批量读入一个文件夹中文件的数据操作实例

批量处理

> coo = dir("test")

> path = "/panfs/TC_FUN/USER/group3/yanzengli/other/study/R_study/knowledge/test"

> doc_path = sapply(coo, function(names) paste(path, names, sep='/'))

>doc <- sapply( doc_path, function(doc) readLines(doc) )

详解：

dir 函数作用：把所有目录下的文件名装入一个数组，效果如下：

> coo

[1] "co_1.txt" "co_2.txt" "co_3.txt"

paste函数作用：把一串字符连成一个，在这儿是把连接成完整的路径，效果如下：

> doc_path

co_1.txt

"/panfs/TC_FUN/USER/group3/yanzengli/other/study/R_study/knowledge/test/co_1.txt"

co_2.txt

"/panfs/TC_FUN/USER/group3/yanzengli/other/study/R_study/knowledge/test/co_2.txt"

co_3.txt

"/panfs/TC_FUN/USER/group3/yanzengli/other/study/R_study/knowledge/test/co_3.txt"

sapply函数作用：相当于perl中的foreach语句，循环使用某变量中元素，然后返回所有的内容。

但是有个缺点，当存在多个文件的时候，会并排所有的结果，这个是个致命的缺点，不过反正已经

读入数据了，后面可以用变量来处理，毕竟是已经把所有的数据都已经读入一个矩阵，效果如下：

> doc

      co_1.txt  co_2.txt  co_3.txt

 [1,] "1\t657"  "31\t609" "61\t834"

 [2,] "2\t593"  "32\t584" "62\t724"

 [3,] "3\t550"  "33\t589" "63\t785"

 [4,] "4\t751"  "34\t532" "64\t812"

 [5,] "5\t647"  "35\t529" "65\t643"

 [6,] "6\t492"  "36\t507" "66\t846"

 [7,] "7\t595"  "37\t973" "67\t883"

 [8,] "8\t430"  "38\t587" "68\t836"

 [9,] "9\t533"  "39\t365" "69\t723"

[10,] "10\t398" "40\t690" "70\t693"

[11,] "11\t541" "41\t575" "71\t925"

[12,] "12\t489" "42\t496" "72\t823"

[13,] "13\t632" "43\t529" "73\t880"

[14,] "14\t530" "44\t805" "74\t813"

[15,] "15\t705" "45\t971" "75\t786"

[16,] "16\t730" "46\t900" "76\t801"

[17,] "17\t537" "47\t873" "77\t891"

[18,] "18\t566" "48\t773" "78\t762"

[19,] "19\t610" "49\t865" "79\t777"

[20,] "20\t458" "50\t710" "80\t866"

[21,] "21\t424" "51\t734" "81\t684"

[22,] "22\t406" "52\t980" "82\t855"

[23,] "23\t630" "53\t660" "83\t880"

[24,] "24\t698" "54\t844" "84\t908"

[25,] "25\t520" "55\t907" "85\t746"

[26,] "26\t520" "56\t657" "86\t846"

[27,] "27\t587" "57\t676" "87\t951"

[28,] "28\t538" "58\t796" "88\t815"

[29,] "29\t411" "59\t712" "89\t544"

[30,] "30\t483" "60\t769" "90\t794"

好了，先这样吧，后面还有一个介绍怎么把图片输出到pdf或者svg，很有用滴。