我遇到问题如何删除txt文件中的几行然后转换为带有R的csv，因为我只想从txt获取数据。 我的代码无法删除，因为它删除了包含数据日期的行
这里使用的代码
setwd("D:/tugasmaritim/")
FILES <- list.files( pattern = ".txt")
for (i in 1:length(FILES)) {
l <- readLines(FILES[i],skip=4)
l2 <- l[-sapply(grep("</PRE><H3>", l), function(x) seq(x, x + 30))]
l3 <- l2[-sapply(grep("<P>Description", l2), function(x) seq(x, x + 29))]
l4 <- l3[-sapply(grep("<HTML>", l3), function(x) seq(x, x + 3))]
write.csv(l4,row.names=FALSE,file=paste0("D:/tugasmaritim/",sub(".txt","",FILES[i]),".csv"))
}
<HTML>
<TITLE>University of Wyoming - Radiosonde Data</TITLE>
<LINK REL="StyleSheet" HREF="/resources/select.css" TYPE="text/css">
<BODY BGCOLOR="white">
<H2>96749 WIII Jakarta Observations at 00Z 02 Oct 1995</H2>
<PRE>
-----------------------------------------------------------------------------
PRES HGHT TEMP DWPT RELH MIXR DRCT SKNT THTA THTE THTV
hPa m C C % g/kg deg knot K K K
-----------------------------------------------------------------------------
1011.0 8 23.2 22.5 96 17.30 0 0 295.4 345.3 298.5
1000.0 98 23.6 22.4 93 17.39 105 8 296.8 347.1 299.8
977.3 300 24.6 22.1 86 17.49 105 8 299.7 351.0 302.8
976.0 311 24.6 22.1 86 17.50 104 8 299.8 351.2 303.0
950.0 548 23.0 22.0 94 17.87 88 12 300.5 353.2 303.7
944.4 600 22.6 21.8 95 17.73 85 13 300.6 352.9 303.8
925.0 781 21.2 21.0 99 17.25 90 20 301.0 351.9 304.1
918.0 847 20.6 20.6 100 16.95 90 23 301.0 351.0 304.1
912.4 900 20.4 18.6 89 15.00 90 26 301.4 345.7 304.1
897.0 1047 20.0 13.0 64 10.60 90 26 302.4 334.1 304.3
881.2 1200 19.4 11.4 60 9.70 90 26 303.3 332.5 305.1
850.0 1510 18.2 8.2 52 8.09 95 18 305.2 329.9 306.7
845.0 1560 18.0 7.0 49 7.49 91 17 305.5 328.4 306.9
810.0 1920 15.0 9.0 67 8.97 60 11 306.0 333.4 307.7
792.9 2100 14.3 3.1 47 6.06 45 8 307.1 325.9 308.2
765.1 2400 13.1 -6.8 24 3.01 40 8 309.0 318.7 309.5
746.0 2612 12.2 -13.8 15 1.77 38 10 310.3 316.2 310.6
712.0 3000 10.3 -15.0 15 1.69 35 13 312.3 318.1 312.6
700.0 3141 9.6 -15.4 16 1.66 35 13 313.1 318.7 313.4
653.0 3714 6.6 -16.4 18 1.63 32 12 316.0 321.6 316.3
631.0 3995 4.8 -2.2 60 5.19 31 11 317.0 333.9 318.0
615.3 4200 3.1 -3.9 60 4.70 30 11 317.4 332.8 318.3
601.0 4391 1.6 -5.4 60 4.28 20 8 317.8 331.9 318.6
592.9 4500 0.6 -12.0 38 2.59 15 6 317.9 326.6 318.4
588.0 4567 0.0 -16.0 29 1.88 11 6 317.9 324.4 318.3
571.0 4800 -1.2 -18.9 25 1.51 355 5 319.1 324.4 319.4
549.8 5100 -2.8 -22.8 20 1.12 45 6 320.7 324.8 321.0
513.0 5649 -5.7 -29.7 13 0.64 125 10 323.6 326.0 323.8
500.0 5850 -5.1 -30.1 12 0.63 155 11 326.8 329.1 326.9
494.0 5945 -4.9 -29.9 12 0.65 146 11 328.1 330.6 328.3
471.7 6300 -7.4 -32.0 12 0.56 110 13 329.3 331.5 329.4
453.7 6600 -9.6 -33.8 12 0.49 100 14 330.3 332.2 330.4
400.0 7570 -16.5 -39.5 12 0.31 105 14 333.5 334.7 333.5
398.0 7607 -16.9 -39.9 12 0.30 104 14 333.4 334.6 333.5
371.9 8100 -20.4 -42.6 12 0.24 95 16 335.4 336.3 335.4
300.0 9660 -31.3 -51.3 12 0.11 115 18 341.1 341.6 341.2
269.0 10420 -36.3 -55.3 12 0.08 79 20 344.7 345.0 344.7
265.9 10500 -36.9 75 20 344.9 344.9
250.0 10920 -40.3 80 28 346.0 346.0
243.4 11100 -41.8 85 37 346.4 346.4
222.5 11700 -46.9 75 14 347.6 347.6
214.0 11960 -49.1 68 16 348.1 348.1
200.0 12400 -52.7 55 20 349.1 349.1
156.0 13953 -66.1 55 25 352.1 352.1
152.3 14100 -67.2 55 26 352.6 352.6
150.0 14190 -67.9 55 26 352.9 352.9
144.7 14400 -69.6 60 26 353.6 353.6
137.5 14700 -72.0 60 39 354.6 354.6
130.7 15000 -74.3 50 28 355.6 355.6
124.2 15300 -76.7 40 36 356.5 356.5
118.0 15600 -79.1 50 48 357.4 357.4
116.0 15698 -79.9 45 44 357.6 357.6
112.0 15900 -79.1 45 26 362.6 362.6
106.3 16200 -78.0 35 24 370.2 370.2
100.0 16550 -76.7 35 24 379.3 379.3
</PRE><H3>Station information and sounding indices</H3><PRE>
Station identifier: WIII
Station number: 96749
Observation time: 951002/0000
Station latitude: -6.11
Station longitude: 106.65
Station elevation: 8.0
Showalter index: 6.30
Lifted index: -1.91
LIFT computed using virtual temperature: -2.80
SWEAT index: 145.41
K index: 6.50
Cross totals index: 13.30
Vertical totals index: 23.30
Totals totals index: 36.60
Convective Available Potential Energy: 799.02
CAPE using virtual temperature: 1070.13
Convective Inhibition: -26.70
CINS using virtual temperature: -12.88
Equilibrum Level: 202.64
Equilibrum Level using virtual temperature: 202.60
Level of Free Convection: 828.70
LFCT using virtual temperature: 909.19
Bulk Richardson Number: 210.78
Bulk Richardson Number using CAPV: 282.30
Temp [K] of the Lifted Condensation Level: 294.96
Pres [hPa] of the Lifted Condensation Level: 958.67
Mean mixed layer potential temperature: 298.56
Mean mixed layer mixing ratio: 17.50
1000 hPa to 500 hPa thickness: 5752.00
Precipitable water [mm] for entire sounding: 36.31
</PRE>
<H2>96749 WIII Jakarta Observations at 00Z 03 Oct 1995</H2>
<PRE>
-----------------------------------------------------------------------------
PRES HGHT TEMP DWPT RELH MIXR DRCT SKNT THTA THTE THTV
hPa m C C % g/kg deg knot K K K
-----------------------------------------------------------------------------
1012.0 8 23.6 22.9 96 17.72 140 2 295.7 346.9 298.9
1000.0 107 24.0 21.6 86 16.54 135 3 297.1 345.2 300.1
990.0 195 24.4 20.3 78 15.39 128 4 298.4 343.4 301.2
945.4 600 22.9 20.2 85 16.00 95 7 300.9 348.0 303.7
925.0 791 22.2 20.1 88 16.29 100 6 302.0 350.3 304.9
913.5 900 21.9 18.2 80 14.63 105 6 302.8 346.3 305.4
911.0 924 21.8 17.8 78 14.28 108 6 302.9 345.4 305.5
850.0 1522 17.4 16.7 96 14.28 175 6 304.4 347.1 307.0
836.0 1665 16.4 16.4 100 14.24 157 7 304.8 347.5 307.4
811.0 1925 15.0 14.7 98 13.14 123 8 305.9 345.6 308.3
795.0 2095 14.2 7.2 63 8.08 101 9 306.8 331.6 308.3
794.5 2100 14.2 7.2 63 8.05 100 9 306.8 331.5 308.3
745.0 2642 10.4 2.4 58 6.14 64 11 308.4 327.6 309.6
736.0 2744 11.0 0.0 47 5.23 57 11 310.2 326.7 311.1
713.8 3000 9.2 5.0 75 7.70 40 12 310.9 335.0 312.4
711.0 3033 9.0 5.6 79 8.08 40 12 311.0 336.2 312.6
700.0 3163 8.6 1.6 61 6.18 40 12 312.0 331.5 313.1
688.5 3300 8.3 -6.0 36 3.57 60 12 313.1 324.8 313.8
678.0 3427 8.0 -13.0 21 2.08 70 12 314.2 321.2 314.6
642.0 3874 5.0 -2.0 61 5.17 108 11 315.7 332.4 316.7
633.0 3989 4.4 -11.6 30 2.50 117 10 316.3 324.7 316.8
616.6 4200 3.1 -14.1 27 2.09 135 10 317.1 324.3 317.6
580.0 4694 0.0 -20.0 21 1.36 164 13 319.1 323.9 319.4
572.3 4800 -0.4 -20.7 20 1.29 170 14 319.9 324.5 320.1
510.8 5700 -4.0 -26.6 15 0.86 80 10 326.1 329.2 326.2
500.0 5870 -4.7 -27.7 15 0.79 80 10 327.2 330.2 327.4
497.0 5917 -4.9 -27.9 15 0.78 71 13 327.6 330.5 327.7
491.7 6000 -5.5 -28.3 15 0.76 55 19 327.9 330.7 328.0
473.0 6300 -7.6 -29.9 15 0.68 55 16 328.9 331.4 329.0
436.0 6930 -12.1 -33.1 16 0.54 77 17 330.9 333.0 331.0
400.0 7580 -17.9 -37.9 16 0.37 100 19 331.6 333.1 331.7
388.3 7800 -19.9 -39.9 15 0.31 105 20 331.8 333.1 331.9
386.0 7844 -20.3 -40.3 15 0.30 103 20 331.9 333.1 331.9
372.0 8117 -18.3 -38.3 16 0.38 91 23 338.1 339.6 338.1
343.6 8700 -22.1 -41.4 16 0.30 65 29 340.7 342.0 340.8
329.0 9018 -24.1 -43.1 16 0.26 73 27 342.2 343.2 342.2
300.0 9680 -29.9 -44.9 22 0.23 90 22 343.1 344.1 343.2
278.6 10200 -34.3 85 37 344.1 344.1
266.9 10500 -36.8 60 32 344.7 344.7
255.8 10800 -39.4 65 27 345.2 345.2
250.0 10960 -40.7 65 27 345.4 345.4
204.0 12300 -51.8 55 23 348.6 348.6
200.0 12430 -52.9 55 23 348.8 348.8
194.6 12600 -55.0 60 23 348.1 348.1
160.7 13800 -70.1 35 39 342.4 342.4
153.2 14100 -73.9 35 41 340.6 340.6
150.0 14230 -75.5 35 41 339.9 339.9
131.5 15000 -76.3 50 53 351.6 351.6
124.9 15300 -76.6 50 57 356.2 356.2
122.0 15436 -76.7 57 45 358.3 358.3
118.6 15600 -77.3 65 31 360.2 360.2
115.0 15779 -77.9 65 31 362.2 362.2
112.6 15900 -77.7 85 17 364.8 364.8
107.0 16200 -77.2 130 10 371.2 371.2
100.0 16590 -76.5 120 18 379.7 379.7
</PRE><H3>Station information and sounding indices</H3><PRE>
Station identifier: WIII
Station number: 96749
Observation time: 951003/0000
Station latitude: -6.11
Station longitude: 106.65
Station elevation: 8.0
Showalter index: -0.58
Lifted index: 0.17
LIFT computed using virtual temperature: -0.57
SWEAT index: 222.41
K index: 31.80
Cross totals index: 21.40
Vertical totals index: 22.10
Totals totals index: 43.50
Convective Available Potential Energy: 268.43
CAPE using virtual temperature: 431.38
Convective Inhibition: -84.04
CINS using virtual temperature: -81.56
Equilibrum Level: 141.42
Equilibrum Level using virtual temperature: 141.35
Level of Free Convection: 784.91
LFCT using virtual temperature: 804.89
Bulk Richardson Number: 221.19
Bulk Richardson Number using CAPV: 355.46
Temp [K] of the Lifted Condensation Level: 293.21
Pres [hPa] of the Lifted Condensation Level: 940.03
Mean mixed layer potential temperature: 298.46
Mean mixed layer mixing ratio: 16.01
1000 hPa to 500 hPa thickness: 5763.00
Precipitable water [mm] for entire sounding: 44.54
这里是我的数据
这就是我想要的