M. Beausoleil's questions

我有 2 个列表：

a = list(data.frame(a = 1:10, b = 21:30), data.frame(a = 11:20, b = 31:40))
b = list(data.frame(c = letters[1:10]), data.frame(c = LETTERS[1:10]))

我想自动对它们进行 cbind，以便 c 列与 a 列表中的每个元素配对。

这是我的期望（手动）

c = list(data.frame(a = 1:10, b = 21:30, c = letters[1:10]), data.frame(a = 11:20, b = 31:40, c = LETTERS[1:10]))

当尝试这个时，

do.call(cbind, a, b)

我明白了

Error in if (quote) args <- lapply(args, enquote) : 
  the condition has length > 1

预期输出：

c
[[1]]
    a  b c
1   1 21 a
2   2 22 b
3   3 23 c
4   4 24 d
5   5 25 e
6   6 26 f
7   7 27 g
8   8 28 h
9   9 29 i
10 10 30 j

[[2]]
    a  b c
1  11 31 A
2  12 32 B
3  13 33 C
4  14 34 D
5  15 35 E
6  16 36 F
7  17 37 G
8  18 38 H
9  19 39 I
10 20 40 J

将 sf 对象打印到控制台时，有一个带有Geodetic CRS或 的标题Porjected CRS，其中包含 CRS 的良好格式名称。有没有办法提取此信息，而不是

p1 = st_point(c(7,52))
p2 = st_point(c(-30,20))
sfc = st_sfc(p1, p2, crs = 4326)
sfc
Geometry set for 2 features 
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: -30 ymin: 20 xmax: 7 ymax: 52
Geodetic CRS:  WGS 84                  <- this line
POINT (7 52)
POINT (-30 20)

st_transform(sfc, 3857)
Geometry set for 2 features 
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: -3339585 ymin: 2273031 xmax: 779236.4 ymax: 6800125
Projected CRS: WGS 84 / Pseudo-Mercator                  <- this line
POINT (779236.4 6800125)
POINT (-3339585 2273031)

nc = st_read(system.file("shape/nc.shp", package="sf"))
nc
Simple feature collection with 100 features and 14 fields
Geometry type: MULTIPOLYGON
Dimension:     XY
Bounding box:  xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
Geodetic CRS:  NAD27                  <- this line
First 10 features:
[...]

看看如何st_crs(sfc)$input给予"EPSG:4326"而不是WGS 84。然而，st_crs(nc)$input给予"NAD27"，但st_crs(st_transform(sfc, 3857))$input给予 "EPSG:3857"而不是Projected CRS: WGS 84 / Pseudo-Mercator

地球上是否也存在与栅格数据相当的东西？

我有一个代码，其中有一个场景（sc列）和一个代码名称（cd列）。我想计算所有场景与第一个场景之间的差异（所以场景2-1，3-1等等。我还有多个场景......）。有没有一种快速的方法来编码将要比较哪个场景，例如，如果我现在所有其他场景的比较场景现在是场景 2，那将是1-2，3-2等等？

但我也想确保在场景之间只减去相同的代号名称（cd），所以（sc1.cd1 - sc2.cd1），（sc1.cd2 - sc2.cd2）等等。

sc我还想要了解每个代码中 1 与其他场景之间的百分比差异。

目前，我的代码假设当我比较场景时，它们cd的顺序相同。有没有办法将场景和代码一起比较，而不是使用数据子集？

set.seed(123456)
vals = as.vector(mapply(FUN = rpois, n = 10, lambda = c(5, 10, 100)))
df.test = data.frame(cd = rep(1:10,3), sc = rep(1:3, each =10 ), vals)

# New empty column 
df.test$delta = NA

# Subset each scenarios and subtract for the first scenario
df.test[df.test$sc ==1,'delta'] = df.test[df.test$sc ==1,'vals']-df.test[df.test$sc ==1,'vals']
df.test[df.test$sc ==2,'delta'] = df.test[df.test$sc ==2,'vals']-df.test[df.test$sc ==1,'vals']
df.test[df.test$sc ==3,'delta'] = df.test[df.test$sc ==3,'vals']-df.test[df.test$sc ==1,'vals']

# Get difference
df.test$diff = abs(abs(df.test$delta) - df.test$vals)

# Calculate percentage
df.test$delta.perc = abs(df.test$delta) / df.test$diff +1
df.test$diff * df.test$delta.perc

# Percentage increase
df.test$delta.perc.increase = df.test$delta.perc *100

我正在使用 mapview 包构建地图。但是，当我使用 st_sample 并生成点时，有些点没有被映射。另外，st_buffer合并了一些区域（它们应该是分开的）。

library(sf)
library(mapview)
library(magrittr)
set.seed(145)

chemins.32188 = st_zm(chemins2) %>% st_transform(crs = 32188)

rd.pts.sentiers <- st_sample(x = chemins.32188, size = 10)

buff.pt = st_buffer(x = rd.pts.sentiers, 
                    dist = units::set_units(x = 100, 
                                           value = "m"))
mapviewOptions(fgb = FALSE)
mapview(chemins.32188) + 
  mapview(rd.pts.sentiers) +
  mapview(buff.pt)

当我使用绘图时，它可以工作......但缓冲区仍然被合并。

plot(chemins.32188$geom) 
plot(buff.pt, add= TRUE, col = scales::alpha("blue", .5))
plot(rd.pts.sentiers, add= TRUE, pch = 19, col = "red")

这是数据

chemins2 = structure(list(Name = "Path Measure", description = NA_character_, 
               timestamp = structure(NA_real_, class = c("POSIXct", "POSIXt"
               )), begin = structure(NA_real_, class = c("POSIXct", "POSIXt"
               )), end = structure(NA_real_, class = c("POSIXct", "POSIXt"
               )), altitudeMode = NA_character_, tessellate = -1L, extrude = 0L, 
               visibility = -1L, drawOrder = NA_integer_, icon = NA_character_, 
               sentier = NA_character_, layer = "path Parc — Path Measure", 
               path = "~/Desktop/path Parc.kml|layername=Path Measure|geometrytype=LineString25D|uniqueGeometryType=yes", 
               geom = structure(list(structure(list(structure(c(299434.130314458, 
                                                                300531.43655987, 299434.130314458, 5046816.92873926, 5047257.53966348, 
                                                                5046816.92873926), dim = 3:2), structure(c(299434.130314458, 
                                                                                                           300401.157828111, 299434.130314458, 5046816.92873926, 5046249.12770288, 
                                                                                                           5046816.92873926), dim = 3:2)), class = c("XY", "MULTILINESTRING", 
                                                                                                                                                     "sfg"))), n_empty = 0L, crs = structure(list(input = "EPSG:32188", 
                                                                                                                                                                                                  wkt = "PROJCRS[\"NAD83 / MTM zone 8\",\n    BASEGEOGCRS[\"NAD83\",\n        DATUM[\"North American Datum 1983\",\n            ELLIPSOID[\"GRS 1980\",6378137,298.257222101,\n                LENGTHUNIT[\"metre\",1]]],\n        PRIMEM[\"Greenwich\",0,\n            ANGLEUNIT[\"degree\",0.0174532925199433]],\n        ID[\"EPSG\",4269]],\n    CONVERSION[\"MTM zone 8\",\n        METHOD[\"Transverse Mercator\",\n            ID[\"EPSG\",9807]],\n        PARAMETER[\"Latitude of natural origin\",0,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8801]],\n        PARAMETER[\"Longitude of natural origin\",-73.5,\n            ANGLEUNIT[\"degree\",0.0174532925199433],\n            ID[\"EPSG\",8802]],\n        PARAMETER[\"Scale factor at natural origin\",0.9999,\n            SCALEUNIT[\"unity\",1],\n            ID[\"EPSG\",8805]],\n        PARAMETER[\"False easting\",304800,\n            LENGTHUNIT[\"metre\",1],\n            ID[\"EPSG\",8806]],\n        PARAMETER[\"False northing\",0,\n            LENGTHUNIT[\"metre\",1],\n            ID[\"EPSG\",8807]]],\n    CS[Cartesian,2],\n        AXIS[\"easting (E(X))\",east,\n            ORDER[1],\n            LENGTHUNIT[\"metre\",1]],\n        AXIS[\"northing (N(Y))\",north,\n            ORDER[2],\n            LENGTHUNIT[\"metre\",1]],\n    USAGE[\n        SCOPE[\"Engineering survey, topographic mapping.\"],\n        AREA[\"Canada - Quebec between 75°W and 72°W.; Canada - Ontario - east of 75°W.\"],\n        BBOX[44.98,-75,62.53,-72]],\n    ID[\"EPSG\",32188]]"), class = "crs"), class = c("sfc_MULTILINESTRING", 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      "sfc"), precision = 0, bbox = structure(c(xmin = 299434.130314458, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                ymin = 5046249.12770288, xmax = 300531.43655987, ymax = 5047257.53966348
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      ), class = "bbox"))), row.names = 1L, sf_column = "geom", agr = structure(c(Name = NA_integer_, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  description = NA_integer_, timestamp = NA_integer_, begin = NA_integer_, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  end = NA_integer_, altitudeMode = NA_integer_, tessellate = NA_integer_, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  extrude = NA_integer_, visibility = NA_integer_, drawOrder = NA_integer_, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  icon = NA_integer_, sentier = NA_integer_, layer = NA_integer_, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  path = NA_integer_), class = "factor", levels = c("constant", 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    "aggregate", "identity")), class = c("sf", "data.frame"))

我有一个包含命名数据框的命名数据列表。

mlst = list(test = list(df = data.frame(x = 1:10, y = 21:30), list(c(1:2))),
            test2 = list(df = data.frame(x = 1:10, y = 21:30), list(c(1:2))))
mlst$test$df
mlst$test2$df

该功能do.call(rbind,mlst)不起作用，因为它不仅仅拾取数据帧。如何在没有 for 循环的情况下仅绑定数据帧的行？

在这个网站上https://www.quebec.ca/agriculture-environnement-et-ressources-naturelles/faune/gestion-faune-habitats-fauniques/especes-fauniques-menacees-vulnerables/liste，有我的物种表想要提取。

library(rvest)
sp.list = "https://www.quebec.ca/agriculture-environnement-et-ressources-naturelles/faune/gestion-faune-habitats-fauniques/especes-fauniques-menacees-vulnerables/liste"
# Get website
wp.list = read_html(species.list)
# Extract name of sections
headers = wp.list %>%  html_elements("h3") %>% html_text2() %>%   .[1:24]
# Get tables
tab = read_html(sp.list) %>% html_table(header = TRUE)
# Name tables
names(tab) = headers
# Combine tables
tab.gr = dplyr::bind_rows(tab, .id = "group")

这使：

tab.gr
# A tibble: 180 × 3
   group      Espèce                     `Nom latin`             
   <chr>      <chr>                      <chr>                   
 1 Mollusques Anodonte du gaspareau      Utterbackiana implicata 
 2 Mollusques Obovarie olivâtre          Obovaria olivaria       
 3 Insectes   Bourdon à tache rousse     Bombus affinis          
 4 Insectes   Coccinelle à neuf points   Coccinella novemnotata

我能够获取节标题h2，但无法将它们与每个h3节相关联

get.section = wp.list %>%  html_nodes('.frame, .frame-default, .frame-type-textmedia, .frame-layout-0')
pas.dans.cette.page = !grepl(pattern = "Dans cette", x = get.section)
subset.listes = get.section[pas.dans.cette.page]
sections.tables = subset.listes[grep(pattern = "Liste des esp", x = subset.listes)]
sections.tables %>%  html_elements("h2") %>%   html_text2()
[1] "Liste des espèces menacées"                                                   
[2] "Liste des espèces vulnérables"                                                
[3] "Liste des espèces susceptibles d’être désignées comme menacées ou vulnérables"

那么我怎样才能获得标题（例如，“Liste des espèces menacées”）及其组（例如，“Mollusques”）及其表格？

我有列表（元素数量不均匀）：

my.list = list(col1 = c("CC", "CT", "TT"), 
     col2 = c("GG", "GT"), 
     col3 = c("CC", "CT"),
     col4 = c("CC", "CG", "GG"), 
     col5 = c("AC", "CC"),
     col6 = "GG")

$col1
[1] "CC" "CT" "TT"

$col2
[1] "GG" "GT"

$col3
[1] "CC" "CT"

$col4
[1] "CC" "CG" "GG"

$col5
[1] "AC" "CC"

$col6
[1] "GG"

可以将其转换为数据框：

mylist.df = plyr::ldply(my.list, rbind)
names(mylist.df) <- c("cols","g1", "g2", "g3")

我想使用mylistor对下面的数据框进行子集化mylist.df。基本上，我想保留每个值至少有一个元素的每一行mylist：

df.to.subset = structure(list(IDs = c("ID1", "ID2", "ID3", "ID4", "ID5", "ID6"), 
               gr = c("gr1", "gr1", "gr1", "gr1", "gr1", "gr1"), 
               var = c(-3.451, -3.469, -3.837, -3.344, -3.904, -3.943), 
               col1 = structure(c(1L, 2L, 3L, 1L, 2L, 2L), levels = c("CC", "CT", "TT"), class = "factor"), 
               col2 = structure(c(1L, 1L, 2L, 3L, 3L, 3L), levels = c("GG", "GT", "TT"), class = "factor"), 
               col3 = structure(c(1L, 2L, 1L, 1L, 1L, 1L), levels = c("CC", "CT"), class = "factor"), 
               col4 = structure(c(2L, 2L, 2L, 2L, 2L, 2L), levels = c("CC", "CG", "GG"), class = "factor"), 
               col5 = structure(c(1L, 2L, 2L, 2L, 2L, 2L), levels = c("AC", "CC"), class = "factor"), 
               col6 = structure(c(1L, 1L, 2L, 1L, 1L, 1L), levels = c("GG","AA"), class = "factor")), 
          row.names = c(NA, 
                        -6L), class = c("tbl_df", "tbl", "data.frame"))

  IDs   gr      var col1  col2  col3  col4  col5  col6 
  <chr> <chr> <dbl> <fct> <fct> <fct> <fct> <fct> <fct>
1 ID1   gr1   -3.45 CC    GG    CC    CG    AC    GG   
2 ID2   gr1   -3.47 CT    GG    CT    CG    CC    GG   
3 ID3   gr1   -3.84 TT    GT    CC    CG    CC    AA   
4 ID4   gr1   -3.34 CC    TT    CC    CG    CC    GG   
5 ID5   gr1   -3.90 CT    TT    CC    CG    CC    GG   
6 ID6   gr1   -3.94 CT    TT    CC    CG    CC    GG   

（最终结果将是）

  IDs   gr      var col1  col2  col3  col4  col5  col6 
  ID1   gr1   -3.45 CC    GG    CC    CG    AC    GG   
  ID2   gr1   -3.47 CT    GG    CT    CG    CC    GG   

另外，我想重新调整每一列的级别以df.to.subset匹配此数据框中的级别：

factor.levels.cols = structure(list(cols = c("col1", "col2", "col3", "col4", "col5", "col6"), 
               g1 = c("CC", "GG", "CC", "CC", "AA", "AA"), 
               g2 = c("CT", "GT", "CT", "CG", "AC", "AG"), 
               g3 = c("TT", "TT", "TT", "GG", "CC", "GG")), 
          row.names = c(NA, 6L), class = "data.frame")

  cols g1 g2 g3
1 col1 CC CT TT
2 col2 GG GT TT
3 col3 CC CT TT
4 col4 CC CG GG
5 col5 AA AC CC
6 col6 AA AG GG

这里是否强制使用 for 循环，或者有没有办法让它更快？我有超过 1,000,000 个条目需要修改。

我想使用facet_wrap 在x 轴上为不同的组绘制不同的值。但是，使用 时scale = "free_x"，它会显示每个组内的唯一值。请参阅下面的示例：

library(ggplot2)
set.seed(1234)
nb = rep(LETTERS[1:3],4)
expand.grid(LETTERS[1:3], 1:3)
df = data.frame(ps = paste(rep(c("ps1","gc1"),6)),
                cr = rep(LETTERS[1:3],4),
                id = rep(x = month.abb[1:4], each = 3));df
df = df[order(df$ps),]
df[df$ps == "ps1","cr"] <- sample(LETTERS[4:6], size = 6, replace = TRUE)
df.all = rbind(df,df,df,df,df,df)
df.all$val = rnorm(n = nrow(df.all))

ggplot(df.all, 
       aes(x = cr,
           y = val)) + 
  geom_violin() +
  facet_wrap(vars(ps, id), 
             scales = "free_x",
             ncol = 4) +
  geom_point(position = position_jitter(width = 0.1, height = 0.1), 
             alpha= .3)

在此处的图像中（这是上面代码的输出），我添加了缺少的级别。基本上，有一个组“gc1”，我希望其中的级别不要下降。但我也不希望“ps1”中的级别出现在“gc1”中。所以最后 gc1 应该只显示级别 A、B、C，而 ps1 应该只显示 D、E 和 F。有没有办法做到这一点？