[英]Aggregating the standard deviation and counting non-NAs in sparklyr
我有一個很大的 data.frame 並且我一直在使用summarise
和across
summarise
眾多變量的匯總統計信息。 由於我的 data.frame 的大小,我不得不開始在sparklyr
處理我的數據。
由於sparklyr
不支持across
我使用summarise_each
。 這是工作正常,但summarise_each
在sparklyr
似乎並不支持sd
和sum(!is.na(.))
下面是一個示例數據集以及我通常如何使用dplyr
處理它:
test <- data.frame(ID = c("Group1","Group1",'Group1','Group1','Group1','Group1','Group1',
"Group2","Group2","Group2",'Group2','Group2','Group2',"Group2",
"Group3","Group3","Group3"),
Value1 = c(-100,-10,-5,-5,-5,1,2,1,2,3,4,4,4,4,1,2,3),
Value2 = c(50,100,10,-5,3,1,2,2,2,3,4,4,4,4,1,2,3))
test %>%
group_by %>%
summarise(across((Value1:Value2), ~sum(!is.na(.), na.rm = TRUE), .names = "{col}_count"),
across((Value1:Value2), ~min(., na.rm = TRUE), .names = "{col}_min"),
across((Value1:Value2), ~max(., na.rm = TRUE), .names = "{col}_max"),
across((Value1:Value2), ~mean(., na.rm = TRUE), .names = "{col}_mean"),
across((Value1:Value2), ~sd(., na.rm = TRUE), .names = "{col}_sd"))
# A tibble: 1 x 10
Value1_count Value2_count Value1_min Value2_min Value1_max Value2_max Value1_mean Value2_mean Value1_sd Value2_sd
<int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 17 17 -100 -5 4 100 -5.53 11.2 24.7 25.8
我也能夠使用 summarise_each 成功獲得相同的答案,如下所示:
test %>%
group_by(ID) %>%
summarise_each(funs(min = min(., na.rm = TRUE),
max = max(., na.rm = TRUE),
mean = mean(., na.rm = TRUE),
sum = sum(., na.rm = TRUE),
sd = sd(., na.rm = TRUE)))
ID Value1_min Value2_min Value1_max Value2_max Value1_mean Value2_mean Value1_sum Value2_sum
<fct> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Group1 -100 -5 2 100 -17.4 23 -122 161
2 Group2 1 2 4 4 3.14 3.29 22 23
3 Group3 1 1 3 3 2 2 6 6
使用sparklyr
我已經成功地計算出min
、 max
、 mean
、 sum
,如下所示:
sc <- spark_connect(master = "local", version = "2.4.3")
test <- spark_read_csv(sc = sc, path = "C:\\path\\test space.csv")
test %>%
group_by(ID) %>%
summarise_each(funs(min = min(., na.rm = TRUE),
max = max(., na.rm = TRUE),
mean = mean(., na.rm = TRUE),
sum = sum(., na.rm = TRUE)))
# Source: spark<?> [?? x 9]
ID Value1_min Value_2_min Value1_max Value_2_max Value1_mean Value_2_mean Value1_sum Value_2_sum
<chr> <int> <int> <int> <int> <dbl> <dbl> <dbl> <dbl>
1 Group2 1 2 4 4 3.14 3.29 22 23
2 Group3 1 1 3 3 2 2 6 6
3 Group1 -100 -5 2 100 -17.4 23 -122 161
但是在嘗試獲取sd
和sum(!is.na(.))
時我收到錯誤消息下面是我收到的代碼和錯誤消息。 是否有任何解決方法可以幫助匯總這些值?
test %>%
group_by(ID) %>%
summarise_each(funs(min = min(., na.rm = TRUE),
max = max(., na.rm = TRUE),
mean = mean(., na.rm = TRUE),
sum = sum(., na.rm = TRUE),
sd = sd(., na.rm = TRUE)))
Error: org.apache.spark.sql.catalyst.parser.ParseException:
mismatched input 'AS' expecting ')'(line 1, pos 298)
== SQL ==
SELECT `ID`, MIN(`Value1`) AS `Value1_min`, MIN(`Value_2`) AS `Value_2_min`, MAX(`Value1`) AS `Value1_max`, MAX(`Value_2`) AS `Value_2_max`, AVG(`Value1`) AS `Value1_mean`, AVG(`Value_2`) AS `Value_2_mean`, SUM(`Value1`) AS `Value1_sum`, SUM(`Value_2`) AS `Value_2_sum`, stddev_samp(`Value1`, TRUE AS `na.rm`) AS `Value1_sd`, stddev_samp(`Value_2`, TRUE AS `na.rm`) AS `Value_2_sd`
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------^^^
FROM `test_space_30172a44_c0aa_4305_9a5e_d45fa77ba0b9`
GROUP BY `ID`
at org.apache.spark.sql.catalyst.parser.ParseException.withCommand(ParseDriver.scala:241)
at org.apache.spark.sql.catalyst.parser.AbstractSqlParser.parse(ParseDriver.scala:117)
at org.apache.spark.sql.execution.SparkSqlParser.parse(SparkSqlParser.scala:48)
at org.apache.spark.sql.catalyst.parser.AbstractSqlParser.parsePlan(ParseDriver.scala:69)
at org.apache.spark.sql.SparkSession.sql(SparkSession.scala:642)
at sun.reflect.GeneratedMethodAccessor66.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sparklyr.Invoke.invoke(invoke.scala:147)
at sparklyr.StreamHandler.handleMethodCall(stream.scala:136)
at sparklyr.StreamHandler.read(stream.scala:61)
at sparklyr.BackendHandler$$anonfun$channelRead0$1.apply$mcV$sp(handler.scala:58)
at scala.util.control.Breaks.breakable(Breaks.scala:38)
at sparklyr.BackendHandler.channelRead0(handler.scala:38)
at sparklyr.BackendHandler.channelRead0(handler.scala:14)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:284)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:138)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
at java.lang.Thread.run(Thread.java:748)
In addition: Warning messages:
1: Named arguments ignored for SQL stddev_samp
2: Named arguments ignored for SQL stddev_samp
問題是na.rm
參數。 Spark 的stddev_samp
函數沒有這樣的參數,而sparklyr
似乎沒有處理它。
SQL 中總是會刪除缺失值,因此您無需指定na.rm
。
test_spark %>%
group_by(ID) %>%
summarise_each(funs(min = min(.),
max = max(.),
mean = mean(.),
sum = sum(.),
sd = sd(.)))
#> # Source: spark<?> [?? x 11]
#> ID Value1_min Value2_min Value1_max Value2_max Value1_mean Value2_mean
#> <chr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 Group2 1 2 4 4 3.14 3.29
#> 2 Group1 -100 -5 2 100 -17.4 23
#> 3 Group3 1 1 3 3 2 2
#> Value1_sum Value2_sum Value1_sd Value2_sd
#> <dbl> <dbl> <dbl> <dbl>
#> 1 22 23 1.21 0.951
#> 2 -122 161 36.6 38.6
#> 3 6 6 1 1
這看起來像是一個特定於summarise
的錯誤,因為sd
與na.rm
與mutate
na.rm
工作正常。
test_spark %>%
group_by(ID) %>%
mutate_each(funs(sd = sd(., na.rm = TRUE)))
對於sum(!is.na(.))
,您只需將其寫為sum(ifelse(is.na(.), 0, 1))
。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.