在图例中操作“缺失”标签：tmap

Question

我希望能够操作图例中的“缺失”标签。

我在使用R中的tmap函数。我希望将其更改为“缺失或不符合升级条件”。

我尝试使用tm_text函数并考虑如何更改底层数据中的标签，但没有找到解决方案。此外，请注意代码使用映射功能。

########################
# categorical mapping function 
########################

cat.maps.wide.function <- function(data, varname, ltitle, colorplaette){
  tm_shape(data, unit = "mi") +
    tm_polygons(col = varname , # add variable(s)
                style = "cat", # set break pattern to object LQ.cuts
                palette = colorplaette,  # set color fill to blue refreshing
                border.col = "grey40", # color the borders white
                border.alpha = 0.5, # set border transparency
                title = ltitle, # title for legend
                colorNA = "white") + # color of missing data
    tm_style("bw") +
    tm_layout(panel.label.bg.color ="NA", 
              frame = FALSE, 
              bg.color = "transparent") + # panel label color
    tm_legend(legend.title.fontface = 2,  # legend bold
              legend.title.size = 0.75, 
              legend.text.size = 0.65, 
              legend.bg.alpha = 0, 
              legend.width = 5) + 
    tm_scale_bar(color.dark = "gray60", # Customize scale bar and north arrow
                 position = c(0.6, 0.05)) +  # set position of the scale bar
    tm_compass(type = "4star", 
               size = 2.5, # set size of the compass
               fontsize = 0.5, # set font size of the compass
               color.dark = "gray60", # color the compass
               text.color = "gray60", # color the text of the compass
               position = c(0.5, 0.05)) +  # set position of the compass

    # add border names
    tm_shape(boro.boundaries) + 
    tm_borders(alpha = .5) + 
    tm_text("boro", 
            size = 0.75, 
            remove.overlap = TRUE, 
            auto.placement=FALSE, 
            xmod= "x", ymod= "y") 

}

########################
# change in residential housing price
########################

# object for 2016 variable                                                 
mt1pva5.2016 <- cat.maps.wide.function(
  data = data.map.tract.wide,
  varname = "chgpcmt1pva5_overlap2016", 
  colorplaette = mt1pva5.overlap.colors, 
  ltitle = "Change in residential housing price for eligible tracts ")

mt1pva5.2016

- kaseyzapatka

---

@Ben 这是我正在处理的链接。如果你能解决这个问题，请告诉我。我曾经认为是因为表格被后来的命令覆盖了，但事实并非如此。 - kaseyzapatka

Answer 1

感谢分享数据。显然，你可以在tm_polygons中使用labels，但不能用于更改NA值。为此，你还需要使用textNA：

tm_polygons(col = varname , # add variable(s)
                style = "cat", # set break pattern to object LQ.cuts
                palette = colorplaette,  # set color fill to blue refreshing
                border.col = "grey40", # color the borders white
                border.alpha = 0.5, # set border transparency
                title = ltitle, # title for legend
                colorNA = "white", # color of missing data
                textNA = "Missing or not eligible to gentrify",
                labels = c("Decrease in residential housing price", 
                           "Increase in residential housing price")) +
...

- Ben

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谢谢Ben。这个完美地解决了问题。我不确定我是否会注意到使用textNA的微妙差别。 - kaseyzapatka

Answer 2

tm_layout() 函数有 labels 参数，它允许您通过传递字符向量来操作图例的标签。在您的 tm_layout 中添加类似以下内容：

tm_layout(labels = c("Decrease in residential housing price", 
                     "Increase in residential housing price", 
                     "Missing or not eligible to gentrify")

- Orlando Sabogal

---

谢谢您的建议，但它一直提示存在未使用的函数（即labels函数）。我在文档中找不到labels函数。它一直抛出的错误是：“Error in tm_layout(legend.title.fontface = 2, legend.title.size = 0.85, : unused argument (labels = c("Decrease in residential housing price", "Increase in residential housing price", "Missing or not eligible to gentrify"))” - kaseyzapatka