Question

我有一个大数据（.tr文件）。我已经读取了文件并在数据框（df）中重命名了列。我设法查看了所有现有记录并检查了某些条件。我需要计算整个文件中存在多少个唯一值（来自src.port列）？以下MWE将说明我的问题。

# The df looks like:
     st time      from to protocol size flags    flowID src.port dst.port  seq   pktID
      + 0.100000    1   2      tcp   40 -------      1      5.0       2.1     0     0
      - 0.100000    5   0      ack   40 -------      1      5.1       2.3     0     0
      r 0.102032    1   2      tcp   40 -------      1      5.20      2.5     0     0
      r 0.102032    1   2      tcp   40 -------      1      5.11      2.6     0     0
      r 0.102032    1   2      tcp   40 -------      1      3.0       2.0     0     0
      + 0.121247   11   0      ack   40 -------      1      11.1      2.10    0     1
      r 0.132032    1   2      tcp   40 -------      1      3.0       2.0     0     0
      r 0.142065    1   2      tcp   40 -------      1      3.0       4.0     0     0

 # I have tried the following:
   unique<-0
  for (i in 1:nrow(df)){
    # feel free to suggest different way from the below line. 
    # I think using the name of column would be better 
    if(df[i,1]=="r" && df[i,3]== 1 && df[i,4]== 2 && df[i,5]== "tcp" ){
     # now this condition is my question
     # check if df[i,9] is new not presented before...Note 5.0 is different from 5.1 
     # check if df[i,10] is 2 and ignore any value after the dot (i.e 2.x ..X means any value)
     # so the condition would be:
      if ( df[i,9] is new not repeated && df[i,10] is 2.x)
          unique<-unique+1
     }

   }

从样本数据

预期输出：是唯一= 3

Answer 1

您可以简单地对相关数据进行分组，并使用unique。在这里，我将所有条件链接在一起并仅提取“scr.port”列并在结果上使用unique。

unique(mydf[mydf[, "st"] == "r" & 
              mydf[, "from"] == 1 & 
              mydf[, "protocol"] == "tcp" & 
              grepl("^2.*", mydf[, "dst.port"]), 
            "src.port"])
# [1] 5.20 5.11 3.00

在length中换行以获取您正在寻找的计数。

或者，创建数据的子集并计算行数。

out <- mydf[mydf[, "st"] == "r" & 
              mydf[, "from"] == 1 & 
              mydf[, "protocol"] == "tcp" & 
              grepl("^2.*", mydf[, "dst.port"]), ]
nrow(out[!duplicated(out$src.port), ])
# [1] 3

计算数据框内唯一数字的出现次数

1 个答案: