Math & Science ⇒ It is possible to make this command?

[Yue]

I am writing a paper and I have defined these commands:

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\newcommand{\creau}[1]{u_{#1}^*}
\newcommand{\anniu}[1]{u_{#1}^{\vphantom{*}}}

The

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\vphantom

is there to e.g make the k's in

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\creau{k}\anniu{k}

be at the same height.

So now, when I write

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{\anniu{k}}^2

, it looks so ugly because of the $\phantom$ command.

Is there a way to define

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\anniu{}

so that when I write

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{\anniu{k}}^2

, I get the normal

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u_k^2

?

I could of course change it all manually, but as I have used the

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\anniu{}

100 times, It will be very hard...

[meho_r]

Even without \vphantom, you're in trouble here because you haven't used custom made commands correctly. What I mean is that {\anniu{k}}^2 is just wrong for the purpose because it is not the same as u_k^2 but actually {u_k}^2.

So, when you're using custom made commands which may have a second argument too, you may define them with two arguments and a default value for times when only one argument is specified (but which is ignored when you actually do specify both arguments), something like this:

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\documentclass{book}

\newcommand{\creau}[1]{u_{#1}^*}
\newcommand{\anniu}[2][\vphantom{*}]{u_{#2}^{#1}}% Inside the second square brackets set comes a default value

\begin{document}

$\creau{k}-u_k^2-{u_k}^2-\anniu{k}-\anniu[2]{k}$

\end{document}

So, in the example, \anniu{k} will result in u_k^{\vphantom{*}} (since only one argument is specified so the default value is in effect), while \anniu[2]{k} will give u_k^2, ignoring \vphantom{*} completely because both arguments are explicitly given.

[Yue]

Thx this was helpful