# [tex4ht] Black stripe on formula rendering

Thompson,Paul Paul.Thompson at SanfordHealth.org
Tue Feb 10 18:38:17 CET 2015

I sent this note to Giuseppe, and it apparently worked correctly.

One thing I do is ensure that no hidden characters or spaces are affecting results:

\documentclass{article}
\begin{document}%
$% k_v=\min\begin{cases}% 1 \\% \frac{k_{n}(1+\frac{1,1i^{1,5}}% {\sqrt{h}})}{\sqrt{h}(\sqrt{\alpha(1-\alpha)}+% 0,8\frac{x}{h}\sqrt{\frac{1}{\alpha}-\alpha^{2}})}% \\% \end{cases}%$%
\end{document}

This is generally good advice with LaTeX and friends - ensure that your results are not being affected by what you don't see.

-----Original Message-----
From: tex4ht [mailto:tex4ht-bounces at tug.org] On Behalf Of Giuseppe Pica
Sent: Tuesday, February 10, 2015 10:36 AM
To: Michal Hoftich
Cc: tex4ht at tug.org
Subject: Re: [tex4ht] Black stripe on formula rendering

Hi Michal,
My project is very huge, because I'm using the same latex source for dynamic help (tex4ht) and printing (pdflatex).
My latex preamble loads many many packages, but I have no problems except that in some formulas. It seems to happen in the formulas that make use of the cases environment.
I also tried to use:      \left{   \begin{array} ... \end{array} \right.
but the problem is the same.
However, there are cases where the "cases" environment does not give me problems.
Regards.
-j

Il 10/02/2015 16:21, Michal Hoftich ha scritto:
> Hi Giuseppe,
>
> could you please post minimal working example which produces the
> error? When I tried
>
> -----
> \documentclass{article}
> \begin{document}
> $> k_v=\min\begin{cases} > 1 \\ > \frac{k_{n}(1+\frac{1,1i^{1,5}}{\sqrt{h}})}{\sqrt{h}(\sqrt{\alpha(1-\a > lpha)}+0,8\frac{x}{h}\sqrt{\frac{1}{\alpha}-\alpha^{2}})} > \\ > \end{cases} >$
> \end{document}
>
> the output was correct. So maybe the problem is with some package you use.
>
> Regards,
> Michal
>
> 2015-02-10 12:39 GMT+01:00 Giuseppe Pica <jospic at gmail.com>:
>> Hi,
>> the following latex code produces a black stripe as shown in figure.
>>
>> $>> k_v=\min\begin{cases} >> 1 \\ >> \frac{k_{n}(1+\frac{1,1i^{1,5}}{\sqrt{h}})}{\sqrt{h}(\sqrt{\alpha(1-\ >> alpha)}+0,8\frac{x}{h}\sqrt{\frac{1}{\alpha}-\alpha^{2}})} >> \\ >> \end{cases} >>$
>>
>> http://www.iperspace.it/main121x.png
>>
>> How can I fix this?
>> Regards
>> -j

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