R: R: LOG(x) BASIC function
Right, good observation ;-) Thanks, Stefano -Messaggio originale- Da: shevek <[EMAIL PROTECTED]> A: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Data: lunedì 22 marzo 1999 14.32 Oggetto: Re: R: LOG(x) BASIC function >On Fri, 19 Mar 1999, Stefano Fronteddu wrote: > >> Taylors rule says that >> >> log (1+x) = x - x^2/2 + x^3/3 + + (x^(2n+1)) / (2n+1)! >> >> so >> >> log x = (x-1) - (x-1)^2/2 + ... +(-1)^n-1 * ((x-1)^n) / n > >This is correct, but remember that this is an approximation near x=0 (in >the original form), so if you want to know log(100), it will have a large >error. For more correct values over the whole interval (you need to >specify one, preferribly not being infinitely long), there are other ways >that take longer for each step, but come much closer to the desired >function if x is large. > >Bye, >shevek > > > >MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put >in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the >quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/) > MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: R: LOG(x) BASIC function
On Fri, 19 Mar 1999, Stefano Fronteddu wrote: > Taylors rule says that > > log (1+x) = x - x^2/2 + x^3/3 + + (x^(2n+1)) / (2n+1)! > > so > > log x = (x-1) - (x-1)^2/2 + ... +(-1)^n-1 * ((x-1)^n) / n This is correct, but remember that this is an approximation near x=0 (in the original form), so if you want to know log(100), it will have a large error. For more correct values over the whole interval (you need to specify one, preferribly not being infinitely long), there are other ways that take longer for each step, but come much closer to the desired function if x is large. Bye, shevek MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
R: LOG(x) BASIC function
>very much like a log. You could use the taylor-series, which can be >calculated quite quick, but is not a very good approximation. I don't know >the taylor-series by heart, but I could look it up. In case you want to >start programming, it will be of the form: >y=a+bx+cx^2+dx^3+ Taylors rule says that log (1+x) = x - x^2/2 + x^3/3 + + (x^(2n+1)) / (2n+1)! so log x = (x-1) - (x-1)^2/2 + ... +(-1)^n-1 * ((x-1)^n) / n I hope to be helpful to you, bye Stefano --- Fronteddu Stefano Student in Software Engineering [EMAIL PROTECTED] [EMAIL PROTECTED] http://members.xoom.it/dudduMSX, Sardinia, Robotics, Friends http://computer.digiland.it/1461 MSX Soft Tips Page Member of Miri Software - Italy http://Frengo.dragonfire.net/MSX.HTM ICQ: 21401454 0338/3645458 MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
