CODEWITHSUNDEEP
rvectordimensions
user507
user507

Reputation: 233

How can I insert dimensions of a data matrix into a line of code?

I have a very simple line of code I would like to run. I am creating this vector:

 x1<- rep("T", 576)

However, I derived the number 576 from this line of code:

 dim(x)

(x is a dataframe which is 576 rows long)

I need to create vectors similar to x1 for many other other data frames which are all of varying dimensions. I do not want to have to manually type the dimension value into the rep formula every time. Is there a way to combine these two formulas into one?

Upvotes: 0

Views: 49

Answers (2)

watsonstevenc
watsonstevenc

Reputation: 1

Have you considered making a list of data frames and then writing a loop to calculate a new vector for each data frame? The below code creates two data frames of varying size, throws them in a list, and then uses a for loop to get the dimensions of each one and assigns that to a vector (obviously replace "z in 1:2" with however many data frames you have). Hope that helps.

x1<-data.frame(1:3,4:6)
x2<-data.frame(7:10,11:14)

x<-list(x1,x2)

z<-0

for (z in 1:2) {

t<-as.data.frame(lapply(x[z], dim))
t[1,1]

d<-rep("T",t[1,1])
assign(paste("vector",z,sep=""),d)
}

Upvotes: 0

toni057
toni057

Reputation: 604

Try dim(x)[1] or nrow(x) to extract the dimension and feed into your call:

x1 <- rep("T", nrow(x1))

Upvotes: 1

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