R语言学习——常见错误、原因及解决办法

R语⾔学习——常见错误、原因及解决办法
1、赋值时，只能对数据类型统⼀的变量赋
错误：对数据框中的变量进⾏条件赋值时，赋值失败，显⽰错误为：
Error in x[...] <- m : invalid subscript type 'builtin'
In addition: Warning message:
In `[<-.factor`(`*tmp*`, is.na, value = 0) :
invalid factor level, NA generated
原因：从excel中导⼊数据⾄数据框data.frame时，当⼀列变量中既有数字⼜有字符或逻辑值时，导⼊的变量数据类型会⾃动设置为因⼦factor，⽽factor类型的变量不能直接赋值，
解决办法：必须使⽤as.numeric( )，as.character( )等函数将变量的数据类型转换为“数值型”或“字符串”后，再进⾏赋值操作
另：对数据框中的多列变量数据批量转换数据格式时，可采⽤sapply和lapply函数联⽤的⽅式进⾏批量操作。

sapply函数输出的返回值是向量类型，可作为数据框的索引向量达到条件筛选的⽬的
lapply函数输出的返回值是数据框data.frame或列表list类型，可作为数据类型转换函数as.XX的嵌套函数，输出结果数据框
⽰例：
1、从剪切板中导⼊20⾏⽔质监测数据
wq <- read.table("clipboard",sep="\t",header=T)
此时查看wq数据集中的数据结构
> str(wq)
'data.frame': 20 obs. of 37 variables:
$ 测站名称: Factor w/ 20 levels "坝上（龙王庙）",..: 2 17 5 4 15 13 9 18 14 11 ...
$ 测站编码: int 99930128 99930133 99930129 99930130 99910136 99930134 99930131 99910124 99910126 99910125 ...
$ 垂线编号: int 1 1 1 1 1 1 1 1 1 1 ...
$ 层⾯编号: int 1 1 1 1 1 1 1 1 1 1 ...
$ ⽔体类型: int 1 1 1 1 3 1 3 1 1 NA ...
$ 采样时间: Factor w/ 1 level "2021/1/1 0:00": 1 1 1 1 1 1 1 1 1 1 ...
$ WT : num 10.2 11.4 11.9 12 8.2 11 11.9 5.6 4.5 6.9 ...
$ PH : num 8.2 7.7 7.7 7.7 8.1 7.7 7.6 8 8 8 ...
$ DOX : num 9.4 9.5 9.6 9.7 11.7 10.1 9.2 14.1 12.8 13.2 ...
$ CODMN : num 1.65 1.55 1.52 1.59 1.8 1.57 1.57 1.1 0.8 0.9 ...
$ CODCR : Factor w/ 14 levels "<2.3","2.5","2.6",..: 7 13 5 13 3 11 6 10 1 1 ...
$ BOD5 : Factor w/ 11 levels "<0.5","0.1","0.4",..: 1 1 1 1 8 3 2 8 7 6 ...
$ NH3N : Factor w/ 14 levels "<0.025","0.022",..: 2 6 4 10 3 10 13 1 1 1 ...
$ TP : Factor w/ 6 levels "<0.01","0.01",..: 1 1 1 2 3 1 1 5 4 3 ...
$ TN : num 1.03 1.05 1.09 1.08 1.04 1.15 1.44 3.91 1.8 2.24 ...
$ CU : Factor w/ 3 levels "<0.002","0.002",..: 1 1 1 1 1 1 1 3 2 2 ...
$ ZN : Factor w/ 11 levels "<0.0006","0.0006",..: 1 1 1 10 1 1 1 3 2 6 ...
$ F : num 0.15 0.21 0.13 0.19 0.13 0.19 0.2 0.19 0.13 0.12 ...
$ SE : Factor w/ 1 level "<0.00041": 1 1 1 1 1 1 1 1 1 1 ...
$ ARS : Factor w/ 13 levels "<0.00012","0.00016",..: 7 9 3 9 5 12 4 13 6 6 ...
$ HG : Factor w/ 1 level "<0.00001": 1 1 1 1 1 1 1 1 1 1 ...
$ CD : Factor w/ 1 level "<0.0005": 1 1 1 1 1 1 1 1 1 1 ...
$ CR6 : Factor w/ 1 level "<0.004": 1 1 1 1 1 1 1 1 1 1 ...
$ PB : Factor w/ 1 level "<0.004": 1 1 1 1 1 1 1 1 1 1 ...
$ CN : Factor w/ 1 level "<0.001": 1 1 1 1 1 1 1 1 1 1 ...
$ VLPH : Factor w/ 5 levels "<0.0003","0.0005",..: 1 1 1 1 1 1 1 4 2 3 ...
$ OIL : Factor w/ 1 level "<0.01": 1 1 1 1 1 1 1 1 1 1 ...
$ LAS : Factor w/ 1 level "<0.05": 1 1 1 1 1 1 1 1 1 1 ...
$ S2 : Factor w/ 1 level "<0.005": 1 1 1 1 1 1 1 1 1 1 ...
$ FCG : Factor w/ 14 levels "<10","10","100",..: 8 1 1 2 1 1 13 1 12 7 ...
$ SO4 : Factor w/ 16 levels "18.41","18.66",..: 14 6 1 13 11 7 10 16 16 16 ...
$ CL : Factor w/ 16 levels "2.79","2.83",..: 15 10 7 14 2 5 13 16 16 16 ...
$ NO3 : Factor w/ 14 levels "0.92","0.94",..: 4 2 2 2 1 5 10 14 14 14 ...
$ FE : Factor w/ 15 levels "0.0536","0.054",..: 2 5 3 1 4 5 7 15 15 15 ...
$ MN : Factor w/ 14 levels "0.002","0.0035",..: 2 6 3 4 1 2 12 14 14 14 ...
$ CLARITY : Factor w/ 13 levels "1","1.2","1.5",..: 9 10 11 12 6 12 8 13 13 13 ...
$ CHLA : Factor w/ 11 levels "0.39","1.13",..: 5 9 7 6 10 8 3 11 11 11 ...
可以看到数据框wq中有数值型，也有因⼦型变量
2、将监测数据中所有的“未监测”赋值为NA
因为wq中数据有因⼦factor类型，所以要想达到条件赋值的⽬的，要分两步⾛，⼀是修改数据类型，⼆是赋值（1）将数据集wq中的因⼦类型数据均转化为数值型
> wq[sapply(wq,is.factor)] <- lapply(wq[sapply(wq,is.factor)],as.character)
> str(wq)
'data.frame': 20 obs. of 37 variables:
$ 测站名称: chr "⽩渡滩" "⾹花镇张寨" "丹库中⼼" "仓房镇-赵沟" ...
$ 测站编码: int 99930128 99930133 99930129 99930130 99910136 99930134 99930131 99910124 99910126 99910125 ...
$ 垂线编号: int 1 1 1 1 1 1 1 1 1 1 ...
$ 层⾯编号: int 1 1 1 1 1 1 1 1 1 1 ...
$ ⽔体类型: int 1 1 1 1 3 1 3 1 1 NA ...
$ 采样时间: chr "2021/1/1 0:00" "2021/1/1 0:00" "2021/1/1 0:00" "2021/1/1 0:00" ...
$ WT : num 10.2 11.4 11.9 12 8.2 11 11.9 5.6 4.5 6.9 ...
$ PH : num 8.2 7.7 7.7 7.7 8.1 7.7 7.6 8 8 8 ...
$ DOX : num 9.4 9.5 9.6 9.7 11.7 10.1 9.2 14.1 12.8 13.2 ...
$ CODMN : num 1.65 1.55 1.52 1.59 1.8 1.57 1.57 1.1 0.8 0.9 ...
$ CODCR : chr "4.2" "7.2" "3.1" "7.2" ...
$ BOD5 : chr "<0.5" "<0.5" "<0.5" "<0.5" ...
$ NH3N : chr "0.022" "0.054" "0.045" "0.112" ...
$ TP : chr "<0.01" "<0.01" "<0.01" "0.01" ...
$ TN : num 1.03 1.05 1.09 1.08 1.04 1.15 1.44 3.91 1.8 2.24 ...
$ CU : chr "<0.002" "<0.002" "<0.002" "<0.002" ...
$ ZN : chr "<0.0006" "<0.0006" "<0.0006" "0.0028" ...
$ F : num 0.15 0.21 0.13 0.19 0.13 0.19 0.2 0.19 0.13 0.12 ...
$ SE : chr "<0.00041" "<0.00041" "<0.00041" "<0.00041" ...
$ ARS : chr "0.00041" "0.00049" "0.00027" "0.00049" ...
$ HG : chr "<0.00001" "<0.00001" "<0.00001" "<0.00001" ...
$ CD : chr "<0.0005" "<0.0005" "<0.0005" "<0.0005" ...
$ CR6 : chr "<0.004" "<0.004" "<0.004" "<0.004" ...
$ PB : chr "<0.004" "<0.004" "<0.004" "<0.004" ...
$ CN : chr "<0.001" "<0.001" "<0.001" "<0.001" ...
$ VLPH : chr "<0.0003" "<0.0003" "<0.0003" "<0.0003" ...
$ OIL : chr "<0.01" "<0.01" "<0.01" "<0.01" ...
$ LAS : chr "<0.05" "<0.05" "<0.05" "<0.05" ...
$ S2 : chr "<0.005" "<0.005" "<0.005" "<0.005" ...
$ FCG : chr "30" "<10" "<10" "10" ...
$ SO4 : chr "23.83" "20.27" "18.41" "22.69" ...
$ CL : chr "5.66" "3.66" "3.27" "4.31" ...
$ NO3 : chr "0.98" "0.94" "0.94" "0.94" ...
$ FE : chr "0.054" "0.0637" "0.0547" "0.0536" ...
$ MN : chr "0.0035" "0.0062" "0.0036" "0.0039" ...
$ CLARITY : chr "2.7" "3" "3.7" "4" ...
$ CHLA : chr "2.29" "3.05" "2.66" "2.32" ...
此时通过str( )函数看到wq数据框中的factor类型变量已经全部转换为character类型了
（2）进⾏条件赋值
> wq[wq=="未监测"]=NA
> wq
测站名称测站编码垂线编号层⾯编号⽔体类型采样时间 WT PH DOX CODMN CODCR BOD5
1 ⽩渡滩 99930128 1 1 1 2021/1/1 0:00 10.
2 8.2 9.4 1.65 4.2 <0.5
2 ⾹花镇张寨 9993013
3 1 1 1 2021/1/1 0:00 11.
4 7.7 9.
5 1.55 7.2 <0.5
3 丹库中⼼ 99930129 1 1 1 2021/1/1 0:00 11.9 7.7 9.6 1.52 3.1 <0.5
4 仓房镇-赵沟 99930130 1 1 1 2021/1/1 0:00 12.0 7.7 9.7 1.59 7.2 <0.5
5 陶岔 9991013
6 1 1 3 2021/1/1 0:00 8.2 8.1 11.
7 1.80 2.6 0.9
6 清泉沟 99930134 1 1 1 2021/1/1 0:00 11.0 7.
7 10.1 1.57 5.3 0.4
7 凉⽔河-台⼦⼭ 99930131 1 1 3 2021/1/1 0:00 11.9 7.6 9.2 1.57 4.1 0.1
8 湘河河⼝ 99910124 1 1 1 2021/1/1 0:00 5.6 8.0 14.1 1.10 5 0.9
9 滔河河⼝ 99910126 1 1 1 2021/1/1 0:00 4.5 8.0 12.8 0.80 <2.3 0.8
10 淇河河⼝ 99910125 1 1 NA 2021/1/1 0:00 6.9 8.0 13.2 0.90 <2.3 0.7
11 ⽼鹳河河⼝ 99910127 1 1 NA 2021/1/1 0:00 2.9 7.9 13.1 2.80 7.4 1
12 柳陂镇⼭跟前 99930108 1 1 NA 2021/1/1 0:00 9.1 7.9 9.5 1.49 <2.3 0.6
13 汉库中⼼ 99930109 1 1 NA 2021/1/1 0:00 9.5 8.0 9.3 1.42 3 <0.5
14 青⼭-安阳 99930112 1 1 NA 2021/1/1 0:00 9.8 7.6 9.6 1.44 2.5 1.1
15 远河河⼝ 99930114 1 1 NA 2021/1/1 0:00 10.5 7.6 9.4 1.79 <2.3 <0.5
16 武当⼭-三塘湾 99930117 1 1 NA 2021/1/1 0:00 12.2 7.6 9.3 1.76 <2.3 0.5
17 肖川-龙⼝ 99930118 1 1 NA 2021/1/1 0:00 11.7 7.6 9.0 1.88 5 1.6
18 浪河⼝下 99930121 1 1 NA 2021/1/1 0:00 12.2 7.6 9.1 1.81 5.6 <0.5
19 坝上（龙王庙） 99930123 1 1 NA 2021/1/1 0:00 12.2 7.5 7.8 1.88 4.4 <0.5
20 ⽩河河⼝（左） 99910102 1 1 NA 2021/1/1 0:00 8.4 8.2 13.4 1.50 4.7 0.8
NH3N TP TN CU ZN F SE ARS HG CD CR6 PB CN VLPH
1 0.02
2 <0.01 1.0
3 <0.002 <0.0006 0.15 <0.00041 0.00041 <0.00001 <0.0005 <0.00
4 <0.004 <0.001 <0.0003
2 0.054 <0.01 1.05 <0.002 <0.0006 0.21 <0.00041 0.00049 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
3 0.045 <0.01 1.09 <0.002 <0.0006 0.13 <0.00041 0.00027 <0.00001 <0.0005 <0.00
4 <0.004 <0.001 <0.0003
4 0.112 0.01 1.08 <0.002 0.0028 0.19 <0.00041 0.00049 <0.00001 <0.000
5 <0.004 <0.004 <0.001 <0.0003
5 0.04 0.02 1.04 <0.002 <0.000
6 0.13 <0.00041 0.00036 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
6 0.112 <0.01 1.15 <0.002 <0.0006 0.19 <0.00041 0.00095 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
7 0.141 <0.01 1.44 <0.002 <0.0006 0.20 <0.00041 0.00029 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
8 <0.025 0.04 3.91 0.003 0.0011 0.19 <0.00041 0.001 <0.00001 <0.0005 <0.004 <0.004 <0.001 0.001
9 <0.025 0.03 1.80 0.002 0.0006 0.13 <0.00041 0.0004 <0.00001 <0.0005 <0.004 <0.004 <0.001 0.0005
10 <0.025 0.02 2.24 0.002 0.0016 0.12 <0.00041 0.0004 <0.00001 <0.0005 <0.004 <0.004 <0.001 0.0006
11 0.118 0.08 5.94 0.003 0.002 0.17 <0.00041 0.0005 <0.00001 <0.0005 <0.004 <0.004 <0.001 0.0017
12 0.048 0.02 1.45 <0.002 0.0015 0.15 <0.00041 <0.00012 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
13 0.129 0.02 1.58 <0.002 <0.0006 0.18 <0.00041 <0.00012 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
14 0.1 0.02 1.46 <0.002 0.0022 0.14 <0.00041 <0.00012 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
15 0.06 0.02 1.44 <0.002 <0.0006 0.21 <0.00041 <0.00012 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
16 0.141 0.02 1.42 <0.002 <0.0006 0.13 <0.00041 <0.00012 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
17 0.118 0.01 1.42 <0.002 <0.0006 0.11 <0.00041 <0.00012 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
18 0.094 0.02 1.26 <0.002 0.0012 0.13 <0.00041 0.00016 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
19 0.1 0.01 1.06 <0.002 0.0021 0.17 <0.00041 0.00044 <0.00001 <0.0005 <0.004 <0.004 <0.001 <0.0003
20 0.163 0.04 1.50 0.002 0.0041 0.15 <0.00041 0.0007 <0.00001 <0.0005 <0.004 <0.004 <0.001 0.0005
OIL LAS S2 FCG SO4 CL NO3 FE MN CLARITY CHLA
1 <0.01 <0.05 <0.005 30 23.83 5.66 0.98 0.054 0.0035 2.7 2.29
2 <0.01 <0.05 <0.005 <10 20.27 3.66 0.94 0.0637 0.0062
3 3.05
3 <0.01 <0.05 <0.005 <10 18.41 3.27 0.9
4 0.0547 0.0036 3.7 2.66
4 <0.01 <0.0
5 <0.005 10 22.69 4.31 0.94 0.053
6 0.0039 4 2.32
5 <0.01 <0.05 <0.005 <10 21.63 2.83 0.92 0.0582 0.002 2 3.45
6 <0.01 <0.05 <0.005 <10 20.48 3.11 0.99 0.063
7 0.0035 4 2.71
7 <0.01 <0.05 <0.005 60 21.48 4.14 1.27 0.0828 0.0131 2.5 1.53
8 <0.01 <0.05 <0.005 <10 <NA> <NA> <NA> <NA> <NA> <NA> <NA>
9 <0.01 <0.05 <0.005 52 <NA> <NA> <NA> <NA> <NA> <NA> <NA>
10 <0.01 <0.05 <0.005 20 <NA> <NA> <NA> <NA> <NA> <NA> <NA>
11 <0.01 <0.05 <0.005 390 <NA> <NA> <NA> <NA> <NA> <NA> <NA>
12 <0.01 <0.05 <0.005 40 18.95 3.69 1.3 0.067 0.0119 2.5 2.32
13 <0.01 <0.05 <0.005 110 18.66 2.86 1.39 0.1099 0.0119 2.1 2.09
14 <0.01 <0.05 <0.005 160 20.24 3.44 1.32 0.1335 0.009 1.5 1.53
15 <0.01 <0.05 <0.005 80 26.38 2.79 1.2 0.1434 0.0162 1.8 1.53
16 <0.01 <0.05 <0.005 <10 21.28 3.21 1.19 0.167 0.0081 1.2 0.39
17 <0.01 <0.05 <0.005 100 18.85 3.89 1.24 0.1158 0.0045 1.5 1.13
18 <0.01 <0.05 <0.005 40 20.52 3.28 1.13 0.1415 0.0078 1 1.13
19 <0.01 <0.05 <0.005 190 22.07 2.84 0.97 0.1034 0.0122 1.7 1.13
20 <0.01 <0.05 <0.005 380 <NA> <NA> <NA> <NA> <NA> <NA> <NA>
　可以看到，所有“未监测”已经变为NA，不放⼼可以再做⼀个判断
> is.na(wq)
测站名称测站编码垂线编号层⾯编号⽔体类型采样时间 WT PH DOX CODMN CODCR BOD5 NH3N
[1,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[2,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[3,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[4,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[5,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[6,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[7,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[8,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[9,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [10,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [11,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [12,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [13,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [14,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [15,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [16,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [17,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [18,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [19,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [20,] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
TP TN CU ZN F SE ARS HG CD CR6 PB CN VLPH OIL LAS S2
[1,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [2,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [3,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [4,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [5,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [6,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [7,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [8,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [9,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [10,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [11,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [12,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [13,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [14,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [15,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [16,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [17,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [18,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [19,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [20,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FCG SO4 CL NO3 FE MN CLARITY CHLA
[1,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[2,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[3,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[4,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[5,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[6,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[7,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[8,] FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
[9,] FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
[10,] FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
[11,] FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
[12,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[13,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[14,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[15,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[16,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[17,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[18,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[19,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[20,] FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
3、处理⼩于检出限（即形如：“<XX”）的数据，将此类数据全部替换为0
采⽤sapply（）函数联⽤gsub（）函数，批量替换⽂本
sapply（）函数起循环遍历的作⽤，可以得到结构更为简单的向量vector或矩阵matrix数据集合gsub（）函数是正则表达式⼤礼包中⽤于替换所有向量中⽂本的函数，⽤于构造条件替换
> sapply(wq,gsub,pattern="<[0-9]+.?[0-9]+",replacement=0)
测站名称测站编码垂线编号层⾯编号⽔体类型采样时间 WT PH DOX CODMN
[1,] "⽩渡滩" "99930128" "1" "1" "1" "2021/1/1 0:00" "10.2" "8.2" "9.4" "1.65"
[2,] "⾹花镇张寨" "99930133" "1" "1" "1" "2021/1/1 0:00" "11.4" "7.7" "9.5" "1.55"
[3,] "丹库中⼼" "99930129" "1" "1" "1" "2021/1/1 0:00" "11.9" "7.7" "9.6" "1.52"
[4,] "仓房镇-赵沟" "99930130" "1" "1" "1" "2021/1/1 0:00" "12" "7.7" "9.7" "1.59"
[5,] "陶岔" "99910136" "1" "1" "3" "2021/1/1 0:00" "8.2" "8.1" "11.7" "1.8"
[6,] "清泉沟" "99930134" "1" "1" "1" "2021/1/1 0:00" "11" "7.7" "10.1" "1.57"
[7,] "凉⽔河-台⼦⼭" "99930131" "1" "1" "3" "2021/1/1 0:00" "11.9" "7.6" "9.2" "1.57"
[8,] "湘河河⼝" "99910124" "1" "1" "1" "2021/1/1 0:00" "5.6" "8" "14.1" "1.1"
[9,] "滔河河⼝" "99910126" "1" "1" "1" "2021/1/1 0:00" "4.5" "8" "12.8" "0.8"
[10,] "淇河河⼝" "99910125" "1" "1" NA "2021/1/1 0:00" "6.9" "8" "13.2" "0.9"
[11,] "⽼鹳河河⼝" "99910127" "1" "1" NA "2021/1/1 0:00" "2.9" "7.9" "13.1" "2.8"
[12,] "柳陂镇⼭跟前" "99930108" "1" "1" NA "2021/1/1 0:00" "9.1" "7.9" "9.5" "1.49"
[13,] "汉库中⼼" "99930109" "1" "1" NA "2021/1/1 0:00" "9.5" "8" "9.3" "1.42"
[14,] "青⼭-安阳" "99930112" "1" "1" NA "2021/1/1 0:00" "9.8" "7.6" "9.6" "1.44"
[15,] "远河河⼝" "99930114" "1" "1" NA "2021/1/1 0:00" "10.5" "7.6" "9.4" "1.79"
[16,] "武当⼭-三塘湾" "99930117" "1" "1" NA "2021/1/1 0:00" "12.2" "7.6" "9.3" "1.76"
[17,] "肖川-龙⼝" "99930118" "1" "1" NA "2021/1/1 0:00" "11.7" "7.6" "9" "1.88"
[18,] "浪河⼝下" "99930121" "1" "1" NA "2021/1/1 0:00" "12.2" "7.6" "9.1" "1.81"
[19,] "坝上（龙王庙）" "99930123" "1" "1" NA "2021/1/1 0:00" "12.2" "7.5" "7.8" "1.88"
[20,] "⽩河河⼝（左）" "99910102" "1" "1" NA "2021/1/1 0:00" "8.4" "8.2" "13.4" "1.5"
CODCR BOD5 NH3N TP TN CU ZN F SE ARS HG CD CR6 PB CN
[1,] "4.2" "0" "0.022" "0" "1.03" "0" "0" "0.15" "0" "0.00041" "0" "0" "0" "0" "0"
[2,] "7.2" "0" "0.054" "0" "1.05" "0" "0" "0.21" "0" "0.00049" "0" "0" "0" "0" "0"
[3,] "3.1" "0" "0.045" "0" "1.09" "0" "0" "0.13" "0" "0.00027" "0" "0" "0" "0" "0"
[4,] "7.2" "0" "0.112" "0.01" "1.08" "0" "0.0028" "0.19" "0" "0.00049" "0" "0" "0" "0" "0"
[5,] "2.6" "0.9" "0.04" "0.02" "1.04" "0" "0" "0.13" "0" "0.00036" "0" "0" "0" "0" "0"
[6,] "5.3" "0.4" "0.112" "0" "1.15" "0" "0" "0.19" "0" "0.00095" "0" "0" "0" "0" "0"
[7,] "4.1" "0.1" "0.141" "0" "1.44" "0" "0" "0.2" "0" "0.00029" "0" "0" "0" "0" "0"
[8,] "5" "0.9" "0" "0.04" "3.91" "0.003" "0.0011" "0.19" "0" "0.001" "0" "0" "0" "0" "0"
[9,] "0" "0.8" "0" "0.03" "1.8" "0.002" "0.0006" "0.13" "0" "0.0004" "0" "0" "0" "0" "0"
[10,] "0" "0.7" "0" "0.02" "2.24" "0.002" "0.0016" "0.12" "0" "0.0004" "0" "0" "0" "0" "0"
[11,] "7.4" "1" "0.118" "0.08" "5.94" "0.003" "0.002" "0.17" "0" "0.0005" "0" "0" "0" "0" "0"
[12,] "0" "0.6" "0.048" "0.02" "1.45" "0" "0.0015" "0.15" "0" "0" "0" "0" "0" "0" "0"
[13,] "3" "0" "0.129" "0.02" "1.58" "0" "0" "0.18" "0" "0" "0" "0" "0" "0" "0"
[14,] "2.5" "1.1" "0.1" "0.02" "1.46" "0" "0.0022" "0.14" "0" "0" "0" "0" "0" "0" "0"
[15,] "0" "0" "0.06" "0.02" "1.44" "0" "0" "0.21" "0" "0" "0" "0" "0" "0" "0"
[16,] "0" "0.5" "0.141" "0.02" "1.42" "0" "0" "0.13" "0" "0" "0" "0" "0" "0" "0"
[17,] "5" "1.6" "0.118" "0.01" "1.42" "0" "0" "0.11" "0" "0" "0" "0" "0" "0" "0"
[18,] "5.6" "0" "0.094" "0.02" "1.26" "0" "0.0012" "0.13" "0" "0.00016" "0" "0" "0" "0" "0"
[19,] "4.4" "0" "0.1" "0.01" "1.06" "0" "0.0021" "0.17" "0" "0.00044" "0" "0" "0" "0" "0"
[20,] "4.7" "0.8" "0.163" "0.04" "1.5" "0.002" "0.0041" "0.15" "0" "0.0007" "0" "0" "0" "0" "0"
VLPH OIL LAS S2 FCG SO4 CL NO3 FE MN CLARITY CHLA
[1,] "0" "0" "0" "0" "30" "23.83" "5.66" "0.98" "0.054" "0.0035" "2.7" "2.29"
[2,] "0" "0" "0" "0" "0" "20.27" "3.66" "0.94" "0.0637" "0.0062" "3" "3.05"
[3,] "0" "0" "0" "0" "0" "18.41" "3.27" "0.94" "0.0547" "0.0036" "3.7" "2.66"
[4,] "0" "0" "0" "0" "10" "22.69" "4.31" "0.94" "0.0536" "0.0039" "4" "2.32"
[5,] "0" "0" "0" "0" "0" "21.63" "2.83" "0.92" "0.0582" "0.002" "2" "3.45"
[6,] "0" "0" "0" "0" "0" "20.48" "3.11" "0.99" "0.0637" "0.0035" "4" "2.71"
[7,] "0" "0" "0" "0" "60" "21.48" "4.14" "1.27" "0.0828" "0.0131" "2.5" "1.53"
[8,] "0.001" "0" "0" "0" "0" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测"
[9,] "0.0005" "0" "0" "0" "52" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测"
[10,] "0.0006" "0" "0" "0" "20" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测"
[11,] "0.0017" "0" "0" "0" "390" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测" "未监测"
[12,] "0" "0" "0" "0" "40" "18.95" "3.69" "1.3" "0.067" "0.0119" "2.5" "2.32"
[13,] "0" "0" "0" "0" "110" "18.66" "2.86" "1.39" "0.1099" "0.0119" "2.1" "2.09"
[14,] "0" "0" "0" "0" "160" "20.24" "3.44" "1.32" "0.1335" "0.009" "1.5" "1.53"。