To create a data frame, R function data.frame() can be used. For column values, you can create vectors of the same size. The name of the column can be declared in the function itself.
Here is an example:
> xvals = c(10,20,30,40,50)
> yvals = c(100,200,300,400,500)
> df <- data.frame(x=xvals, y=yvals)
> df
x y
1 10 100
2 20 200
3 30 300
4 40 400
5 50 500