如何修复使用read.table函数时的错误

Question

我试图使用read.table函数read.table("https://www.fhwa.dot.gov/bridge/nbi/2020/AL20.txt", )将这个数据集读入r中，我得到了这个错误。

扫描中的错误(文件=文件，什么=什么，sep =9月，引号=引号，dec = dec，：第1行没有22个元素

我是否使用正确的函数读取这些数据？如果我是，我该怎么解决这个问题？指向试图读取的数据集的链接是https://www.fhwa.dot.gov/bridge/nbi/2020/AL20.txt。

Answer 1

该数据不以空格、制表符、逗号或分号分隔.它似乎是固定宽度的格式。为此，您必须知道或推断列的宽度。我已经猜到了基于几行，但您需要验证的是，事情并没有不必要的分裂或保持在一起。

此外，第10行有一个嵌入的#字符，因此必须禁止使用comment.char="#"的许多R解析函数的默认行为，否则将得到Error: line 10 did not have 24 elements。

尝尝这个,

widths <- diff(c(0,9,18,37,62,80,105,117,127,277,295,298,301,305,309,313,331,338,355,359,373,385,389,433,445))
dat <- read.fwf("https://www.fhwa.dot.gov/bridge/nbi/2020/AL20.txt", widths = widths, comment.char = "")
head(dat, n = 20)
#           V1        V2                  V3                        V4                 V5                        V6           V7         V8                                                                                                                                                     V9                V10 V11 V12  V13  V14  V15          V16  V17               V18  V19            V20          V21 V22                                          V23          V24
# 1  014000000 00000S702 1610400700905300000 PERDIDO CREEK             IRR BIA RTE 4007   11.4KM NW OF ATMORE, AL   999900015000 0000000000 00310610940873413480033626209199902000000502019500970300111150000000000A15505000001000009700147000150000000009700979999N0000N0000008876N2445232777N588    000000021924N   N   N     NA   NA   NA 0.000000e+00 2019 0                 0N2  0100002601010  Y80000592039   0 Y62                                          G70000014550
# 2  014000000 00000S703 1610400300905303004 PERDIDO CREEK             IRR BIA RTE 4003   ON LYNN MCGEE ROAD        999900011000 0000000000 00310620200873408900033626209200202000001592019500650000111150000000000A15501000001000009700129000136003003009100989999N0000N0000008877N2848235176N578    000000021924N   N   N     NA   NA   NA 0.000000e+00 2019 0                 0N2  0100002608010  Y80002002039   0 Y62                                          G70000013328
# 3  014000000 0000M0022 1810000000011319000 UCHEE CREEK               101ST AIRBORNE RD  3.4 KM S OF SUNSHINE RD   999900000000            0032174330-0845837.0183747409194202000003752017401040000001150000000000A15104000003000007300183000430006006007300909999N0000N0000005566N2517237255N586 381000528101924N   Y60 N     NA 1017   NA 1.000001e+12 2019                   0N2  0000001100350  Y50004002039  NA Y74                                          F50000038700
# 4  014000000 883039900 1410008800205900000 LITTLE BEAR CR. DAM SPW   CO. RD 88          LITTLE BEAR CR DAM        999900000000            0034270600087581200016367670819740200000430201750116099011115N000000000A19505000005000008600140000655000000008701059999N0000N0000007777N1442126665N596          061824N   N   N     NA   NA   NA           NA   NA                   0N2  0000001000050  Y50006002037  NA Y67                                          G70000068775
# 5  014000001 014002450 1310010100207900000 TENNESSEE RIVER           SR 101             ON WHEELER DAM             45200394290            00344818000872254000423676706193702000055202017400790000100041017900335A55310302002014306000533019812009002006100780452N0000N0000005659N1400123952N588 311019812061924Y24 N   N    619   NA   NA 5.000000e+16   NA                   0N2  00196210001001 Y50090002037  NA Y67                                          F50001545336
# 6  014000001 331700710 1620000000203300000 TENNESSEE RIVER           Res Rd             ON WILSON DAM             999900000000            00344800000873730000063676717192402020036202018300790000111111017300335A56403120008007806000469015124017005006100839999H1219H6000005558N15841350529593 311015124061824Y24 N   N    618   NA   NA 3.500000e+16   NA                   0N2  00195815000801 Y50025002038  NA Y67                                          F50001255292
# 7  014000002           1410000001012700000 BLACKWATER CREEK          COUNTRY CLUB ROAD  1 MILE EAST HWY 195        45700000100 000CO00000 00335430300871717700023020209189801000004001991100520000000020000000000P15310302001000403700305000518000000003700370457N0000N0000006457N1027101822N072 311000621101924Y24 N   Y03 1019   NA  120 5.110001e+14 2020 0 _               0N3  0000006600010  Y50005602032   0 N01                                          P40000019166
# 8  014000004           1410000001012700000 LOST CREEK                KINGS MILL ROAD    1 MILE N OAKMAN HWY        40200000100 000CO00000 00334409500872134600133020209190001000001501991200490000000050000000000K15310302001000503700256000482000000003700370402N0000N0000004446N5000500000N082 311000583011324Y24 N   Y03  213   NA  113 4.800000e+14 2020 0 _               0N3  0000006800010  YU0002102033   0 N01                                          P40000017834
# 9  014000004 504800350 1680000000109500000 LITTLE PAINT ROCK CREEK   LOCK ACCESS ROAD   0.3 MI SOUTH US 431       999900056330            00342818000862230001993676709193902000003502018400610000100050000000000A15104000001000007300183000192003003007000829999N0000N0000007776N1477128874N568          121824N   N   N     NA   NA   NA           NA   NA                   0N2  0000001600050  Y50003752038  NA Y67                                          G70000015744
# 10 014000005           1500000001007548808 STREAM                    RAILROAD STREET    0.5 MI E SR#17            999900004990 000MU00040 00333357210880425781583040409190001000000152007100300000000050000000000P15410000002000004400079000155000000004400489999N0000N9990005445N1027101826N045 311000223061924Y24 N   Y12  619   NA  619 2.300000e+14 2020 0 _               0N3  0000008700000  Y40000592032   0 N01                                          P40000007440
# 11 014000007           1410001000104900000 COAL   CREEK              CO  RT  10         1.25  MI N ARONEY  T9SR5E 999900000100 000CO00100 00341403150860413920053020208199301000001802017500580000111150000000000A15122000003000007500073000219000000007500759999N0000N0000007675N1637138265N576    000300031924N   N   N     NA   NA   NA 4.930000e+14 2020 0 _               0N3  0000002000050  Y50002682037   0 N01                                          F60000016425
# 12 014000008           1410002700500700000 VIADUCT OVER SO.RR        COUNTY 27          OLD AL 5 AT WOODSTK       999900000100 000CO00270 0033122146087091361010302020919270200000513198920085000000002N000000000P12303104001000306100332000652000000006100709999R0914R183061777NN213620952390N7 311000756101924Y12 N   Y12 1019   NA 1019 1.192000e+15 2020 0 _               0N2  0000001000200  YN0007652030   0 N01                                          G70000045640
# 13 01400000B 253040000 1410003700205900000 BEAR CREEK DAM SPILLWAY   CO. RD 37          BEAR CREEK DAM            999900000000            0034235400087590600021367670819690200000430201750116000010115N000000000A19505000008000008500143001170000000008500969999N0000N0000007677N1489129265N596          061824N   N   N     NA   NA   NA           NA   NA                   0N2  0000002600050  Y50006002037  NA Y67                                          F60000112320
# 14 01400000B LN0BR0010 1880000000107100000 TOWN CREEK                BELLEFONTE ROAD    Bellefonte                999900000000            003443470008554570001136767091974020000025020184012800000N0N50000000000A15119000002000006400030000064000000000000009999N0000N000000NNN76337332886NN577          031924N   Y60 N     NA  716   NA 0.000000e+00   NA                   0N2  000000N6NN010  Y50005002038  NA Y67                                          F60000008192
# 15 01400000T 721700150 1680000000203300000 CANE CREEK                Access Road        Colbert Steam Plant       999900000000            003444120008750540019936767091953020000010020184006703001NN050000000000A15104000005000007300162000808006006007300919999N0000N0000006666N1464127966N598          061824N   Y60 N     NA  819   NA           NA   NA                   0N2  0000001000100  Y50001002038  NA Y67                                          F60000073528
# 16 014000012           1410009100107109328 SOUTHERNLNRAILROAD        JC91               1001E US 72               999900000100 000CO00910 0034563691086433691002304040919000200000495200710073000000002N000000000A12101101003000206100101000363000000006100699999R0678R320000566NN043503276345N6 351000455011924N   N   Y12   NA   NA  120 6.860001e+14 2020 0 _               0N2  0000001000150  YN0005002039   0 N01                                          F50000025047
# 17 014000013 771700120 1600000000203300000 BUS BAR TUNNEL- REMOVED   TVA RES. ROAD      NEAR NAT. FERT. DEV. CTR. 999900000000            0034465400087390000005367671919580200003620201860073000011115N000000000A10302000001000007900177000189006006007900989999N0000N000000677NN1551133073N5N7 331000189061824N   N   N     NA   NA   NA 1.800000e+14   NA                   0N2  0000001600070  YN0045002038  NA Y67                                          F60000018522
# 18 014000019           1410043800108900000 RODGERS BRANCH            JACKS RD           1 MI SE NEW MARKET        999900000100 000CO04380 00345334170862519520053020209190002000002501992200790450000050000000000A15319000002000007600073000146000000000000769999N0000N000000NNN55135712885NN555 311000214081824N   N   N     NA   NA   NA 4.070000e+14 2020 0 _               0N2  000000NNNN010  Y80002902035   0 N01                                          F50000011096
# 19 014000022           1410004500104900000 LAUREL  CREEK             CO RD 313          1.3MI S GILBERT XRDT8SR7E 999900000100 000CO00450 00342101790855522060053020209190201000000872017000400000000050000000000K15302000001000099900085000085000000003400379999N0000N0000006655N1000100003N048 311000152111724N   N   Y12   NA   NA 1117 1.250000e+14 2020 0 _               0N3  0000008700000  Y50001292037   0 N01                                          F50000003145
# 20 014000024           1510000000311707000 LITTLE CAHABA RIVER       CAHABA BEACH ROAD  1.8 MILES NORTH OF US 280  47500005000 000MU01630 00332623190864157360063040419190401000001001996000490000000030000000000K15310000001000003500335000335000000003500359999N0000N0000005254N2000200003N066 311000423101924Y24 N   Y03  990   NA  996 3.190000e+14 2020 0 _               0N3  0000008700010  Y60001382019   0 N01                                          P20000011725

要将其分解为必需的列，很容易就会有更多的工作要做。例如，V9看起来很长，并且有某种模式，因此可以很容易地将几个列连在一起。

另外，我还通过数字符为上面的widths创建了数字。我认为有一些工具可以很好地提示如何开始使用FWF文件(在FWF文件中，有些列没有将其与下一列分隔开来的空间)，但它从来都不是确定性的。唯一能确定的方法就是知道数据。