R | ECharts | regression lines on data groups

ecStat.regression.R

# draw regression lines on data groups with echarty
# see https://echarts.apache.org/en/option.html#dataset.fromDatasetIndex
# see https://echarts.apache.org/en/option.html#series-line.datasetIndex

library(echarty); library(dplyr)
linecolor <- c('blue','green','brown')    # color of regression lines

p <- iris %>% group_by(Species) %>% 
	ec.init(js = 'echarts.registerTransform(ecStat.transform.regression);')    # load ecStat
# add transformations and regression lines to preset scatter groups
for(i in 1:length(unique(iris$Species))) { 
	p$x$opts$dataset <- append(p$x$opts$dataset, 
		list(list(transform=list(type='ecStat:regression'), fromDatasetIndex=i )))
	p$x$opts$series <- append(p$x$opts$series,
		list(list(type='line', symbolSize=0.01, color=linecolor[i], datasetIndex=i+3 )))
}
p$x$opts$xAxis <- list(min=4)
p

idea from @jyjek

Switch positions of X and Y to show regression lines better.

library(echarty); library(dplyr)
linecolor <- c('blue','green','brown')    # color of regression lines

p <- iris |> relocate(Sepal.Width) |> group_by(Species) |>
  ec.init(js = 'echarts.registerTransform(ecStat.transform.regression);')    # load ecStat
# add transformations and regression lines to preset scatter groups
# see API https://echarts.apache.org/en/option.html#dataset.transform
for(i in 1:length(unique(iris$Species))) { 
  p$x$opts$dataset <- append(p$x$opts$dataset, 
                             list(list(transform=list(type='ecStat:regression'), fromDatasetIndex=i )))
  p$x$opts$series <- append(p$x$opts$series,
                            list(list(type='line', symbolSize=0.01, color=linecolor[i], datasetIndex=i+3 )))
}
p$x$opts$xAxis <- list(min=1.8, name='Sepal.Width', nameLocation='center')
p$x$opts$yAxis <- list(min=4, name='Sepal.Length')
p