Square Roots by Newton's Method (SCIP example 1.1.7) in R code

Asked Jul 12 '19 at 01:57

Active Jul 12 '19 at 02:02

Viewed 108 times

I want to apply Newton's Method for square root through iterations in RStudio, but I keep getting error

"Error: C stack usage 7969204 is too close to the limit"

when I put a wrong sqrt in the 'g'. Instead, the code works fine when I write directly the right number (example: sqriter(2,4) --> 2)

Below is the code I wrote for it.

thank you for your help!

sqriter <- function(g,x){
  ifelse(goodguess(g,x), g, sqriter(improve(g,x), x))
}

goodguess <- function(g,x){
  abs(g*g-x)<0.001
}

average <- function(g,x){
  ((g+x)/2)
}

improve <- function(g,x){
  average(g, (g/x))
}

edited Jul 12 '19 at 02:02

shizhen

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asked Jul 12 '19 at 01:57

Nicolas Berho Montalvo

I solved it! I had a mistake in the "improve" function, The correct function is then: improve <- function(g,x){ average(g, (x/g)) – Nicolas Berho Montalvo Jul 12 '19 at 02:26
here's another way to write the function: sqriter2 <- function(g,x){ while(abs(g*g-x)>0.001){ print(g) g = improve(g,x) } } – Nicolas Berho Montalvo Jul 12 '19 at 02:27
3

You can write it as an answer (instead of comment) if you have solved it yourself. – Ronak Shah Jul 12 '19 at 02:42

Square Roots by Newton's Method (SCIP example 1.1.7) in R code

0 Answers0