log2
Dec 16, 2009 at 7:26pm
log2Hi, Thanks for your help! NP 

Dec 16, 2009 at 9:11pm
expr log($f1,2) you give the base as second value, the values are separated by a 

Dec 16, 2009 at 10:11pm
In the [expr] object it seems that log() and ln() bother calculate the natural logarithm. When I try putting two arguments into log() I get an error saying it only understands one argument. What you want to do is use the base changing rule of logarithms which states loga(x) = (logb(x)/logb(a)) where the emphasised letters represent the base of the logarithm. So if you want to be in base two use something like: [expr log10($f1)/log10(2)] lh 

Dec 16, 2009 at 10:13pm
Hey, in my version of expr that doesn’t work. That’s why I always do it like this: expr log10($f1)/log10(2). 

Dec 17, 2009 at 12:17am
let see first if my version of expr really can do what i suggested. :P 

Dec 17, 2009 at 5:21pm
expr log($f1)/log(2) or expr log10($f1)/log10(2) or expr ln($f1)/ln(2) 

Dec 18, 2009 at 3:51am
Thank you for that precious help! loga(x) = logb(x)/logb(a) This is fascinating… NP 

Sep 4, 2012 at 3:01pm
thx to luke hall also from me. 

Jul 3, 2013 at 7:28pm
Is it ever too late for thank you? I think not. Thanks for the math lesson Luke. 
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