CODEWITHSUNDEEP
r
user6789
user6789

Reputation: 1

How do you write a sequence as a vector?

I have a vector "I" which we can take for example to be (0,1,2,3.....) till an unknown length. I want to create a vector such that x^(I-1) so it will be a vector that looks like (0,x,x^2...). However I do not know how to write this code and I tried (x^I-1) alone doesn't work.

Upvotes: 0

Views: 413

Answers (3)

TTS
TTS

Reputation: 1928

EDIT*** Read r2evan's comments to understand why this is not a recommended solution.

This will take vector z and feed it it into the function to create the resulting vector. Simply adjust your x value (in this case, the 2)

z <- c(1:5)

new_vector <- sapply(z, function(y) 2 ^ y)

The output values in the new vector then would be x^0, x^1, x^2, x^3... etc.

Upvotes: 0

ThomasIsCoding
ThomasIsCoding

Reputation: 101099

You can use seq(l) to construct a l-length vector from 1 to l as powers. Since you are pursuing a start from 0, so you can use seq(l)-1.

Then, you choose a value of x, and generate the desired vector via

x**(seq(l)-1)

If you have x and l as variables, you can define your custom sequence generator like below

vgen <- function(x,l)  x**(seq(l)-1)

and use it like

> vgen(3,7)
[1]   1   3   9  27  81 243 729

Upvotes: 0

Rich Pauloo
Rich Pauloo

Reputation: 8392

As commented on your question, R is vectorized. This means that you can specify a vector y of integers, a variable x of length 1, and then take x to the power of y via x^y:

y <- 0:10
x <- 2
x^y

which returns:

[1]    1    2    4    8   16   32   64  128  256  512 1024

Upvotes: 1

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