I want to be able to see summary output for few columns of iris (inbuilt dataset) inside loop using below construct, I saw here , mget might be a solution but guess its not. Can someone help here with the latest & effective way to run it
l <- c("Sepal.Length","Sepal.Width")
for(i in l){
print(summary( mget(paste0("iris$",l))))
}
I get an error on running above
Error: value for ‘iris$Sepal.Length’ not found
Q2 How would this work for different dataframe
l <- c("iris","mtcars")
for(i in l){
print(summary( mget(l)))
}
Since you are having column names in a vector, you don't need to get them. Just use it directly as index [[ to extract the column.
Base R:
sapply(l, function(x) summary(iris[[x]]))
Sepal.Length Sepal.Width
Min. 4.300000 2.000000
1st Qu. 5.100000 2.800000
Median 5.800000 3.000000
Mean 5.843333 3.057333
3rd Qu. 6.400000 3.300000
Max. 7.900000 4.400000
Q2:
In this case because you need to get the value of an object, you literally need the get() function.
sapply(c("iris","mtcars"), function(x) summary(get(x)))
$iris
Sepal.Length Sepal.Width Petal.Length Petal.Width
Min. :4.300 Min. :2.000 Min. :1.000 Min. :0.100
1st Qu.:5.100 1st Qu.:2.800 1st Qu.:1.600 1st Qu.:0.300
Median :5.800 Median :3.000 Median :4.350 Median :1.300
Mean :5.843 Mean :3.057 Mean :3.758 Mean :1.199
3rd Qu.:6.400 3rd Qu.:3.300 3rd Qu.:5.100 3rd Qu.:1.800
Max. :7.900 Max. :4.400 Max. :6.900 Max. :2.500
Species
setosa :50
versicolor:50
virginica :50
$mtcars
mpg cyl disp hp
Min. :10.40 Min. :4.000 Min. : 71.1 Min. : 52.0
1st Qu.:15.43 1st Qu.:4.000 1st Qu.:120.8 1st Qu.: 96.5
Median :19.20 Median :6.000 Median :196.3 Median :123.0
Mean :20.09 Mean :6.188 Mean :230.7 Mean :146.7
3rd Qu.:22.80 3rd Qu.:8.000 3rd Qu.:326.0 3rd Qu.:180.0
Max. :33.90 Max. :8.000 Max. :472.0 Max. :335.0
drat wt qsec vs
Min. :2.760 Min. :1.513 Min. :14.50 Min. :0.0000
1st Qu.:3.080 1st Qu.:2.581 1st Qu.:16.89 1st Qu.:0.0000
Median :3.695 Median :3.325 Median :17.71 Median :0.0000
Mean :3.597 Mean :3.217 Mean :17.85 Mean :0.4375
3rd Qu.:3.920 3rd Qu.:3.610 3rd Qu.:18.90 3rd Qu.:1.0000
Max. :4.930 Max. :5.424 Max. :22.90 Max. :1.0000
am gear carb
Min. :0.0000 Min. :3.000 Min. :1.000
1st Qu.:0.0000 1st Qu.:3.000 1st Qu.:2.000
Median :0.0000 Median :4.000 Median :2.000
Mean :0.4062 Mean :3.688 Mean :2.812
3rd Qu.:1.0000 3rd Qu.:4.000 3rd Qu.:4.000
Max. :1.0000 Max. :5.000 Max. :8.000