在Plotly R中为条形图添加注释。

Question

我需要在2019年和2020年的图表中添加注释。我有一个问题，要到2020年。我想按下图所示做，但文字与2019年的文字重叠。

quarter <- c("Q1", "Q2", "Q3")
y_18 <- c(10, 16, 23)
y_19 <- c(12, 20, 29)
y_20 <- c(14, NA, NA)
TD <- data.frame(quarter, y_18, y_19, y_20)

fig <- plot_ly(TD, x = ~quarter, y = ~y_18, type = 'bar', name = '2018')
fig <- fig %>% add_trace(y = ~y_19, name = '2019')
fig <- fig %>% add_trace(y = ~y_20, name = '2020')
fig <- fig %>% layout(yaxis = list(title = 'count'), barmode = 'group')
fig <- fig %>% add_annotations( x = TD$quarter,
                                y = TD$y_19,
                                text = c("+2","+4","+6"),
                                xref = "x",
                                yref = "y",
                                showarrow = TRUE)

#my solutions:
fig <- fig %>% add_annotations( x = TD[1,1],
                                y = TD[1,3],
                                text = "+2",
                                xref = "x",
                                yref = "y",
                                showarrow = TRUE)

Answer 1

只要稍加人工干预，就能找出合适的y坐标（见下图）.我把3个坐标都留了下来，如果你想用na标注的，只需在代码中替换空白注释和showarrow的false逻辑即可。

library(plotly)
quarter <- c("Q1", "Q2", "Q3")
y_18 <- c(10, 16, 23)
y_19 <- c(12, 20, 29)
y_20 <- c(14, NA, NA)
TD <- data.frame(quarter, y_18, y_19, y_20)

fig <- plot_ly(TD, x = ~quarter, y = ~y_18, type = 'bar', name = '2018')
fig <- fig %>% add_trace(y = ~y_19, name = '2019')
fig <- fig %>% add_trace(y = ~y_20, name = '2020')
fig <- fig %>% layout(yaxis = list(title = 'count'), barmode = 'group')
fig <- fig %>% add_annotations( x = TD$quarter,
                                y = TD$y_19,
                                text = c("+2","+4","+6"),
                                xref = "x",
                                yref = "y",
                                showarrow = TRUE)

fig %>% add_annotations( x = c(.25, 1.25, 2.25),
                         y = TD$y_20,
                         text = c("+2","",""),
                         xref = "x",
                         yref = "y",
                         showarrow = c(TRUE, FALSE, FALSE))