2022/05/choropleth-map-animation/

[utterances-bot]

动态地区分布图 - Xiangyun Huang

https://xiangyun.rbind.io/2022/05/choropleth-map-animation/

[XiangyunHuang]

在自定义坐标投影方面， @helgasoft 基于 Apache Echarts 的 demo 用 echarty 包实现代码。

[helgasoft]

Great article!
Here is Figure 11 made with library echarty.

library(maps)
votes_repub <- as.data.frame(votes.repub)
votes_repub = within(votes_repub, {
	state_name = rownames(votes_repub)
	state = tolower(rownames(votes_repub)) # 州名转小写
})
us_votes_repub <- reshape(
	data = votes_repub,
	# 需要转行的列，列名构成的向量
	varying = as.character(seq(1856, 1976, by = 4)),
	times = as.character(seq(1856, 1976, by = 4)), # 构成新列 year 的列值
	v.names = "repub_prop", # 列转行 列值构成的新列，指定名称
	timevar = "year", # 列转行 列名构成的新列，指定名称
	idvar = "state", # 州名
	new.row.names = 1:(31 * 50),
	direction = "long"
)
mapurl <- "https://fastly.jsdelivr.net/gh/apache/echarts-website@asf-site/examples/data/asset/geo/USA.json"
usaJson <- jsonlite::read_json(mapurl)


library(echarty)
p <- us_votes_repub |>  # subset(subset= year>"1970") |>
	group_by(year) |>
	ec.init(js= 'projection = d3.geoAlbersUsa();',
		  tl.series= list(
			type= 'map',
			encode= list(name='state_name', value='repub_prop')
		  	)
	) |>
	ec.plugjs('https://fastly.jsdelivr.net/npm/d3-array') |> 
	ec.plugjs('https://fastly.jsdelivr.net/npm/d3-geo')
p$x$registerMap <- list(list(mapName='USA', geoJSON= usaJson))
p$x$opts$geo <- list(map= 'USA', roam= TRUE,
		projection= list(
			project=   htmlwidgets::JS('function(point) {return projection(point);}'),
			unproject= htmlwidgets::JS('function(point) {return projection.invert(point);}')
							)
)
p$x$opts$xAxis <- p$x$opts$yAxis <- NULL    # delete redundant presets
p$x$opts$options <- lapply(p$x$opts$options, function(op) {
	# update preset titles
	op$title$right <- 100; op$title$top <- 50
	op$title$textStyle <- list(
		fontSize = 100,
		color = "rgb(170, 170, 170, 0.5)",
		fontWeight = "bolder"
	)
	# add 'permanent' top title to all options
	op$title <- list(op$title, list(
		text= "1856-1976 年美国历届大选中共和党在各州的得票率", 
		subtext= "数据源：maps 包内置数据集 votes.repub",
		sublink= "https://cran.r-project.org/package=maps/",
		left= "center"))
	op
})
p$x$opts$visualMap <- list(left= 'right', 
	 min= min(us_votes_repub$repub_prop, na.rm=T), 
	 max= max(us_votes_repub$repub_prop, na.rm=T), 
	 inRange= list(color= RColorBrewer::brewer.pal(n= 11, name = "RdBu")),
	 text = c("高", "低"), calculable= TRUE)
p$x$opts$tooltip <- list(show=TRUE)
p$x$opts$timeline <- append(p$x$opts$timeline, list(autoPlay=TRUE, bottom=20))   # update preset
p
# p |> ec.inspect()   # inspect JS code generated

[XiangyunHuang]

@helgasoft echarty is great, Thank you!

[XiangyunHuang]

Here is output made by @helgasoft

echarty.mov

[XiangyunHuang]

目前，R 包 echarts4r 正式发布的版本 0.4.3 支持到 Apache Echarts 5.2.2，而 给 e_map 加坐标投影特性，需要 echarts4r 将内置的 JS 库 Apache Echarts 升级到至少 5.3.0， 详见Apache Echarts 官方网站。

[XiangyunHuang]

截止 2022-05-28 北京时间下午 6点：echarts4r 包内置的 JS 库 Apache Echarts 升级到 5.3.2，R 包现已更新至 0.4.4 版本，已正式发布在 CRAN 上了，复现文章中的图 12，不需要从 Github 上安装开发版了。