[R] grubbs test to detect all outliers

[Rui Barradas]

Às 14:09 de 28/04/2023, AbouEl-Makarim Aboueissa escreveu:
> *R: *Grubbs Test to detect all outliers Per group for all columns in a data
> frame
> 
> 
> 
> Dear All: good morning
> 
> I have a dataset (as an example) with two column factors (factor1 and
> factor2) and 5 numerical columns (X,Y,Z,U,V). The X and Y columns have same
> length as factor1; and Z, U, and V have same length as factor2. Please see
> dataset is copied below. Please note that all dataset columns have NAs
> values.
> 
> *Need help on this:*
> 
> 
> Can we use the grubbs.test() function to detect all outliers and replace it
> by NA in X and Y datasets per group in factor1; and in Z, U, and V datasets
> per group in factor2. Columns in the dataframe have different lengths, but
> when I read the .csv file, R added NA values for the shorter columns.
> 
> If you need the .csv data file, please let me know.
> 
> 
> Thank you very much for your help in advance.
> 
> 
> 
> 
> install.packages("outliers")
> library(outliers)
> 
> datafortest<-read.csv("G:/data_for_test.csv", header=TRUE)
> datafortest
> 
> datafortest<-data.frame(datafortest)
> 
> datafortest$factor1<-as.factor(datafortest$factor1)
> datafortest$factor2<-as.factor(datafortest$factor2)
> 
> str(datafortest)
> 
> ##### tried to use grubbs.test() on a single column of the dataframe, but
> still not working
> tests.for.outliers.X<- grubbs.test(datafortest$X, na.rm = TRUE, type=11)
> 
> 
> ####################################
> 
> *grubbs.test() on a single dataset: but this can only detect if the min and
> the max are outliers.*
> 
> 
> xx999<-c(0.088,1,2,3,4,5,6,7,8,9,88,98,99)
> grubbs.test(xx999, type=11)
> 
> 
> 
> 
> With many thanks
> 
> Abou
> 
> 
> 
> factor1      X            Y         factor2          Z           U
>    V
> 1     4455.077 888 1 999           NA 999
> 1     4348.031 333 1 475            NA 240
> 1    9999.789 618 1 507 252 394
> 1    3813.139 417 1 603 332 265
> 1  7512.65 344 1 442 216           NA
> 1     5642.667            NA 1 486 217 275
> 1     6684.386 341 1 927 698 479
> 2     5165.731 999 1 971 311 562
> 2 NA 265 1 388 999 512
> 2     3259.241 557 2 888 444 777
> 2     3288.383 234 2 514            NA 322
> 2      1997.878 383 2 409 311           NA
> 2       99990.61           NA 2 546 327 728
> 2       2655.977          NA 2 523 228 653
> 3      3189.49 7777 2 313 456 450
> 3      1826.851 287 2 296 412 576
> 3      4386.002 352 2 320 251         NA
> 3      3295.091 308 2 388 888 396.5
> 3      2120.902 526 3 9999 398 888
> 3 NA 489 3 677 438 307
> 3      2056.123 291 3 555 428 219
> 3      1995.088 444 3              NA 319           NA
> 3 NA 349 3 479           NA 321
> 3      2539.873 333 3 257 406 417
>        3 313 334 409
>        3 296 465 546
>        3 320 180 523
>        3 388 999 313
> 
> 
> 
> ______________________
> 
> 
> *AbouEl-Makarim Aboueissa, PhD*
> 
> *Professor, Mathematics and Statistics*
> *Graduate Coordinator*
> 
> *Department of Mathematics and Statistics*
> *University of Southern Maine*
> 
> 	[[alternative HTML version deleted]]
> 
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Hello,

Please post the output of

dput(datafortest)

your data is difficult to read into a R session.


Hope this helps,

Rui Barradas