R | ECharts | heatmap and scatter with visualMap coloring

visualMap.R

library(echarty)
library(dplyr)

# 1. --------------- ECharts heatmap with categorical data, like ggplot2::geom_tile
v <- LETTERS[1:10]
set.seed(2021)
matrix <- data.frame(
  x = sample(v, 300, replace = TRUE),
  y = sample(v, 300, replace = TRUE),
  z = sample(LETTERS[1:3], 300, replace = TRUE),
  stringsAsFactors = FALSE
) %>%
  group_by(x, y) %>%
  summarise(z = z) %>%   #slice_tail() %>%
  ungroup() %>%
  mutate(z = case_when(z=='A' ~1, z=='B' ~2, TRUE ~3))

p <- matrix %>% ec.init()
p$x$opts$series <- list(list(type='heatmap'))
p$x$opts$xAxis <- list(type='category')
p$x$opts$yAxis <- list(type='category')
p$x$opts$grid <- list(show=TRUE, backgroundColor='linen')
p$x$opts$visualMap <- list(
  type='piecewise', top='top', left='center', orient='horizontal',
  pieces = list(list(value=1,label='A',color='blue'),
                list(value=2,label='B',color='red'),
                list(value=3,label='C',color='chartreuse')) )
p


# 2. --------------- scatter coloring with visualMap
set.seed(2021)
matrix <- tibble(
	x = 1:10,
	y = rnorm(10, 50 + 2 * x, 10),
	z = factor(sample(LETTERS[1:4], 10, TRUE), levels = LETTERS[1:4])
)

p <- matrix %>% ec.init()
p$x$opts$series <- list(list(type='scatter', symbolSize=12))
p$x$opts$visualMap <- list(
	top='top', left='center', orient='horizontal',
      # dimension = 2,  # z is 3rd column, 3-1=2 for JS
	dimension = 'z',  # more readable
      # categories = list('A','B','C','D'),
	categories = sort(unique(matrix$z)),  # more convenient
	inRange = list(color=list('red', 'blue', 'yellow','green'))
)
p

# RE: https://github.com/JohnCoene/echarts4r/issues/318
# RE: https://github.com/JohnCoene/echarts4r/issues/345

experiment ideas by @szmsu2011.

1. output
   

2. output
   

Simplest visualMap code, for @stla

library(echarty)
data.frame(
  x = rnorm(30), 
  y = rnorm(30), 
  year = rep(2000:2014, 2)
) |> 
ec.init(
	series.param= list(symbolSize= 10),
	visualMap= list(dimension= 3, calculable= T,
		        inRange= list(color = c("#8DD3C7", "#FFFFB3", "#BEBADA", "#FB8072")))
) 

if you like this solution, please consider granting a Github star ⭐ to echarty.