Question

In R dataframes How to select :1/

a/--all columns for 6 cylinder cars with horsepower >=to 100

b/-only columns mpg,cyl,disp and hp for cars with weight >=3000lbs

Answer 1

Install dplyr package and then use filter function to give condition.

Select function to extract the required columns

There is an inbuilt data frame in R mtcars.,executed the same on mtcars dataframe

Rcode for stepA:

step1 <- filter(dataframe, (cylinder ==8 & horsepower >= 100))

b/-only columns mpg,cyl,disp and hp for cars with weight >=3000lbs

Rcode for stepb:

step2 <- filter(dataframe, (weight>=3000))
Requrdcol <- step2 %>% select(mpg,cyl,disp,hp,wt)

Rscreenshot:

for stepA:

For stepb: