# or with a vector of names: res = alter( for( ` name, value ` in mark(mtcars)) if(name %in% c( 'cyl', 'am')) as.character(value), data = mtcars ) str(res) #> 'ame': 32 obs. # 'data' argument example # specify which columns to map with a numeric vector of positions: res = alter( for( ` i, value ` in numerate(mtcars)) if(i %in% c( 1, 4, 5)) as.character(value), data = mtcars ) str(res) #> 'ame': 32 obs. # drop factors res = alter( for(i in iris) if( is.factor(i)) exclude()) str(res) #> 'ame': 150 obs. #> $ Species : chr 'setosa' 'setosa' 'setosa' 'setosa'. #> $ Sepal.Width : num 3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1. Fill in the blanks in the for loop to make the following true: price should hold that iterations price date should hold that iterations date This time, you want to know if apple goes above 116. The statements that follow the then statement can be any valid UNIX command, any executable user program, any executable shell script, or any shell statement with the exception of fi. of 5 variables: #> $ Sepal.Length: num 5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9. Here, The condition in the if statement often involves a numerical or string test comparison, but it can also be any command that returns a status of 0 when it succeeds and some nonzero status when it fails.

# convert factors to characters res = alter( for(i in iris) if( is.factor(i)) as.character(i)) str(res) #> 'ame': 150 obs. Data(iris) # scale numeric variables res = alter( for(i in iris) if( is.numeric(i)) scale(i)) str(res) #> 'ame': 150 obs. r setwd - set the working directory your scripts folder setwd( '/user/you/scriptrepo' ) pull all files and folders (including subfolders) into a character vector keep ONLY the files that END with '.R' or '.r' scriptlist <- list.files( pattern'.rR', recursive TRUE ) loop through and trigger scripts using source () for ( i in.

If loop in r