Question

我正在写一个R代码来计算我给定数据的每分钟数据点的平均值。

我的数据框是

2017-06-14 10:51:24,199 ERROR [qtp592179046-16] com.retailwave.rwos.compartment.rest.exception.RWCompartmentRestExceptionMapper - Exception caught at Mapper : Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.4.v20160829-44060b6): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLTransactionRollbackException: A lock could not be obtained within the time requested

我希望我的结果数据框有

TIME                              PRICE
2013-01-01 23:54:54               20133
2013-01-01 23:54:50               20133
2013-01-01 23:53:34               20134
2013-01-01 23:53:40               20131
2013-01-01 22:52:54               20131
2013-01-01 22:52:50               20132

我使用代码段将我的数据分成小时和分钟。

TIME                              PRICE
2013-01-01 23:54:00               20133
2013-01-01 23:53:00               20132.5
2013-01-01 23:52:00               20131.5

使用包trade_1[, c('Hour', 'Minute') := .(data.table::hour("TIME"), minute("TIME")) + ][, .(Avg = mean("PRICE")), .(Hour, Minute)]

我收到以下错误

lubridate

有人可以帮帮我吗？

我已使用Error in `:=`(c("Hour", "Minute"), .(data.table::hour("TRADETIME"), minute("TRADETIME"))) : could not find function ":="

Answer 1

我们需要转换为data.table并且不需要变量引用

library(data.table)
setDT(trade_1)[, c('Hour', 'Minute') := .(hour(TIME), minute(TIME))
        ][, .(Avg = mean(PRICE)), .(Hour, Minute)]
#   Hour Minute     Avg
#1:   23     54 20133.0
#2:   23     53 20132.5
#3:   22     52 20131.5

R“：=”中的未定义函数错误

1 个答案: