使用 plotly 绘制线图时定义配色方案

Question

我有以下数据table（并不总是相同的，并且总是有不同的列数）和绘制折线图的代码：

dt <- data.table(date = seq(as.Date('2020-01-01'), by = '1 day', length.out = 365),
                 Germany = rnorm(365, 2, 1), Austria = rnorm(365, 3, 4), 
                 Czechia = rnorm(365, 2, 3), check.names = FALSE)

colNames <- names(dt)[-1]           ## assuming date is the first column
p <- plotly::plot_ly()

for(trace in colNames){
  p <- p %>% plotly::add_trace(data = dt, x = ~date, y = as.formula(paste0("~`", trace, "`")), name = trace,
                               type = 'scatter', mode = 'lines', connectgaps = TRUE, 
                               hovertemplate = paste("%{xaxis.title.text}:  %{x}<br>",
                                                     "%{yaxis.title.text}:  %{y}<br>") )
}

p %>% 
  layout(title = "Coal",
         xaxis = list(title = "Date"),
         yaxis = list (title = "\u20ac/MWh"))

这会产生以下图：

我想在不同的绿色阴影中创建不同的颜色选择（最深 = "#007d3c"、"#419F44" 和最浅 = "#81C07A"）。

我该怎么做？？？

Answer 1

也许试试

colNames <- names(dt)[-1] ## assuming date is the first column
colors <- setNames(c("#007d3c", "#419F44", "#81C07A"), colNames)
line_type <- setNames(c("solid", "dot", "dash"), colNames)
p <- plotly::plot_ly()

for(trace in colNames){
  p <- 
    p %>% 
    plotly::add_trace(
      data = dt, x = ~date, y = as.formula(paste0("~`", trace, "`")), name = trace,
      type = 'scatter', mode = 'lines', connectgaps = TRUE, 
      hovertemplate = paste("%{xaxis.title.text}:  %{x}<br>",
                            "%{yaxis.title.text}:  %{y}<br>"), 
      line = list(color = colors[[trace]], dash = line_type[[trace]])
    )
}


p %>% 
  layout(
    title = "Coal",
    xaxis = list(title = "Date"),
    yaxis = list (title = "\u20ac/MWh")
  )

输出图表如下所示

根据@ismirsehregal 的 post

更正了 line_type 向量

Answer 2

没有线型line我猜你想要solid:

Valid linetypes include: 'solid', 'dot', 'dash', 'longdash', 'dashdot', 'longdashdot'

以下避免使用 plot_ly 的 color/colors 和 linetype/linetypes 参数重复调用 add_trace（for 循环）：

library(plotly)
library(data.table)

DT <- data.table(date = seq(as.Date('2020-01-01'), by = '1 day', length.out = 365),
                 Germany = rnorm(365, 2, 1), Austria = rnorm(365, 3, 4), 
                 Czechia = rnorm(365, 2, 3), check.names = FALSE)

colNames <- setdiff(copy(names(DT)), "date")
colors <- setNames(c("#007d3c", "#419F44", "#81C07A"), colNames)
linetypes <- setNames(c("solid", "dot", "dash"), colNames)

DT <- melt.data.table(DT, id.vars = "date")

p <- plot_ly(DT, x = ~ date, y = ~ value, color = ~ variable, colors = colors, type = 'scatter', mode = 'lines', linetype = ~ variable, linetypes = linetypes,
             connectgaps = TRUE, name = DT[, 2],
             hovertemplate = paste("%{xaxis.title.text}:  %{x}<br>",
                                   "%{y} \u20ac/MWh <br>")) %>%
  layout(title = "<b>Coal", xaxis = list(title = "Date"), 
         yaxis = list(title = "EUR/MWh"), showlegend = FALSE)

p

请参阅 this。

使用 plotly 绘制线图时定义配色方案

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