Grapher: base of logarithms

Question

Grapher: base of logarithms

I can't find anywhere how to set a logarithm's base (different from 10 or e), i've tried to use the lower index (pressing underscore) mut it does not work.
This app has really poor documentation (at least in the italian localization of tiger)

Any suggestions? Thanks everybody for your time.

Posted on Aug 25, 2005 4:14 AM

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Answer 1

Stutz Jr

Level 1

25 points

Aug 25, 2005 8:07 AM in response to Leandro Pedroni

I guess they figured with such a stright forward conversion available, they didn't think it was necessary to include the extra facility (that would likely have involved more complex code or otherwise have used the above conversion anyway :P) for the limited number of times most people would need the other bases?

I haven't really used the grapher that much, is it possible to just label the plots perhaps?

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Answer 2

Aug 25, 2005 11:31 AM in response to Stutz Jr

At the end I defined a function called lo_n(x) as log(n)/log(x).

(underscore stands for lower index)

perhaps you're right about avoiding to code this function, but i still think it's a bit strange...

Thanks anyway.
Leandro

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Answer 3

Sep 14, 2005 8:55 AM in response to Leandro Pedroni

Most advanced graphers leave out a different base log function, e.g. the TI-89. I believe it is assumed that if you are working with logarithms you are working with standard base. And, as was mentioned, if you want a different base the conversion is trivial and not worth the extra code. You will mostly find alternate base functions on algebra and trig calculators like the TI-86.

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Answer 4

Stutz Jr

Level 1

25 points

Aug 25, 2005 5:24 AM in response to Leandro Pedroni

I'm pretty sure the conversion you are after is:

log(x)N = Log N / Log x

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Answer 5

Aug 25, 2005 5:56 AM in response to Stutz Jr

right, but ain't there a way to insert directly a different base, just to read it more practically

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