{"id":266,"date":"2022-05-13T01:49:46","date_gmt":"2022-05-12T17:49:46","guid":{"rendered":"https:\/\/blog.iiiz.org\/?p=266"},"modified":"2023-09-08T13:27:28","modified_gmt":"2023-09-08T05:27:28","slug":"r%e8%af%ad%e8%a8%80%e8%87%aa%e4%bd%9c%e7%ac%94%e8%ae%b0","status":"publish","type":"post","link":"https:\/\/blog.ineuro.net\/index.php\/2022\/05\/13\/266\/","title":{"rendered":"R\u8bed\u8a00\u81ea\u4f5c\u7b14\u8bb0"},"content":{"rendered":"

R\u8bed\u8a00\u5b57\u6bcd\u5411\u91cf\uff1a
\nLETTERS: the 26 upper-case letters of the Roman alphabet;<\/p>\n

letters: the 26 lower-case letters of the Roman alphabet;<\/p>\n

month.abb: the three-letter abbreviations for the English month names;<\/p>\n

month.name: the English names for the months of the year;<\/p>\n

pi: the ratio of the circumference of a circle to its diameter.<\/p>\n

> e <- LETTERS[seq(,26)]\n> e\n [] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"<\/code><\/pre>\n
    \n
  1. R\u8bed\u8a00\u4e0b\u8f7d\u51fd\u6570
    \ndownload.file()\u51fd\u6570
    \ndownload.file(url,destfile,method,quiet=FALSE,mode="w",cacheOK=TRUE,extra=getOption("download.file.extra"))
    \nurl:\u5b57\u7b26\u4e32,\u5fc5\u987bhttp:\/\/,https:\/\/,ftp:\/\/,file:\/\/\u5f00\u5934<\/a>
    \ndestfile:\u4e0b\u8f7d\u6587\u4ef6\u7684\u4fdd\u5b58\u5730\u5740,\u9ed8\u8ba4\u5de5\u4f5c\u76ee\u5f55,file\u4e3a\u4fdd\u5b58\u6587\u4ef6\u540d
    \nmethod:\u63d0\u4f9b"internal","wget","curl","lynx","libcurl","wininet".windows\u4e0a\u901a\u5e38internal\u5c31\u80fd\u89e3\u51b3\u5927\u591a\u6570\u7684\u95ee\u9898,\u5c11\u6570\u641e\u4e0d\u5b9a\u7684\u5982Cygwin,gnuwin32\u7528"wget",windows\u4e8c\u8fdb\u5236\u6587\u4ef6\u7528"curl".method\u5bf9\u4e8eMac\u7528\u6237\u6765\u8bf4\u662f\u90fd\u8981\u8bbe\u7f6e\u7684."lynx"\u4e3b\u8981\u9488\u5bf9historical interest
    \nquiet:TRUE-\u7981\u6b62\u72b6\u6001\u6d88\u606f,\u663e\u793a\u8fdb\u5ea6\u6761
    \nmode:\u5199\u5165\u6587\u4ef6\u6a21\u5f0f,\u53ea\u80fd\u5728method="internal"\u65f6\u4f7f\u7528,"w"\/"wb"(binary)\/"a"(append)\/"ab"
    \ncacheOK:\u662f\u5426\u63a5\u53d7\u670d\u52a1\u5668\u7aef\u7684\u7f13\u5b58\u503c,\u5bf9http:\/\/,    https:\/\/\u4f7f\u7528.FALSE-\u5c1d\u8bd5\u4ece\u7ad9\u70b9\u83b7\u53d6\u526f\u672c,\u800c\u4e0d\u662f\u4ece\u4e2d\u95f4\u7f13\u5b58\u4e2d\u83b7\u53d6<\/a><\/p>\n
    download.file(\"http:\/\/github.com\/mgimond\/Spatial\/raw\/master\/Data\/Income_schooling.zip\",\n           destfile = \"Income_schooling.zip\" , mode='wb')\nunzip(\"Income_schooling.zip\", exdir = \".\")\nfile.remove(\"Income_schooling.zip\")<\/code><\/pre>\n<\/li>\n
  2. for\u5faa\u73af\u8981\u6ce8\u610f\u4f7f\u7528:length(x)<\/li>\n
  3. \u5224\u65ad\u67d0\u5411\u91cf\u4e2d\u662f\u5426\u5b58\u5728\u4e00\u4e2a\u5143\u7d20 if a %in% c()<\/li>\n
  4. R\u8bed\u8a00\u5982\u4f55\u5220\u9664\u5411\u91cf\u4e2d\u6307\u5b9a\u7684\u5143\u7d20\uff1a
    \n\u4f8b\u5982\u6253\u7b97\u4ece\u5411\u91cfA\u4e2d\u5220\u9664\u5143\u7d20"a"\uff0c\u7528match\uff08\uff09\u53ea\u83b7\u5f97\u4e86\u5b83\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u7d22\u5f15\u4e0b\u6807\uff0c\u7528which()\u83b7\u5f97\u5168\u90e8"a"\u7684\u7d22\u5f15\u4e0b\u6807\u3002<\/p>\n
    > A=c(\"a\",\"c\",\"e\",\"b\",\"d\",\"a\",\"b\",\"d\",\"f\",\"e\",\"g\")\n> match(\"a\",A)\n[] \n> match(c(\"a\"),A)\n[] \n> which(A==\"a\")\n[]  6<\/code><\/pre>\n
    \u800c\u5220\u9664\u7684\u64cd\u4f5c\u4ec5\u9700\u8981\u8fdb\u884c\u5728\u5411\u91cf\u4e2d\u5199\u5165\u8d1f\u7684\u7d22\u5f15\u4e0b\u6807\u5373\u53ef\uff0c\u5982\u5220\u9664\u6240\u6709\u7684"a"\uff1a<\/p>\n
    > B=A[-which(A==\"a\")]\n> B\n[] \"c\" \"e\" \"b\" \"d\" \"b\" \"d\" \"f\" \"e\" \"g\"<\/code><\/pre>\n
    \u5982\u679c\u662f\u60f3\u5220\u9664\u591a\u4e2a\u5143\u7d20\uff0c\u53ef\u4ee5\u7528\u5faa\u73af\u6765\u5b8c\u6210<\/p>\n
    > C=A\n> a=c(\"a\",\"b\",\"g\")\n> for(i in a){C=C[-which(C==i)]}\n> C\n[] \"c\" \"e\" \"d\" \"d\" \"f\" \"e\"<\/code><\/pre>\n
    6.R\u8bed\u8a00\u6dfb\u52a0\u65b0\u7684\u5217\uff0c\u4f7f\u7528transform\u51fd\u6570“`r<\/p>\n
    frame <- transform(frame,sum=a+b,mean=(a+b)\/2)\n> frame\na b sum mean\n 2  .0\n2 3 2   5  2.5\n3 5 3   8  4.0<\/code><\/pre>\n
    Dyplr\u5305<\/h1>\n
    select() \u4ece\u6570\u636e\u4e2d\u9009\u62e9\u5217
    \nfilter() \u6570\u636e\u884c\u7684\u5b50\u96c6
    \ngroup_by() \u6c47\u603b\u6570\u636e
    \nsummarise() \u6c47\u603b\u6570\u636e\uff08\u8ba1\u7b97\u6c47\u603b\u7edf\u8ba1\u4fe1\u606f\uff09
    \narrange() \u6392\u5e8f\u6570\u636e
    \nmutate() \u521b\u5efa\u65b0\u53d8\u91cf<\/li>\n<\/ol>\n
    dplyr\u53ef\u4ee5\u65b9\u4fbf\u5730\u62bd\u53d6\u6570\u636e\u6846\u7684\u5b50\u96c6\u3002\u62bd\u53d6\u884c\u7684\u5b50\u96c6\u51fd\u6570\u6709filter\uff0cdistinct\uff0csample_frac\uff0csample_n\uff0cslice\uff0ctop_n\u3002\u62bd\u53d6\u5217\u7684\u5b50\u96c6\u51fd\u6570\u662fselect\uff0c\u53ef\u901a\u8fc7\u5217\u540d\u6216\u9009\u9879\u51fd\u6570\u8fdb\u884c\u9009\u62e9<\/p>\n
    filter()\u51fd\u6570\u53ea\u80fd\u5c06\u6307\u5b9a\u6761\u4ef6\u7684\u89c2\u6d4b\u7b5b\u9009\u51fa\u6765\uff0c\u5e76\u4e0d\u80fd\u7b5b\u9009\u51fa\u53ea\u5173\u5fc3\u7684\u53d8\u91cf\uff0c\u4e3a\u4e86\u5f25\u8865\u8fd9\u4e2a\u7f3a\u9677\uff0c\u53ef\u4ee5\u4f7f\u7528select()\u51fd\u6570\u7b5b\u9009\u6307\u5b9a\u7684\u53d8\u91cf\uff0c\u800c\u4e14\u6bd4subset()\u51fd\u6570\u66f4\u7075\u6d3b\uff0c\u800c\u4e14\u9009\u62e9\u53d8\u91cf\u7684\u540c\u65f6\u4e5f\u53ef\u4ee5\u91cd\u65b0\u547d\u540d\u53d8\u91cf\u3002\u5982\u679c\u5254\u9664\u67d0\u4e9b\u53d8\u91cf\u7684\u8bdd\uff0c\u53ea\u9700\u5728\u53d8\u91cf\u524d\u52a0\u4e0a\u8d1f\u53f7\u201c-\u201d\u3002\u4e4b\u6240\u4ee5\u8bf4\u4ed6\u6bd4subset()\u51fd\u6570\u7075\u6d3b\uff0c\u662f\u56e0\u4e3a\u53ef\u4ee5\u5728select()\u51fd\u6570\u4f20\u9012\u5982\u4e0b\u53c2\u6570\uff1a
    \nstarts_with(x, ignor.case = TRUE)#\u9009\u62e9\u4ee5\u5b57\u7b26x\u5f00\u5934\u7684\u53d8\u91cf<\/p>\n
    ends_with(x, ignor.case = TRUE)#\u9009\u62e9\u4ee5\u5b57\u7b26x\u7ed3\u5c3e\u7684\u53d8\u91cf<\/p>\n
    contains(x, ignor.case = TRUE)#\u9009\u62e9\u6240\u6709\u5305\u542bx\u7684\u53d8\u91cf<\/p>\n
    matches(x, ignor.case = TRUE)#\u9009\u62e9\u5339\u914d\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u53d8\u91cf<\/p>\n
    num_range('x', :5, width = 2)#\u9009\u62e9x0\u5230x05\u7684\u53d8\u91cf<\/p>\n
    one_of('x','y','z')#\u9009\u62e9\u5305\u542b\u5728\u58f0\u660e\u53d8\u91cf\u4e2d\u7684<\/p>\n
    everything()#\u9009\u62e9\u6240\u6709\u53d8\u91cf\uff0c\u4e00\u822c\u8c03\u6574\u6570\u636e\u96c6\u4e2d\u53d8\u91cf\u987a\u5e8f\u65f6\u4f7f\u7528<\/p>\n
    \u901a\u8fc7mulate()\u51fd\u6570\u53ef\u4ee5\u5728\u539f\u59cb\u6570\u636e\u96c6\u7684\u57fa\u7840\u4e0a\u6269\u5c55\u65b0\u53d8\u91cf\uff0c\u7c7b\u4f3c\u4e8etransform()\u51fd\u6570\uff0c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n
    mutate(.data, …)<\/p>\n
    \u4f8b\u5b50\uff1a
    \nmutate(df2tbl, z = y^2 + y – 0)
    \n\u540c\u6837\u53ef\u4ee5\u8fdb\u884c\u6570\u636e\u6269\u5c55\u7684\u8fd8\u6709transmute()\u51fd\u6570\uff0c\u4e0emutate()\u51fd\u6570\u4e0d\u540c\u7684\u662f\uff0c\u8be5\u51fd\u6570\u6269\u5c55\u65b0\u53d8\u91cf\u7684\u540c\u65f6\uff0c\u5c06\u5220\u9664\u6240\u6709\u539f\u59cb\u53d8\u91cf\u3002
    \n\u76f8\u5173\u5ef6\u5c55\u51fd\u6570\uff1atransmute\u3001mutate_all\u3001mutate_if\u3001mutate_at
    \nmutate_all()\u2014\u2014\u5e94\u7528\u51fd\u6570\u5230\u6240\u6709\u5217
    \n\u5c06\u6240\u6709\u5217\u8f6c\u5316\u4e3a\u5c0f\u5199\uff1a<\/p>\n
    msleep %>%\n  mutate_all(tolower)<\/code><\/pre>\n
    mutate_if()\u2014\u2014\u5e94\u7528\u51fd\u6570\u5230\u6ee1\u8db3\u6761\u4ef6\u7684\u5217
    \n\u5c06\u6240\u6709 Double \u578b\u7684\u5217\uff0c\u8f6c\u5316\u4e3a Integer\uff1a<\/p>\n
    iris %>%\n  mutate_if(is.double, as.integer)<\/code><\/pre>\n
    \u4f7f\u7528 as.numeric \u8f6c\u4e3a\u6570\u5b57\u578b\u65f6\u5efa\u8bae\u52a0\u4e0aas.character<\/p>\n
    R\u8bed\u8a00\u4e2d\u63d2\u5165\u5143\u7d20\u4f7f\u7528\u7684\u662fappend()\u65b9\u6cd5<\/p>\n
    a <- c(:0)\n> append(x = a, , after = 5)\n []    2  3  4  5   6  7  8  9 0<\/code><\/pre>\n
    assign\u51fd\u6570\u662f\u5c06\u6570\u503c\u8d4b\u503c\u7ed9<\/strong>\u4fdd\u5b58\u5728\u5b57\u7b26\u4e32\u53d8\u91cf\u4e2d\u7684\u53d8\u91cf\u540d
    \nlapply\u662f\u7528\u4e8e\u628a\u6307\u5b9a\u7684\u5f85\u5e94\u7528\u7684\u51fd\u6570\u5e94\u7528\u4e8e\u5217\u8868\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20\uff0c\u5e76\u8fd4\u56de\u5217\u8868\u7ed3\u6784\u7684\u8f93\u51fa<\/p>\n
    #\u5e94\u7528lapply\n\nexp = lapply(mylist, median)#median\u4e3a\u6211\u4eec\u5c06\u5e94\u7528\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u6362\u6210\u81ea\u5df1\u7684\u51fd\u6570<\/code><\/pre>\n
    eval()\u53ef\u4ee5\u628a\u5b57\u7b26\u4e32\u8f6c\u5316\u6210\u8868\u8fbe\u5f0f\u6765\u6267\u884c\u3002
    \neval\u548cparse\u7ed3\u5408\u4f7f\u7528\uff0c\u53c2\u6570 text \u7b49\u4e8e\u8981\u8f6c\u5316\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n
    eval(parse(text ='LAB_Bm' ))<\/code><\/pre>\n
    cat()\u51fd\u6570\u5411\u63a7\u5236\u53f0\u8f93\u51fa\u6253\u5370\u5185\u5bb9\uff0c\u51fd\u6570\u6ca1\u6709\u8fd4\u56de\u503c\uff08=\u8fd4\u56de\u503c\u4e3aNULL\uff09\uff1b\u800cprint()\u51fd\u6570\u5728\u63a7\u5236\u53f0\u8f93\u51fa\u6253\u5370\u7684\u5185\u5bb9\uff0c\u540c\u65f6\u8fd4\u56de\u8f93\u51fa\u5185\u5bb9\u3002<\/p>\n
    \u6709\u4ee5\u4e0b\u4e24\u4e2a\u6848\u4f8b\u53ef\u4ee5\u5e2e\u52a9\u7406\u89e3\u4ed6\u4eec\u4e4b\u95f4\u7684\u5dee\u5f02\uff1a<\/p>\n
    e\u7684x\u6b21\u65b9exp(x)<\/code><\/p>\n
    mutate\u8fd8\u6709\u4e09\u4e2a\u884d\u751f\u51fd\u6570:
    \nmutate_at()\uff1b mutate_if()\uff1b mutate_all()
    \n\u5728\u5b98\u7f51\u4e0a\u7684\u5173\u4e8e\u8fd9\u4e09\u4e2a\u540e\u7f00\u7684\u89e3\u91ca\u5982\u4e0b\uff1a
    \n_all\uff1a affects every variable
    \n_at\uff1a affects variables selected with a character vector or vars()
    \n_if \uff1a affects variables selected with a predicate function:
    \n\u5176\u4e2d\uff0call\u662f\u9488\u5bf9\u6240\u6709\u5217\uff0cat\u662f\u9488\u5bf9\u7279\u5b9a\u7684\u5217\uff0cif\u7684\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u5217
    \n\u53c2\u6570\u5982\u4e0b\uff1a
    \nmutate_all(.tbl, .funs, …)
    \nmutate_if(.tbl, .predicate, .funs, …)
    \nmutate_at(.tbl, .vars, .funs, …, .cols = NULL)<\/p>\n
    \u6570\u636e\u805a\u5408<\/h1>\n
    \u4f7f\u7528summarize()\u51fd\u6570\u5b9e\u73b0\u6570\u636e\u96c6\u805a\u5408\u64cd\u4f5c
    \nmin()\uff1a\u8fd4\u56de\u6700\u5c0f\u503c<\/p>\n
    max()\uff1a\u8fd4\u56de\u6700\u5927\u503c<\/p>\n
    mean()\uff1a\u8fd4\u56de\u5747\u503c<\/p>\n
    sum()\uff1a\u8fd4\u56de\u603b\u548c<\/p>\n
    sd()\uff1a\u8fd4\u56de\u6807\u51c6\u5dee<\/p>\n
    median()\uff1a\u8fd4\u56de\u4e2d\u4f4d\u6570<\/p>\n
    IQR()\uff1a\u8fd4\u56de\u56db\u5206\u4f4d\u6781\u5dee<\/p>\n
    n()\uff1a\u8fd4\u56de\u89c2\u6d4b\u4e2a\u6570<\/p>\n
    n_distinct()\uff1a\u8fd4\u56de\u4e0d\u540c\u7684\u89c2\u6d4b\u4e2a\u6570<\/p>\n
    first()\uff1a\u8fd4\u56de\u7b2c\u4e00\u4e2a\u89c2\u6d4b<\/p>\n
    last()\uff1a\u8fd4\u56de\u6700\u540e\u4e00\u4e2a\u89c2\u6d4b<\/p>\n
    nth()\uff1a\u8fd4\u56den\u4e2a\u89c2\u6d4b<\/p>\n
    inner_join#\u5167\u8fde
    \nleft_join#\u5de6\u8fde
    \nright_join#\u53f3\u8fde
    \nfull_join#\u5168\u8fde
    \nsemi_join#\u8fd4\u56de\u80fd\u591f\u4e0ey\u8868\u5339\u914d\u7684x\u8868\u6240\u6709\u8bb0\u5f55
    \nanti_join#\u8fd4\u56de\u65e0\u6cd5\u4e0ey\u8868\u5339\u914d\u7684x\u8868\u7684\u6240\u8bb0\u5f55
    \nintersect(x, y): x \u548c y \u7684\u4ea4\u96c6\uff08\u6309\u884c\uff09
    \nunion(x, y): x \u548c y \u7684\u5e76\u96c6\uff08\u6309\u884c\uff09
    \nsetdiff(x, y): x \u548c y \u7684\u8865\u96c6 \uff08\u5728x\u4e2d\u4e0d\u5728y\u4e2d\uff09<\/p>\n
    \"\u56fe\u7247[1]-\u5403\u4e86\u5403\u4e86\"
    \n\"\u56fe\u7247[2]-\u5403\u4e86\u5403\u4e86\"<\/p>\n","protected":false},"excerpt":{"rendered":"
    R\u8bed\u8a00\u5b57\u6bcd\u5411\u91cf\uff1a LETTERS: the 26 upper-case letters of the Roma […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,24],"tags":[],"topics":[],"_links":{"self":[{"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/posts\/266"}],"collection":[{"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/comments?post=266"}],"version-history":[{"count":33,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/posts\/266\/revisions"}],"predecessor-version":[{"id":498,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/posts\/266\/revisions\/498"}],"wp:attachment":[{"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/media?parent=266"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/categories?post=266"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/tags?post=266"},{"taxonomy":"topics","embeddable":true,"href":"https:\/\/blog.ineuro.net\/index.php\/wp-json\/wp\/v2\/topics?post=266"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}