小编jpi*_*elo的帖子

我有一个df包含600多个变量的data.frame .我正在编写一个自动创建列的函数,需要对它们进行一次视觉检查.

该str功能提供了一个很好的总结:

str(df)
'data.frame':   29 obs. of  602 variables:
 $ uniqueSessionsIni: POSIXct, format: "2015-01-05 15:00:00" "2015-01-05 16:00:00" "2015-01-05 17:00:00" ...
 $ uniqueSessionsEnd: POSIXct, format: "2015-01-05 15:59:00" "2015-01-05 16:59:00" "2015-01-05 17:59:00" ...
 $ m0p0             : POSIXct, format: "2015-01-05 15:00:00" "2015-01-05 15:00:00" "2015-01-05 15:00:00" ...
 $ m1p0             : POSIXct, format: "2015-01-05 15:01:00" "2015-01-05 15:01:00" "2015-01-05 15:01:00" ...
 $ m2p0             : POSIXct, format: "2015-01-05 15:02:00" "2015-01-05 15:02:00" "2015-01-05 15:02:00" ...    

它继续...
但截断输出,如下所示:

$ m33p1            : POSIXct, format: "2015-01-05 …

想象一下数据框如下面的df1:

df1 <- data.frame(v1 = as.factor(c("m0p1", "m5p30", "m11p20", "m59p60", "m59p60")))

如何创建变量所有级别的列表？谢谢.

我可以成功使用foverlaps我的数据集的一小部分样本,但是当使用完整数据(data.tables超过30k行)时,它会崩溃并抛出以下错误:

错误信息:

Error in if (any(x[[xintervals[2L]]] - x[[xintervals[1L]]] < 0L)) stop("All entries in column ",  :
  missing value where TRUE/FALSE needed

我解释错误消息的方式是两个data.tables之间没有重叠.

Q1-Am我能很好地解释这个消息吗？

Q2 - 任何想法为什么这可能发生在更大的数据集上？这可能是由于数据集的大小造成的吗？

我确实有很多独特的值,根据foverlaps帮助文件,可以预期会按比例减慢速度,但不会在它进入数百万行之前,这远非如此.谢谢.

我试图在谷歌地图上绘制一个线层。

数据

> dput(map)
new("SpatialLinesDataFrame"
        , data = structure(list(att = c(463643, 2291491, 315237340, 10348934, 
309845150, 674351, 58057, 55962, 302861, 1405635)), .Names = "att",     row.names = c(NA, 
10L), class = "data.frame")
    , lines = list(<S4 object of class structure("Lines", package = "sp")>, 
    <S4 object of class structure("Lines", package = "sp")>, 
    <S4 object of class structure("Lines", package = "sp")>, 
    <S4 object of class structure("Lines", package = "sp")>, 
    <S4 object of class structure("Lines", package = "sp")>, 
    <S4 object of class structure("Lines", package = …

数据

v1 <- c("2015-01-05 15:00:00", "2015-01-05 15:45:00", "2015-01-05 15:00:30")

营运

v2 <- strptime(v1, '%Y-%m-%d %H:%M:%S')
str(v2)
POSIXlt[1:3], format: "2015-01-05 15:00:00" "2015-01-05 15:45:00" "2015-01-05 15:00:30"

v3 <- v2[!v2$min]  # create v3 from v2 eliminating min != 00

结果(成功的子集)

str(v3)
POSIXlt[1:2], format: "2015-01-05 15:00:00" "2015-01-05 15:00:30"

现在通过将v2强制转换为POSIXct来创建v4(成功)

v4 <- as.POSIXct(v2, format = "%y/%m/%d  %H:%M")

str(v4)
POSIXct[1:3], format: "2015-01-05 15:00:00" "2015-01-05 15:45:00" "2015-01-05 15:00:30"

问题中的操作 - 对POSIXct应用与POSIXlt相同的子集操作会导致下面的错误

v5 <- v4[!v4$min]  # reassign v2 eliminating min != 00

结果(错误)

  Error in v4$min : $ …