Bug causes warning in h2o.group_by

[exalate-issue-sync]

This issue is present in the documentation for h2o.group_by:
https://docs.h2o.ai/h2o/latest-stable/h2o-docs/data-munging/groupby.html

A warning pops up in the second to last example, but that is because the function is doing an if on what it expects is a single column/logical, but several can be passed in, so it only checks the first.

I would expect a small amount of logic cleanup could resolve this confusion.

{code:r}

library(data.table)
data.table 1.14.2 using 4 threads (see ?getDTthreads). Latest news: r-datatable.com
library(h2o)

---

Your next step is to start H2O:
> h2o.init()

For H2O package documentation, ask for help:
> ??h2o

After starting H2O, you can use the Web UI at http://localhost:54321
For more information visit https://docs.h2o.ai

---

Attaching package: ‘h2o’

The following objects are masked from ‘package:data.table’:

hour, month, week, year

The following objects are masked from ‘package:stats’:

cor, sd, var

The following objects are masked from ‘package:base’:

%*%, %in%, &&, ||, apply, as.factor, as.numeric, colnames, colnames<-, ifelse, is.character, is.factor, is.numeric, log, log10, log1p, log2, round,
signif, trunc

devtools::session_info()

• Session info ----------------------------------------------------------------------------------------------------------------------------------------------------------
  setting value
  version R version 4.1.2 (2021-11-01)
  os Windows 10 x64 (build 22000)
  system x86_64, mingw32
  ui RStudio
  language (EN)
  collate English_United States.1252
  ctype English_United States.1252
  tz America/Chicago
  date 2022-01-08
  rstudio 2021.09.0+351 Ghost Orchid (desktop)
  pandoc NA

• Packages --------------------------------------------------------------------------------------------------------------------------------------------------------------
  package * version date (UTC) lib source
  bitops 1.0-7 2021-04-24 [1] CRAN (R 4.1.1)
  cachem 1.0.6 2021-08-19 [1] CRAN (R 4.1.2)
  callr 3.7.0 2021-04-20 [1] CRAN (R 4.1.2)
  cli 3.1.0 2021-10-27 [1] CRAN (R 4.1.2)
  crayon 1.4.2 2021-10-29 [1] CRAN (R 4.1.2)
  data.table * 1.14.2 2021-09-27 [1] CRAN (R 4.1.1)
  desc 1.4.0 2021-09-28 [1] CRAN (R 4.1.2)
  devtools 2.4.3 2021-11-30 [1] CRAN (R 4.1.2)
  ellipsis 0.3.2 2021-04-29 [1] CRAN (R 4.1.1)
  fastmap 1.1.0 2021-01-25 [1] CRAN (R 4.1.2)
  fs 1.5.2 2021-12-08 [1] CRAN (R 4.1.2)
  glue 1.6.0 2021-12-17 [1] CRAN (R 4.1.2)
  h2o * 3.36.0.1 2022-01-04 [1] CRAN (R 4.1.2)
  jsonlite 1.7.2 2020-12-09 [1] CRAN (R 4.1.1)
  lifecycle 1.0.1 2021-09-24 [1] CRAN (R 4.1.1)
  magrittr 2.0.1 2020-11-17 [1] CRAN (R 4.1.1)
  memoise 2.0.1 2021-11-26 [1] CRAN (R 4.1.2)
  pkgbuild 1.3.1 2021-12-20 [1] CRAN (R 4.1.2)
  pkgload 1.2.4 2021-11-30 [1] CRAN (R 4.1.2)
  prettyunits 1.1.1 2020-01-24 [1] CRAN (R 4.1.2)
  processx 3.5.2 2021-04-30 [1] CRAN (R 4.1.2)
  ps 1.6.0 2021-02-28 [1] CRAN (R 4.1.2)
  purrr 0.3.4 2020-04-17 [1] CRAN (R 4.1.1)
  R6 2.5.1 2021-08-19 [1] CRAN (R 4.1.1)
  RCurl 1.98-1.5 2021-09-17 [1] CRAN (R 4.1.1)
  remotes 2.4.2 2021-11-30 [1] CRAN (R 4.1.2)
  rlang 0.4.12 2021-10-18 [1] CRAN (R 4.1.2)
  rprojroot 2.0.2 2020-11-15 [1] CRAN (R 4.1.2)
  sessioninfo 1.2.2 2021-12-06 [1] CRAN (R 4.1.2)
  testthat 3.1.1 2021-12-03 [1] CRAN (R 4.1.2)
  usethis 2.1.5 2021-12-09 [1] CRAN (R 4.1.2)
  withr 2.4.3 2021-11-30 [1] CRAN (R 4.1.2)

[1] C:/Users/donne/Documents/R/win-library/4.1
[2] C:/Program Files/R/R-4.1.2/library

---

h2o.init()

H2O is not running yet, starting it now...

Note: In case of errors look at the following log files:
C:\Users\donne\AppData\Local\Temp\Rtmp29jwbb\file1b206222ba/h2o_donne_started_from_r.out
C:\Users\donne\AppData\Local\Temp\Rtmp29jwbb\file1b2055776ea0/h2o_donne_started_from_r.err

java version "11.0.10" 2021-01-19 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.10+8-LTS-162)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.10+8-LTS-162, mixed mode)

Starting H2O JVM and connecting: Connection successful!

R is connected to the H2O cluster:
H2O cluster uptime: 3 seconds 84 milliseconds
H2O cluster timezone: America/Chicago
H2O data parsing timezone: UTC
H2O cluster version: 3.36.0.1
H2O cluster version age: 9 days
H2O cluster name: H2O_started_from_R_donne_yuv566
H2O cluster total nodes: 1
H2O cluster total memory: 1.97 GB
H2O cluster total cores: 8
H2O cluster allowed cores: 8
H2O cluster healthy: TRUE
H2O Connection ip: localhost
H2O Connection port: 54321
H2O Connection proxy: NA
H2O Internal Security: FALSE
H2O API Extensions: Amazon S3, Algos, Infogram, AutoML, Core V3, TargetEncoder, Core V4
R Version: R version 4.1.2 (2021-11-01)

airlines_url <- "https://s3.amazonaws.com/h2o-airlines-unpacked/allyears2k.csv"
airlines <- h2o.importFile(path = airlines_url)
|=================================================================================================================================================================| 100%

NOTE that I took out the additional column subsetting which I believe to be unnecessary from the example in the docs

the results are valid but see it provides a confusing warning due to a bug

cols <- c("Dest", "IsArrDelayed", "IsDepDelayed")
h2o.group_by(data = airlines,

•          by = "Origin",
  

•          sum(cols),
  

•          gb.control = list(na.methods = "ignore", col.names = NULL))
  

  Origin sum_Dest sum_IsArrDelayed sum_IsDepDelayed
  1 ABE 5884 40 30
  2 ABQ 84505 545 370
  3 ACY 3131 9 7
  4 ALB 3646 49 50
  5 AMA 317 4 6
  6 ANC 100 0 1

[132 rows x 4 columns]
Warning message:
In if (is.na(col.idx)) stop("No column named ", col.name, " in ", :
the condition has length > 1 and only the first element will be used

add a column that doesn't exist to the vector

we get an error before that warning

cols <- c(cols, "fake")
h2o.group_by(data = airlines,

•          by = "Origin",
  

•          sum(cols),
  

•          gb.control = list(na.methods = "ignore", col.names = NULL))
  

Error in if (x == 0) stop("Cannot select row or column 0") else if (x > :
missing value where TRUE/FALSE needed
In addition: Warning message:
In if (is.na(col.idx)) stop("No column named ", col.name, " in ", :
the condition has length > 1 and only the first element will be used

moving this fake column to the front and now we get a different error (and still get the warning)

cols <- c("fake", "Dest")
h2o.group_by(data = airlines,

•          by = "Origin",
  

•          sum(cols),
  

•          gb.control = list(na.methods = "ignore", col.names = NULL))
  

Error in FUN(X[[i]], ...) : No column named fakeDest in data.
In addition: Warning message:
In if (is.na(col.idx)) stop("No column named ", col.name, " in ", :
the condition has length > 1 and only the first element will be used
{code}

[h2o-ops-ro]

JIRA Issue Details

Jira Issue: PUBDEV-8507
Assignee: Tomas Fryda
Reporter: N/A
State: Resolved
Fix Version: 3.36.0.2
Attachments: N/A
Development PRs: Available

[h2o-ops-ro]

Linked PRs from JIRA

#6004