使用 qmplot 叠加图例

Question

我有以下代码可以创建正确着色的地图叠加层。唯一的问题是我无法让它包含正确的图例。我想要做的是添加 2 个图例，每个标度/候选图例一个 - 这样就会有一个蓝色图例显示可能的间隔，一个红色图例显示所有可能的间隔。间隔由中断定义，其中每个整数是间隔的底部和下一个间隔的顶部（间隔：40-50、50-60、60-70、70-80、80-90）。我的代码似乎很接近，但它切断了红色的顶部间隔，而且它似乎在反转颜色。

这是在没有图例的情况下生成正确地图着色的代码：

library(httr)
library(XML)
library(ggplot2)
library(maps)
library(RColorBrewer)
library(maptools)
library(ggmap)

# Map data for Alabama counties (polygons)
ala <- map("county", regions = "alabama", plot = FALSE, fill = TRUE)
sapply(ala, head)

IDs <- sub("^alabama,", "", ala$names)
head(IDs)

ala_sp <- map2SpatialPolygons(ala, IDs, CRS("+proj=longlat"))
names(ala_sp)
slotNames(ala_sp)
bbox(ala_sp)

plot(ala_sp, axes = TRUE)


# ggmap version of overlay
ala_data <- fortify(ala_sp)
dim(ala_data)
ala_data[1:60, ]
subset(ala_data, id == "st clair") # need to match saint clair
ala_data$id <- gsub("st clair", "saint clair", ala_data$id)
subset(ala_data, id == "saint clair") # check matches
head(ala_data)

# Define the breaks
breaks <- c(40, 50, 60, 70, 80, 90)

# Define the colors
colors <- brewer.pal(10, "RdBu")
jones_colors <- colors[6:10]
moore_colors <- colors[5:1]

# Assign colors
jones_cuts <- cut(etable$JonesPct, breaks)
moore_cuts <- cut(etable$MoorePct, breaks)
jones <- jones_colors[jones_cuts]
moore <- moore_colors[moore_cuts]
map_colors <- ifelse(is.na(etable$JonesPct), moore, jones)

# Create matching data and merge
vote_data <- cbind(etable, map_colors)
vote_data$County <- tolower(vote_data$County)
vote_data$County <- gsub("st. clair", "saint clair", vote_data$County)
vote_data$County <- gsub("dekalb", "de kalb", vote_data$County)
vote_data <- vote_data[order(vote_data$County), ]
head(vote_data)

ala_color_data <- merge(ala_data, vote_data[c("County", "map_colors")], 
                        by.x = "id", by.y = "County", all.x = TRUE)
ala_color_data <- ala_color_data[order(ala_color_data$id), ]

#### Colored map without legend, correct colors ####
qmplot(long, lat, data = ala_data, force = TRUE, legend = "bottomright", alpha = I(0)) +
  geom_polygon(aes(x = long, y = lat, group = group, fill = map_colors),
               data = ala_color_data,
               colour = "white", alpha = 0.4, size = 0.3
  ) +
  scale_fill_identity() +
  labs(title = "Alabama Election Results 2017 - U.S. Senate",
       subtitle = "\n Moore vs. Jones") +
  theme(plot.title = element_text(hjust = 0.5),
        plot.subtitle = element_text(hjust = 0.5, color = "gray40")) 

这使用以下数据：

> dput(vote_data)
structure(list(County = c("autauga", "baldwin", "barbour", "bibb", 
"blount", "bullock", "butler", "calhoun", "chambers", "cherokee", 
"chilton", "choctaw", "clarke", "clay", "cleburne", "coffee", 
"colbert", "conecuh", "coosa", "covington", "crenshaw", "cullman", 
"dale", "dallas", "de kalb", "elmore", "escambia", "etowah", 
"fayette", "franklin", "geneva", "greene", "hale", "henry", "houston", 
"jackson", "jefferson", "lamar", "lauderdale", "lawrence", "lee", 
"limestone", "lowndes", "macon", "madison", "marengo", "marion", 
"marshall", "mobile", "monroe", "montgomery", "morgan", "perry", 
"pickens", "pike", "randolph", "russell", "saint clair", "shelby", 
"sumter", "talladega", "tallapoosa", "tuscaloosa", "walker", 
"washington", "wilcox", "winston"), Jones = c(5606, 22131, 3680, 
1567, 2405, 2712, 2914, 11705, 4247, 1525, 2298, 2273, 4346, 
985, 594, 3715, 6865, 2259, 1414, 2102, 1320, 4156, 3842, 10492, 
3559, 7711, 3640, 10518, 1142, 1770, 1289, 3340, 3894, 1896, 
9107, 3328, 149522, 779, 9908, 3028, 19810, 9606, 3779, 5780, 
65664, 4495, 1311, 5134, 62253, 3244, 48186, 10901, 3138, 3057, 
3989, 1692, 6761, 6203, 27251, 3527, 9967, 4590, 30858, 4317, 
1799, 3344, 911), Moore = c(8752, 38445, 2699, 3599, 11621, 656, 
2756, 14567, 3308, 3996, 7555, 1949, 3984, 2586, 2465, 8052, 
7762, 1815, 1867, 6825, 2347, 16602, 6988, 3485, 10097, 14411, 
4985, 15693, 3491, 4214, 5431, 462, 1691, 3014, 14796, 7316, 
66309, 2847, 12775, 5314, 14017, 14298, 988, 758, 46313, 2804, 
5268, 13828, 46725, 3276, 17705, 19187, 821, 2961, 4154, 3229, 
3622, 15876, 36424, 814, 9698, 7171, 22064, 11909, 3320, 999, 
4680), WriteIns = c(253, 1699, 41, 66, 180, 7, 41, 399, 75, 110, 
132, 17, 43, 44, 30, 202, 171, 18, 30, 88, 56, 324, 136, 60, 
234, 338, 87, 617, 50, 48, 93, 9, 32, 38, 285, 154, 3710, 29, 
382, 61, 672, 515, 13, 20, 3446, 62, 68, 449, 1539, 40, 743, 
668, 11, 46, 97, 23, 55, 459, 1718, 18, 223, 148, 1007, 259, 
48, 16, 67), Rpt = c("100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%"), Total = c(14611, 
62275, 6420, 5232, 14206, 3375, 5711, 26671, 7630, 5631, 9985, 
4239, 8373, 3615, 3089, 11969, 14798, 4092, 3311, 9015, 3723, 
21082, 10966, 14037, 13890, 22460, 8712, 26828, 4683, 6032, 6813, 
3811, 5617, 4948, 24188, 10798, 219541, 3655, 23065, 8403, 34499, 
24419, 4780, 6558, 115423, 7361, 6647, 19411, 110517, 6560, 66634, 
30756, 3970, 6064, 8240, 4944, 10438, 22538, 65393, 4359, 19888, 
11909, 53929, 16485, 5167, 4359, 5658), JonesPct = c(NA, NA, 
57.3208722741433, NA, NA, 80.3555555555556, 51.0243389949221, 
NA, 55.6618610747051, NA, NA, 53.6211370606275, 51.9049325211991, 
NA, NA, NA, NA, 55.2052785923754, NA, NA, NA, NA, NA, 74.7453159507017, 
NA, NA, NA, NA, NA, NA, NA, 87.6410390973498, 69.3252625956917, 
NA, NA, NA, 68.1066406730406, NA, NA, NA, 57.4219542595438, NA, 
79.0585774058577, 88.1366270204331, 56.8898746350381, 61.0650726803423, 
NA, NA, 56.3288905779201, NA, 72.3144340726956, NA, 79.0428211586902, 
50.4122691292876, NA, NA, 64.7729450086223, NA, NA, 80.9130534526268, 
50.1156476267096, NA, 57.2196777244154, NA, NA, 76.7148428538656, 
NA), MoorePct = c(59.9000752857436, 61.7342432757929, NA, 68.7882262996942, 
81.8034633253555, NA, NA, 54.6173746766151, NA, 70.964304741609, 
75.6634952428643, NA, NA, 71.5352697095436, 79.799287795403, 
67.2737906257833, 52.45303419381, NA, 56.3877982482634, 75.7071547420965, 
63.0405586892291, 78.7496442462764, 63.7242385555353, NA, 72.6925845932325, 
64.1629563668744, 57.2199265381084, 58.4948561204711, 74.5462310484732, 
69.8607427055703, 79.7152502568619, NA, NA, 60.9135004042037, 
61.170828510005, 67.7532876458604, NA, 77.8932968536252, 55.3869499241275, 
63.2393192907295, NA, 58.5527662885458, NA, NA, NA, NA, 79.2537987061832, 
71.237957858946, NA, 49.9390243902439, NA, 62.384575367408, NA, 
NA, 50.4126213592233, 65.3114886731392, NA, 70.4410329221759, 
55.7001513923509, NA, NA, 60.2149634730036, NA, 72.2414316044889, 
64.2539191019934, NA, 82.7147401908802), map_colors = c("#F4A582", 
"#D6604D", "#92C5DE", "#D6604D", "#67001F", "#053061", "#92C5DE", 
"#F4A582", "#92C5DE", "#B2182B", "#B2182B", "#92C5DE", "#92C5DE", 
"#B2182B", "#B2182B", "#D6604D", "#F4A582", "#92C5DE", "#F4A582", 
"#B2182B", "#D6604D", "#B2182B", "#D6604D", "#2166AC", "#B2182B", 
"#D6604D", "#F4A582", "#F4A582", "#B2182B", "#D6604D", "#B2182B", 
"#053061", "#4393C3", "#D6604D", "#D6604D", "#D6604D", "#4393C3", 
"#B2182B", "#F4A582", "#D6604D", "#92C5DE", "#F4A582", "#2166AC", 
"#053061", "#92C5DE", "#4393C3", "#B2182B", "#B2182B", "#92C5DE", 
"#FDDBC7", "#2166AC", "#D6604D", "#2166AC", "#92C5DE", "#F4A582", 
"#D6604D", "#4393C3", "#B2182B", "#F4A582", "#053061", "#92C5DE", 
"#D6604D", "#92C5DE", "#B2182B", "#D6604D", "#2166AC", "#67001F"
)), row.names = c(22L, 6L, 43L, 50L, 23L, 65L, 46L, 11L, 37L, 
48L, 31L, 58L, 35L, 64L, 67L, 26L, 21L, 59L, 66L, 32L, 62L, 17L, 
28L, 24L, 25L, 16L, 33L, 10L, 55L, 45L, 39L, 61L, 49L, 52L, 13L, 
29L, 1L, 63L, 14L, 34L, 8L, 12L, 54L, 42L, 2L, 38L, 40L, 19L, 
3L, 41L, 4L, 9L, 60L, 44L, 36L, 53L, 30L, 15L, 5L, 56L, 18L, 
27L, 7L, 20L, 51L, 57L, 47L), class = "data.frame")

和

> dput(etable)
structure(list(County = c("Jefferson", "Madison", "Mobile", "Montgomery", 
"Shelby", "Baldwin", "Tuscaloosa", "Lee", "Morgan", "Etowah", 
"Calhoun", "Limestone", "Houston", "Lauderdale", "St. Clair", 
"Elmore", "Cullman", "Talladega", "Marshall", "Walker", "Colbert", 
"Autauga", "Blount", "Dallas", "DeKalb", "Coffee", "Tallapoosa", 
"Dale", "Jackson", "Russell", "Chilton", "Covington", "Escambia", 
"Lawrence", "Clarke", "Pike", "Chambers", "Marengo", "Geneva", 
"Marion", "Monroe", "Macon", "Barbour", "Pickens", "Franklin", 
"Butler", "Winston", "Cherokee", "Hale", "Bibb", "Washington", 
"Henry", "Randolph", "Lowndes", "Fayette", "Sumter", "Wilcox", 
"Choctaw", "Conecuh", "Perry", "Greene", "Crenshaw", "Lamar", 
"Clay", "Bullock", "Coosa", "Cleburne"), Jones = c(149522, 65664, 
62253, 48186, 27251, 22131, 30858, 19810, 10901, 10518, 11705, 
9606, 9107, 9908, 6203, 7711, 4156, 9967, 5134, 4317, 6865, 5606, 
2405, 10492, 3559, 3715, 4590, 3842, 3328, 6761, 2298, 2102, 
3640, 3028, 4346, 3989, 4247, 4495, 1289, 1311, 3244, 5780, 3680, 
3057, 1770, 2914, 911, 1525, 3894, 1567, 1799, 1896, 1692, 3779, 
1142, 3527, 3344, 2273, 2259, 3138, 3340, 1320, 779, 985, 2712, 
1414, 594), Moore = c(66309, 46313, 46725, 17705, 36424, 38445, 
22064, 14017, 19187, 15693, 14567, 14298, 14796, 12775, 15876, 
14411, 16602, 9698, 13828, 11909, 7762, 8752, 11621, 3485, 10097, 
8052, 7171, 6988, 7316, 3622, 7555, 6825, 4985, 5314, 3984, 4154, 
3308, 2804, 5431, 5268, 3276, 758, 2699, 2961, 4214, 2756, 4680, 
3996, 1691, 3599, 3320, 3014, 3229, 988, 3491, 814, 999, 1949, 
1815, 821, 462, 2347, 2847, 2586, 656, 1867, 2465), WriteIns = c(3710, 
3446, 1539, 743, 1718, 1699, 1007, 672, 668, 617, 399, 515, 285, 
382, 459, 338, 324, 223, 449, 259, 171, 253, 180, 60, 234, 202, 
148, 136, 154, 55, 132, 88, 87, 61, 43, 97, 75, 62, 93, 68, 40, 
20, 41, 46, 48, 41, 67, 110, 32, 66, 48, 38, 23, 13, 50, 18, 
16, 17, 18, 11, 9, 56, 29, 44, 7, 30, 30), Rpt = c("100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%", "100%", "100%", "100%", "100%", "100%", "100%", "100%", 
"100%"), Total = c(219541, 115423, 110517, 66634, 65393, 62275, 
53929, 34499, 30756, 26828, 26671, 24419, 24188, 23065, 22538, 
22460, 21082, 19888, 19411, 16485, 14798, 14611, 14206, 14037, 
13890, 11969, 11909, 10966, 10798, 10438, 9985, 9015, 8712, 8403, 
8373, 8240, 7630, 7361, 6813, 6647, 6560, 6558, 6420, 6064, 6032, 
5711, 5658, 5631, 5617, 5232, 5167, 4948, 4944, 4780, 4683, 4359, 
4359, 4239, 4092, 3970, 3811, 3723, 3655, 3615, 3375, 3311, 3089
), JonesPct = c(68.1066406730406, 56.8898746350381, 56.3288905779201, 
72.3144340726956, NA, NA, 57.2196777244154, 57.4219542595438, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, 50.1156476267096, NA, NA, 
NA, NA, NA, 74.7453159507017, NA, NA, NA, NA, NA, 64.7729450086223, 
NA, NA, NA, NA, 51.9049325211991, NA, 55.6618610747051, 61.0650726803423, 
NA, NA, NA, 88.1366270204331, 57.3208722741433, 50.4122691292876, 
NA, 51.0243389949221, NA, NA, 69.3252625956917, NA, NA, NA, NA, 
79.0585774058577, NA, 80.9130534526268, 76.7148428538656, 53.6211370606275, 
55.2052785923754, 79.0428211586902, 87.6410390973498, NA, NA, 
NA, 80.3555555555556, NA, NA), MoorePct = c(NA, NA, NA, NA, 55.7001513923509, 
61.7342432757929, NA, NA, 62.384575367408, 58.4948561204711, 
54.6173746766151, 58.5527662885458, 61.170828510005, 55.3869499241275, 
70.4410329221759, 64.1629563668744, 78.7496442462764, NA, 71.237957858946, 
72.2414316044889, 52.45303419381, 59.9000752857436, 81.8034633253555, 
NA, 72.6925845932325, 67.2737906257833, 60.2149634730036, 63.7242385555353, 
67.7532876458604, NA, 75.6634952428643, 75.7071547420965, 57.2199265381084, 
63.2393192907295, NA, 50.4126213592233, NA, NA, 79.7152502568619, 
79.2537987061832, 49.9390243902439, NA, NA, NA, 69.8607427055703, 
NA, 82.7147401908802, 70.964304741609, NA, 68.7882262996942, 
64.2539191019934, 60.9135004042037, 65.3114886731392, NA, 74.5462310484732, 
NA, NA, NA, NA, NA, NA, 63.0405586892291, 77.8932968536252, 71.5352697095436, 
NA, 56.3877982482634, 79.799287795403)), row.names = c(NA, -67L
), class = "data.frame")
> 

它输出的颜色正确：

我试过用这种方式添加图例：

#### colored map with legend, colors are off ####

# # Create a new data frame for the legend
intervals <- c("dem 40-50", "dem 50-60", "dem 60-70", "dem 70-80", "dem 80-90",
               "rep 40-50", "rep 50-60", "rep 60-70", "rep 70-80", "rep 80-90")

# Combine the colors for both candidates
colors <- c(jones_colors, moore_colors)

# Colored map with legend
qmplot(long, lat, data = ala_data, force = TRUE, alpha = I(0)) +
  geom_polygon(aes(x = long, y = lat, group = group, fill = map_colors),
               data = ala_color_data,
               colour = "white", alpha = 0.4, size = 0.3
  ) +
  scale_fill_manual(values = colors,
                    labels = c(intervals),
                    name = "Percentages") +
  labs(title = "Alabama Election Results 2017 - U.S. Senate",
       subtitle = "\n Moore vs. Jones") +
  theme(plot.title = element_text(hjust = 0.5),
        plot.subtitle = element_text(hjust = 0.5, color = "gray40"))

但它会反转颜色并完全关闭最后的红色间隔。