CODEWITHSUNDEEP
rfunctionmin
unknown
unknown

Reputation: 47

Using Min and max function inside a function

I have created a function which uses 2 variables to do grouping and uses third variable to create min and max for each groups. But the min and max function gives wrong output. It gives the minimum and maximum for entire dataset and not for each group.

myfunction= function(x,a,b,column) {
  temp=group_by(x,x[[a]],x[[b]])
   Score=summarise(temp,Totals=n(),Mnscore=min(x[[c]]),Mxscore=max(x[[c]]))
 return(Score)
}

myfunction(dataset,"a","b","c")


Actual Results:
a b Totals  Min Max
1 1  10     15  50
1 2  20     15  50
1 3  30     15  50

Expected results:
a b Totals  Min Max
1 1  10     20  48
1 2  20     21  49
1 3  30     15  50

Upvotes: 0

Views: 242

Answers (3)

Onyambu
Onyambu

Reputation: 79238

to write a function, you could do the following:

library(tidyverse)
myfunction= function(x,a,b,column) 
  {
  column <- enquo(column)
  vars <- enquos(a,b)
  x %>% 
    group_by(!!!vars) %>% 
    summarise(Totals=n(),Mnscore=min(!!c),Mxscore=max(!!column))
}

then call this inputing a,b,c as symbols and not characters

myfunction(dataset,a,b,column)

Upvotes: 1

J.P. Le Cavalier
J.P. Le Cavalier

Reputation: 1345

You can use the data.table package if you want a very effective way to solve your problem. Try the following minimal reproducible example.

library(data.table)
set.seed(20191011L)

data <- data.table(
  V1 = letters[sample(3, 20, TRUE)],
  V2 = letters[sample(3, 20, TRUE)],
  V3 = runif(20)
)

fun <- function(data, groups, target){

  data[, .(min=min(get(target)), max=max(get(target))), mget(groups)]

}

fun(data, c("V1", "V2"), "V3")

##     V1 V2        min       max
##  1:  b  c 0.20653948 0.4618063
##  2:  a  a 0.09560888 0.3347064
##  3:  b  b 0.75071480 0.7507148
##  4:  c  a 0.66410519 0.8258410
##  5:  c  c 0.01303751 0.7635212
##  6:  a  b 0.04770186 0.6332439
##  7:  b  a 0.25069813 0.9008885

Upvotes: 1

makeshift-programmer
makeshift-programmer

Reputation: 499

Try this:

require(dplyr)

result = dataset %>% 
  dplyr::group_by(a,b) %>% 
  dplyr::summarise(Totals = n(),
                   Mnscore = min(c),
                   Mxscore = max(c))

Let me know if it works.

Upvotes: 0

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