32245, -30983, -29522, -26600, -24946, -22218, 
	-20757, -17835, -16954, -14913, -13452, -9030, -6190, -3268, 
	-2232, -346, 1681, 2576, 4037, 6959, 8420, 11342, 14264, 17186
	), class = "Date"), term_end = structure(c(-63124, -61664, -58742, 
	-55820, -52898, -51437, -48515, -47054, -47023, -45593, -44132, 
	-43640, -42671, -41210, -39749, -38246, -36827, -33905, -32444, 
	-32245, -30983, -29522, -28061, -24946, -22218, -20757, -17835, 
	-16954, -14913, -13452, -9030, -6190, -3268, -2232, -346, 1681, 
	2576, 4037, 6959, 8420, 11342, 14264, 17186, NA), class = "Date")), .Names = c("name", 
	"birth", "death", "term_start", "term_end"), row.names = c(1L, 
	2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L, 
	16L, 17L, 18L, 19L, 20L, 21L, 22L, 23L, 25L, 26L, 27L, 28L, 29L, 
	30L, 31L, 32L, 33L, 34L, 35L, 36L, 37L, 38L, 39L, 40L, 41L, 42L, 
	43L, 44L, 45L), class = "data.frame")


first_term_start <- min( x$term_start )
today <- Sys.Date()
x[ is.na( x ) ] <- today + 1

y <- 
	data.frame(
		this_day = seq( first_term_start , today , "day" ) ,
		presidents_died = 
			sapply( seq( first_term_start , today , "day" ) , function( w ) sum( w >= x$death ) ) ,
		presidents_started = 
			sapply( seq( first_term_start , today , "day" ) , function( w ) sum( w >= x$term_start ) )
	)

y$living_former_presidents <- y$presidents_started - y$presidents_died - 1

plot( y$this_day , y$living_former_presidents , xlab = '' , ylab = '' , main = 'living former presidents throughout us history' , type = 'l' , bty = 'n' )