使用 tmap 和 sf 循环记录一系列地图

Question

我想使用 R 中的 sf 和 tmap 包记录一系列地图。我的数据是一个 sf 对象，具有链接到方形多边形的不同属性。对于我想要映射的每个属性，映射的中断点都是相同的，这就是为什么我想到编写一个简单的循环。

下面的代码将为您提供我的数据样本。 sorry，dput有点长，因为sf objects整合了geometry

library(sf)
library(tmap)
library(tmaptools)

Mesh <- structure(list(C1_shr_0304 = c(10.5263157894737, 9.30232558139535, 
5.63380281690141, 10.4972375690608, 8.98876404494382, 5.51181102362205, 
8.51063829787234, 8.15217391304348, 12.6168224299065), C2_shr_0304 = c(2.10526315789474, 
3.48837209302326, 1.40845070422535, 0.552486187845304, 1.68539325842697, 
1.5748031496063, 3.19148936170213, 1.08695652173913, 2.33644859813084
), C3_shr_0304 = c(14.7368421052632, 15.1162790697674, 16.9014084507042, 
9.39226519337017, 10.1123595505618, 11.8110236220472, 8.51063829787234, 
15.2173913043478, 12.1495327102804), geom = structure(list(structure(list(
    list(structure(c(544950.2102893, 544663.90075037, 544662.782562812, 
    544949.084933334, 544950.2102893, 3836419.17735834, 3836417.78717694, 
    3836648.81133503, 3836650.2015547, 3836419.17735834), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(545236.519875821, 544950.2102893, 544949.084933334, 
    545235.387351436, 545236.519875821, 3836420.57642335, 3836419.17735834, 
    3836650.2015547, 3836651.60065824, 3836420.57642335), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(545522.829510243, 545236.519875821, 545235.387351436, 
    545521.689817429, 545522.829510243, 3836421.984372, 3836420.57642335, 
    3836651.60065824, 3836653.00864566, 3836421.984372), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(544949.084933334, 544662.782562812, 544661.664316089, 
    544947.959517824, 544949.084933334, 3836650.2015547, 3836648.81133503, 
    3836879.83557164, 3836881.22582958, 3836650.2015547), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(545235.387351436, 544949.084933334, 544947.959517824, 
    545234.254767129, 545235.387351436, 3836651.60065824, 3836650.2015547, 
    3836881.22582958, 3836882.62497164, 3836651.60065824), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(544947.959517824, 544661.664316089, 544660.546010205, 
    544946.834042773, 544947.959517824, 3836881.22582958, 3836879.83557164, 
    3837110.85988679, 3837112.25018299, 3836881.22582958), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(545234.254767129, 544947.959517824, 544946.834042773, 
    545233.122122902, 545234.254767129, 3836882.62497164, 3836881.22582958, 
    3837112.25018299, 3837113.64936355, 3836882.62497164), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(545521.689817429, 545235.387351436, 545234.254767129, 
    545520.550064315, 545521.689817429, 3836653.00864566, 3836651.60065824, 
    3836882.62497164, 3836884.03299782, 3836653.00864566), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg")), structure(list(
    list(structure(c(545520.550064315, 545234.254767129, 545233.122122902, 
    545519.4102509, 545520.550064315, 3836884.03299782, 3836882.62497164, 
    3837113.64936355, 3837115.05742848, 3836884.03299782), .Dim = c(5L, 
    2L)))), class = c("XY", "MULTIPOLYGON", "sfg"))), n_empty = 0L, crs = structure(list(
    epsg = 6690L, proj4string = "+proj=utm +zone=53 +ellps=GRS80 +units=m +no_defs"), class = "crs"), class = c("sfc_MULTIPOLYGON", 
"sfc"), precision = 0, bbox = structure(c(xmin = 544660.546010205, 
ymin = 3836417.78717694, xmax = 545522.829510243, ymax = 3837115.05742848
), class = "bbox"))), row.names = c(NA, -9L), class = c("sf", 
"data.frame"), sf_column = "geom", agr = structure(c(C1_shr_0304 = NA_integer_, 
C2_shr_0304 = NA_integer_, C3_shr_0304 = NA_integer_), class = "factor", .Label = c("constant", 
"aggregate", "identity")))

要使用 tmap 制作地图，我在第一列使用以下代码：

tm_shape(Mesh) + 
  tm_fill(col = paste0(colnames(Mesh)[1]), breaks = c(0,2.5,5,7.5,10,100),
          palette= "-magma")

这给了我我想要的

示例数据中有三列。所以我写了这个简单的循环来使用相同的中断为每一列做一系列映射。

for (i in 1:3){
  png(filename = paste0(colnames(Mesh)[i],".png"), width = 480, height = 480)
  tm_shape(Mesh) + 
  tm_fill(col = paste0(colnames(Mesh)[i]), breaks = c(0,2.5,5,7.5,10,100),
          palette= "-magma")
  dev.off()
}

这个循环不起作用，我的文件夹中的文件已创建但为空。另外，将所有三张地图都放在一个文件中可能会更好，但我想先解决这个问题。非常感谢任何帮助。

Answer 1

您只需要运行以下代码行，它应该可以工作。

library(tmap)

for (i in 1:3){

  res <- tm_shape(Mesh) + 
    tm_fill(col = paste0(colnames(Mesh)[i]), breaks = c(0,2.5,5,7.5,10,100),
            palette= "-magma")
  
  tmap_save(res, filename = paste0(colnames(Mesh)[i], ".png", sep = ""))

}

^{由 reprex package (v2.0.1)}

创建于 2021-09-21

Answer 2

只需在循环中使用 print(m)。

如果您想使用基本图形设备，您需要显式打印您的 tmap。否则，请像其他答案一样使用 tmap_save()。

for(i in 1:3){
  png(filename = paste0(colnames(Mesh)[i],".png"), width = 480, height = 480)
  m <- tm_shape(Mesh) + 
    tm_fill(col = paste0(colnames(Mesh)[i]),
            breaks = c(0,2.5,5,7.5,10,100),
            palette= "-magma")
  print(m)
  dev.off()
}

why is tmap function within for loop that also has left join not working

使用 tmap 和 sf 循环记录一系列地图

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