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rapache-spark-sqlsparkr

Error in mySparkDF.show() : could not find function "mySparkDF.show"


I'm want to start working with sparkR followed tutorials but I get the below error:

library(SparkR)
Sys.setenv(SPARK_HOME="/Users/myuserhone/dev/spark-2.2.0-bin-hadoop2.7")
  .libPaths(c(file.path(Sys.getenv("SPARK_HOME"),"R","lib"), .libPaths()))

spark <- sparkR.session(appName = "mysparkr", Sys.getenv("SPARK_HOME"), master = "local[*]")

csvPath <- "file:///Users/myuserhome/dev/spark-data/donation"
mySparkDF <- read.df(csvPath, "csv", header = "true", inferSchema = "true", na.strings = "?")
mySparkDF.show()

But I get:

Error in mySparkDF.show() : could not find function "mySparkDF.show"

Not sure what I do wrong, in addition, I don't have code completion for the spark functions like read.df(...)

In addition if I try

show(describe(mySparkDF))

or

show(summary(mySparkDF))

I get in results the metadata and not the "describe" expected result

SparkDataFrame[summary:string, id_1:string, id_2:string, cmp_fname_c1:string, cmp_fname_c2:string, cmp_lname_c1:string, cmp_lname_c2:string, cmp_sex:string, cmp_bd:string, cmp_bm:string, cmp_by:string, cmp_plz:string]

Anything i'm doing wrong?


Solution

  • show is not used in such a way in SparkR, neither it serves the same purpose with the same-name command in PySpark; you should use either head or showDF:

    df <- as.DataFrame(faithful)
    
    show(df)
    # result:
    SparkDataFrame[eruptions:double, waiting:double]
    
    head(df)
    # result:
       eruptions waiting
     1     3.600      79
     2     1.800      54
     3     3.333      74
     4     2.283      62
     5     4.533      85
     6     2.883      55
    
    showDF(df)
    # result:
    +---------+-------+
    |eruptions|waiting|
    +---------+-------+
    |      3.6|   79.0|
    |      1.8|   54.0|
    |    3.333|   74.0|
    |    2.283|   62.0|
    |    4.533|   85.0|
    |    2.883|   55.0|
    |      4.7|   88.0|
    |      3.6|   85.0|
    |     1.95|   51.0|
    |     4.35|   85.0|
    |    1.833|   54.0|
    |    3.917|   84.0|
    |      4.2|   78.0|
    |     1.75|   47.0|
    |      4.7|   83.0|
    |    2.167|   52.0|
    |     1.75|   62.0|
    |      4.8|   84.0|
    |      1.6|   52.0|
    |     4.25|   79.0|
    +---------+-------+
    only showing top 20 rows