Text Formatting ⇒ Incorrect spacing between function name and following "("

[zaradek]

Why are there different horizontal spaces after the two log functions in the result of the following code?

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$\log\left(3\right)+\log(3)$

See attached the produced pdf.

Thanks,
Máté

[emime]

The right use of a math function is by enclosing the arguments within {}. The following two log functions are equally spaced.

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$\log{\left(3\right)}+\log{(3)}$

By writing this

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$\log(3)$

you are not feeding the function with its argument...
Perhaps the following shows the difference between using \left( or (

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$a\left(3\right)\,a(3)$

\left(\right) has a different behavior than (). Normally, you need to use \left(\right) to adapt the parenthesis when using \frac or array and improve spacing.

[localghost]

The right use of a math function is by enclosing the arguments within {}. [...]

These commands have no arguments. Their only purpose is to typeset the according math function name in upright shape inside math environments.

Why are there different horizontal spaces after the two log functions in the result of the following code? [...]

At the moment I can't comprehend the problem. Perhaps the "Math mode" document gives some useful hints.


Best regards
Thorsten

[zaradek]

Thanks for your answers. I believed the same, namely \log is just standing instead e.g. \mathrm{log}.

But I still don't know, how to avoid the huge space between \log and \left(.

See another example attached. The spacings are too big in the first line but they are correct in the second line. Do you know how to fix the first line?

Máté

[localghost]

[...] Do you know how to fix the first line? [...]

I'd say you've given the answer with the second line by adjusting the parenthesis manually. Despite the wrong explanation the method of emime could be a solution. A good example for eliminating horizontal space is the following code.

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$E=mc^2$

$E{=}mc^2$

[zaradek]

So, can we consider this issue as a bug in the latex?

On the other hand, what works in your example doesn't work in this case:

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$\log{\left(3\right)}$

It has the same huge space after the log.

Máté

[localghost]

So, can we consider this issue as a bug in the latex? [...]

I don't think so. I consider the bigger space as the better one. But perhaps the document I mentioned earlier can give a hint. Search it for "delimiter spaces".

[emime]

Sorry for the wrong explanation. I meant that generally is safer to use {} (typical case is ^ or \sqrt).

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\[a^23\neq a^{23}\]

I consider the extraspace the better one too, that's why I suppose {} gets the right behavior, even in common math functions.
Anyway, if you don't like extraspace use a negative hspace.

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\[\log\hspace{-3pt}{\left(k\right)\cdot x}\]

[zaradek]

I see your opinion, but I'm on the contrary. :)
According to my experience in math typesetting from books and publications, there is never space between the function symbol/name and the opening bracket following that. But then it may not be so obvious as I believe...

By the way, simply the \! seems to produce the same space as in the case of using manual parenthesis.

Máté