PROSAGA码农传奇-场景模型-发现数据集样本之间的依赖关系

发现数据集样本之间的依赖关系

作者: 生如夏花
发布时间: 2024-04-22 03:53:21 (3月前)
转自：

<div class =“post-text”itemprop =“text”>
  <P>
    这是一个data.table的解决方案
  </p>
   <pre>
    <code>
      library(data.table)
dt <- data.table(ID=c(1,1,2,3,2,1,4,4,3,4),Activity=c("a","b","a","c","a","c","a","b","b","c"))

</code>
  </pre>
  <OL>
    <LI>
      <P>
        每个序列的ID：
      </p>
       <pre>
        <code>
          dt[,.(seq=paste(Activity,collapse = ",")),ID][,.(ids=paste(ID,collapse = ",")),seq]

</code>
      </pre>
    </LI>
    <LI>
      <P>
        我们可以得到一个快速的答案：
      </p>
       <pre>
        <code>
          consecutive_id <- dt[,.(first=(Activity),second=(shift(Activity,type = "lead"))),ID][!is.na(second)]
consecutive <- consecutive_id[,.N,.(first,second)]

</code>
      </pre>
      <P>
        但如果您需要在矩阵形式中需要一些额外的步骤：
      </p>
       <pre>
        <code>
          classes <- dt[,unique(Activity)];n <- length(classes)
M_consecutive <- data.table(matrix(0,nrow = n,ncol=n))
setnames(M_consecutive,classes)
M_consecutive$classes <- classes; setkey(M_consecutive,classes)
for(i in 1:nrow(consecutive)) M_consecutive[consecutive[i]$first,(consecutive[i]$second):=consecutive[i]$N]
M_consecutive

</code>
      </pre>
    </LI>
  </醇>
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