R中的段错误使用reshape2包和dcast [英] segfault in R using reshape2 package and dcast

问题描述

当我尝试使用 dcast(来自 reshape2 包)重塑特定数据框时，RStudio 崩溃了.我发现崩溃实际上是在 R 本身中发生的，所以我在 R.app 中运行了我的强制转换代码，并得到了为该站点命名的错误类型:Error: segfault from C stack overflow.在 Google 和 SO 的帮助下，我了解到这是一个内存访问错误.

RStudio was crashing when I tried to reshape a particular data frame using dcast (from the reshape2 package). I discovered that the crash was actually happening in R itself, so I ran my casting code in R.app and got the type of error that gives this site its name: Error: segfault from C stack overflow. With the help of Google and SO, I learned that this is a memory access error.

好的，我已经做到了，但我不知道从这里去哪里.我无法提供一个真正可重现的示例，因为我的数据框大约有 558,000 行，并且在小型玩具示例上不会出现问题.例如，即使我采用 50,000 行的数据子集，dcast 也能正常工作.是否存在导致问题的特定数据行?如果是这样，任何人都可以建议寻找哪些功能可能导致我遇到的错误类型?

Okay, I got that far, but I don't know where to go from here. I can't provide a true reproducible example, because my data frame is about 558,000 rows and the problem doesn't occur on small toy examples. For example, even if I take, say, a 50,000-row subset of the data, dcast works just fine. Could there be a particular row of data that's causing a problem? If so, can anyone suggest what feature(s) to look for that could be causing the type of error I'm getting?

这是我从中转换的数据框的一个子集(一些变量的假值)，然后是我正在使用的转换函数.我还在下面的 dput 函数中包含了这个小数据片段，以防万一使用它会有所帮助.真实数据集有大约700个prog值，15个prog1值，5个fa.type值.

Here is a subset of the data frame I'm casting from (with fake values for some variables), followed by the casting function I'm using. I've also included this small snippet of data in a dput function below, in case it would be helpful to play around with it. The real data set has about 700 values of prog, 15 values of prog1, and 5 values of fa.type.

  id        term   yr    nslds acad.lev    prog            prog1 fa.type amount
1  1   Fall 2009 2010 Graduate Graduate  loan 1      Other Loans    Loan   5000
2  1 Spring 2010 2010 Graduate Graduate  loan 1      Other Loans    Loan   5000
3  2   Fall 2009 2010 Graduate Graduate  loan 2    Stafford Loan    Loan   8781
4  2 Spring 2010 2010 Graduate Graduate  loan 2    Stafford Loan    Loan   8781
5  3   Fall 2007 2008 Graduate Graduate  loan 3    Stafford Loan    Loan   4250
6  3   Fall 2007 2008 Graduate Graduate grant 1 University Grant   Grant   1707

fa.wide = dcast(id + term + yr + nslds + acad.lev ~ prog1 + fa.type , data=fa, value.var="amount", fun.aggregate=sum)

fa = structure(list(id = c(1, 1, 2, 2, 3, 3), term = structure(c(7L, 
8L, 7L, 8L, 1L, 1L), .Label = c("Fall 2007", "Spring 2008", "Summer 2008", 
"Fall 2008", "Spring 2009", "Summer 2009", "Fall 2009", "Spring 2010", 
"Summer 2010", "Fall 2010", "Spring 2011", "Summer 2011", "Fall 2011", 
"Spring 2012", "Summer 2012", "Fall 2012", "Spring 2013"), class = c("ordered", 
"factor")), yr = c(2010L, 2010L, 2010L, 2010L, 2008L, 2008L), 
    nslds = structure(c(7L, 7L, 7L, 7L, 7L, 7L), .Label = c("1st Year, Never Attended", 
    "1st Year, Previously Attended", "2nd Year", "3rd Year", 
    "4th Year", "5th Year+", "Graduate"), class = c("ordered", 
    "factor")), acad.lev = structure(c(6L, 6L, 6L, 6L, 6L, 6L
    ), .Label = c("Freshman", "Sophomore", "Junior", "Senior", 
    "PB Undergrad", "Graduate"), class = c("ordered", "factor"
    )), prog = c("loan 1", "loan 1", "loan 2", "loan 2", "loan 3", 
    "grant 1"), prog1 = c("Other Loans", "Other Loans", "Stafford Loan", 
    "Stafford Loan", "Stafford Loan", "University Grant"), fa.type = structure(c(3L, 
    3L, 3L, 3L, 3L, 2L), .Label = c("Athletic", "Grant", "Loan", 
    "Scholarship", "Waiver", "Work/Study"), class = "factor"), 
    amount = c(5000, 5000, 8781, 8781, 4250, 1707)), .Names = c("id", 
"term", "yr", "nslds", "acad.lev", "prog", "prog1", "fa.type", 
"amount"), row.names = c(NA, 6L), class = "data.frame")

推荐答案

只是为了结束这个老问题，这是一个已修复的错误，如 这个 github 问题.

Just to close out this old question, this was a bug that was fixed as described in this github issue.

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