Task

Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.

The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.

For example, considering:

   x = {1, 2, 3, 1e11};
   y = {1, 1.4142135623730951, 1.7320508075688772, 316227.76601683791}; 
                                                          /* sqrt(x) */
   xprecision = 3;
   yprecision = 5;

The file should look like:

   1    1
   2    1.4142
   3    1.7321
   1e+011   3.1623e+005

This task is intended as a subtask for Measure relative performance of sorting algorithms implementations.




writexy <- function(file, x, y, xprecision=3, yprecision=3) {
  fx <- formatC(x, digits=xprecision, format="g", flag="-")
  fy <- formatC(y, digits=yprecision, format="g", flag="-")
  dfr <- data.frame(fx, fy)
  write.table(dfr, file=file, sep="\t", row.names=F, col.names=F, quote=F)
}
 
x <- c(1, 2, 3, 1e11)
y <- sqrt(x)
writexy("test.txt", x, y, yp=5)