Oops, yes, sorry, careless of me. Thanks,
-- Raul On Mon, Jan 29, 2018 at 4:12 AM, Rob Hodgkinson <[email protected]> wrote: > Minor correction Raul (- instead of +) ? > ... use (8: + (2&^) - (2&^)@(2&*)) > > So Skip, just to clarify to see this solution put through Newton-Raphson; > > 1) Create the Newton-Raphson adverb as you stated earlier; > N=: 1 : '- u % u d. 1’ > > 2) Apply for a number of iterations using ^: and give it an initial value of > 1 … fn N (^:iterations) start-value > (8: + (2&^) - (2&^)@(2&*))N (^:20) 1 > 1.75372 > > 9!:11]14 NB. or increase print precision > (8: + (2&^) - (2&^)@(2&*))N (^:20) 1 > 1.7537248941553 > > Hope that clarifies things, as without the function appropriately defined as > Raul described, N returns a Domain Error if it can’t work with the function. > > Rob > >> On 29 Jan 2018, at 7:57 pm, Raul Miller <[email protected]> wrote: >> >> d. 1 wants to be able to use the chain rule for 2^2*x, and it seems >> like the implementation was from an early version of J, and has not >> kept up with all the more recent changes. So, you should put that >> changed term into an f@g form. >> >> In other words, use (8: + (2&^) + (2&^)@(2&*)) >> >> Thanks, >> >> -- >> Raul >> >> >> On Mon, Jan 29, 2018 at 1:46 AM, Skip Cave <[email protected]> wrote: >>> I see what I did wrong. >>> >>> The equation is: 8 + (2^x) - 2^2*x = 0 >>> >>> The third term is (2^2*x) not (2^2^x) >>> >>> That should get close to the answer x=1.75372 >>> >>> I'm mostly interested in how to formulate the code to implement the Newton >>> Raphson solution >>> using >>> >>> N=: 1 : '- u % u d. 1' >>> >>> In the NR code, where does the equation verb go? >>> How does it need to be structured? Where does the iteration count limit go? >>> >>> Skip >>> >>> >>> >>> >>> Skip Cave >>> Cave Consulting LLC > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
