L ljcox Well-Known Member Sep 1, 2007 #21 Bill, I don't understand why you have exp(1)* rather than ln And it is RC ln{1/(1 - Vc/V)} Last edited: Sep 1, 2007
blueroomelectronics Well-Known Member Sep 1, 2007 #22 The "Just BASIC" compiler does not have an ln() statement. exp(1) [2.71828183] seems to work fine, I'll remove the brackets.
The "Just BASIC" compiler does not have an ln() statement. exp(1) [2.71828183] seems to work fine, I'll remove the brackets.
ericgibbs Well-Known Member Most Helpful Member Sep 2, 2007 #23 blueroomelectronics said: The "Just BASIC" compiler does not have an ln() statement. exp(1) [2.71828183] seems to work fine, I'll remove the brackets. Click to expand... Bill, Some Basics consider the 'log' statement as meaning natural logs to base 'e' Try 'print log(2.71828183)' you most likely get '1', this will confirm that your Basic considers 'log' as a natural log reference.== 'ln' Last edited: Sep 2, 2007
blueroomelectronics said: The "Just BASIC" compiler does not have an ln() statement. exp(1) [2.71828183] seems to work fine, I'll remove the brackets. Click to expand... Bill, Some Basics consider the 'log' statement as meaning natural logs to base 'e' Try 'print log(2.71828183)' you most likely get '1', this will confirm that your Basic considers 'log' as a natural log reference.== 'ln'
E eng1 New Member Sep 2, 2007 #24 ericgibbs said: Bill, Some Basics consider the 'log' statement as meaning natural logs to base 'e' Click to expand... Eric, you're right. The manual of that compiler says: LOG(n) Description: This function returns the natural logarithm of n. Usage: print log( 7 ) produces: 1.9459101 Click to expand... BTW, it would be easy to get natural logarithm of x if you could use only base-10 logarithms: ln (x) = 2.302585 * log10 (x)
ericgibbs said: Bill, Some Basics consider the 'log' statement as meaning natural logs to base 'e' Click to expand... Eric, you're right. The manual of that compiler says: LOG(n) Description: This function returns the natural logarithm of n. Usage: print log( 7 ) produces: 1.9459101 Click to expand... BTW, it would be easy to get natural logarithm of x if you could use only base-10 logarithms: ln (x) = 2.302585 * log10 (x)
Hero999 Banned Sep 2, 2007 #25 I never saw the point of the exp function, surly it's easier to do 2.71828183^x.
tkbits Member Sep 2, 2007 #26 Not really. x ^ y where y is non-integer is calculated as base ^ (y * log-base x). If base is 10, then x ^ y is 10 ^ (y log10 x). We used to do this with paper, pencil, and a table of logarithms. If base is e, then x ^ y is e ^ (y log-e x), or exp(y * ln(x)). There are approximating polynomials for doing this on a computer.
Not really. x ^ y where y is non-integer is calculated as base ^ (y * log-base x). If base is 10, then x ^ y is 10 ^ (y log10 x). We used to do this with paper, pencil, and a table of logarithms. If base is e, then x ^ y is e ^ (y log-e x), or exp(y * ln(x)). There are approximating polynomials for doing this on a computer.
Papabravo Well-Known Member Sep 6, 2007 #27 The "ln" is an abreviation for "natural" or "Naperian" logarithms. Named after the Scottish mathemetician John Napier. https://en.wikipedia.org/wiki/John_Napier
The "ln" is an abreviation for "natural" or "Naperian" logarithms. Named after the Scottish mathemetician John Napier. https://en.wikipedia.org/wiki/John_Napier