FW: [Maxima] bug report, or am I doing something wrong?

Luke Sharkey 99LSharkey at ormskirk.lancs.sch.uk
Fri Feb 10 04:55:26 CST 2006

```So does nobody have any feedback for me on the log question, etc.?

-----Original Message-----
From: Luke Sharkey
Sent: 06 February 2006 11:01
To: 'maxima-admin at math.utexas.edu'
Subject: RE: [Maxima] bug report, or am I doing something wrong?

"Maxima's choice of branches for multi-valued functions."
So what can be done about it:  when can we know whether the calculated
integral / differential is more likely to be corrector not?  Am I just
going to have to plot it each time?

Also:  (this caused me a *lot* of headache before I realised what was
going on).
Its about the log() function.  I checked the documentation, and finally
realised that log() actually means the *natural logarithm*.

Firstly, how does one do log to the base 10 with maxima?

Secondly, on every calculator, maths program (Microsoft Excel, etc) and
textbook I have ever used, "log" has ALWAYS meant "log to the base 10",
and "ln()" log to the base e", unless it is specified in some way, e.g.
log2() meaning log to the base 2.  I propose that the "log" function
should be changed in meaning from natural log to log to the base 10.  I
personally think a new function should be created as ln() for natural
logarithms.

At the very least, every time the log function is used, some text should
appear below indicating that the such and such a calculation involving a
log has been "calculated with log to the base xyz" underneath the
output, so people like me don't use it assuming that "log" means "log to
the base 10".

Thirdly, programs like Excel use "LOG" in uppercase.  Maxima should be
able to recognise when "LOG" is typed, or copied and pasted in from
Excel, that it should be recognised as "log": this should be automatic.

Thanks.
L Sharkey
________________________________________
From: maxima-admin at math.utexas.edu [mailto:maxima-admin at math.utexas.edu]
On Behalf Of Robert Dodier
Sent: 31 January 2006 15:45
To: Maxima List
Cc: Luke Sharkey
Subject: [Maxima] Fwd: bug report, or am I doing something wrong?

A quick look suggests the results below stem from Maxima's
choice of branches for multi-valued functions.

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