# How to print negative value with currency

At the moment my report print currency values with siunitx with \$\numprint{12} But negative values displayed as$-12.00

I would like to display it as:

-$12.00 Or you think$-12.00 is ok too for US ?

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Welcome to TeX.SE! How is the macro \numprint defined? (It doesn't seem to be a macro that's set up by the siunitx package.) On the ways of displaying negative amounts of money: There are a quite a few conventions out there, and they depend in part on the currency ($, £, or some other currency unit) in use. The $-12.00 look is reminiscent of how some spreadsheets are set up for calculations with currencies. However, I do not think it's a common way of displaying negative amounts of dollars in running text. I honestly don't know if it's a common display form for other currency units. –  Mico Apr 21 '14 at 4:59

If you're going to use a negative sign with dollars, I would definitely put the negative sign before the dollar sign.

Here's a MWE which takes advantage of the fact that siunitx uses expl3 syntax:

\documentclass{article}
\usepackage{siunitx}

\ExplSyntaxOn
\def\aecompareTF#1#2#3{\fp_compare:nTF{#1}{#2}{#3}}
\def\aeabs#1{\fp_abs:n{#1}}
\ExplSyntaxOff

\sisetup{%%
group-separator={,},
round-precision=2,
round-mode=places,
round-integer-to-decimal}

\def\mydollars#1{%%
\aecompareTF{#1<0}
{\SI{\aeabs{#1}}[-\$]{}} {\SI{#1}[\$]{}}}

\pagestyle{empty}
\begin{document}

\mydollars{12350.30}

\mydollars{-12350.30}

The effect of \verbround-integer-to-decimal:

\mydollars{3}

\end{document}


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Dear Mr. Ellett, Thank you very much for your fast reply. I'm using latex to generate PDF and it reports an error: ( FP-ROUND ) ( FP-MUL ) ( FP-ROUND ) ( FP-DIV ) ! Argument of \fp_compare_aux_v:w has an extra }. Is it possible to make changes for latex ? I tried to search myself, but there is very few information about fp_compare. –  Sergio Apr 22 '14 at 8:40
@Sergio My first thought is that perhaps you need to update to the most current version of LaTeX. If the problem persists after updating, you might want to post a new question. –  A.Ellett Apr 22 '14 at 12:26
@sergio You can find information about the expl3 code I've used by running texdoc interface3. –  A.Ellett Apr 22 '14 at 12:27