[l2h] Black bars under integral signs when the limitsof integration are -\infty and +\infty or an algebraicfraction for each of the upper and lower limits

Pat Somerville l_pat_s at hotmail.com
Wed Apr 13 06:08:49 CEST 2011

Here is more information on this issue of unwanted black line segments under 
especially the .html equivalent of a portion of the LaTeX command \in\limits 
_{-\infty}^{+\infty}.  For LaTeX and LaTeX2HTML use currently I am using an 
OpenSUSE-11.3 Linux operating system; LaTeX2e of September 24, 2009; 
LaTeX2HTML Version 2008 (1.71); Netpbm 10.35.74-2.21.i586 (Netpbm 10.35.74 
compiled on July 5, 2010); and, according to the LaTeX2HTML output, dvips(k) 
5.98 of the year 2009.

1) My test LaTeX file Throwaway7.tex contained a portion of a LaTeX command 
that was close to \int\limits _{-\infty}^{+\infty}.  The command "latex 
Throwaway7.tex" produced the file Throwaway7.dvi.  After opening that .dvi 
file with the program Okular there was no black line segment underlining the 
integral sign and its limits.  So this prompts a conceivable workaround 
solution that ought to work to produce the integral sign and its limits 
without the undesirable black line segment in a .html file using LaTeX2HTML:

Conceivable workaround solution A

a) Print onto paper the page of the .dvi file containing the desired 
mathematical expression without an unwanted black line segment underlining 

b) Scan that piece of paper with a scanner.  For the scanner program used 
with my scanner unfortunately .png (Portable Network Graphics) is not among 
the available choices of formats for scanned files; however, even if I could 
produce a .png document with my scanning program, I would not know how to 
make LaTeX2HTML use it as a portion of an equation.  So instead I could 
choose the Mult-Tagged Image File Format, .tif file for the scanned file and 
in the next step work with it.

c) With the Gnu Not Unix (GNU) Image Manipulation Program (GIMP) 2.6.8 I 
could conceivably convert the .tif file to an Encapsulated PostScript (.eps) 
file suitable for use as a figure in a .tex, LaTeX document.

d) Run latex and latex2html.... commands on the resulting .tex file to 
produce mathematical expressions without the undesired black line segments 
under some of them.

Conceivable workaround solution B

In the .tex file define $a=-\infty$ and $b=+\infty$.  Then in the equation 
for normally \int\limits _{-\infty}^{+\infty} instead use \int\limits 

2) Some old solutions to eliminating unwanted, black line segments which 
unfortunately failed for me this time in an OpenSUSE-11.3, Linux operating 
system using LaTeX2HTML Version 2008 (1.71):

a) In the file /usr/lib/latex2html/l2hconf.pm with the line $DVIPSOPT 
.=" -Pdpf" already commented out with a # in front of it, as suggested by 
Shigeharu Takeno in at least August of 2009, also commenting out the line 
$DVIPSOPT = ' -Ppdf -E';    .

b) Running eqnfix.sh from http://www.vyvy.org/main/en/node/102 on the 
Internet with a command like this: "./eqnfix.sh Directory" in the directory 
above "Directory" to generate new and/or fixed .png images in the directory 
called "Directory."

I think that probably each of these methods "a" and "b" was successful in 
eliminating some undesired, vertical, black line segments in .png images in 
the year 2009 for me in an openSuSE-11.1 Linux operating system using 
probably LaTeX2HTML 1.70.

3) I experimented with using small font sizes for the limits of integration 
of positive and negative infinity, like for example this: \int\limits 
$-\infty$}}^{\mbox{\fontsize{1}{1}\selectfont $+\infty$}}.  But doing that 
did not eliminate the unwanted black line segment underneath the integral 
sign.  However, interestingly changing the upper limit to a digit like 0 or 
1 did eliminate the unwanted black line segment under the integral sign. 
But having 0 as the upper limit of integration is not what one would 
normally want when the upper limit is supposed to be positive infinity.  One 
could probably write the equivalent of "-infinity integral to + infinity" 
instead as "-infinity integral to 0" minus "+infinity integral to 0".  But I 
would like to avoid eliminating the unwanted black line segments in that 
perhaps awkward-looking way.

4) It might be useful for some other people to try this experiment in a test 
LaTeX file called, say Test.tex:

\int\limits _{-\infty}^{\infty}

, and then to issue the commands "latex Test.tex" and "latex2html 
nonavigation -no_math -html version 3.2,math -split 0 Test.tex".  Then in 
the resulting output file Test.html if there is no unwanted black line 
segment under the resulting integral sign, please report to us the versions 
of the following software packages you used:

Netpbm (For example obtain its version via the command "netpbm -version" or 
"Netpbm -version" in a Linux operating system.)
dvips (Please look at the output after a latex2html command for the version 
of dvips you are using.)
LaTeX2HTML  (Please look at the output after a latex2html command for the 
version of LaTeX2HTML you are using.)

and what form of the command $DVIPSOPT... is uncommented out, if any, and 
what values there are for the commands $MATH_SCALE_FACTOR=... and 
$DISP_SCALE_FACTOR=..in your file l2hconf.pm, which in my OpenSUSE-11.3, 
Linux operating system appears in the directory /usr/lib/latex2html. 
Perhaps there is some modern combination of software in which the unwanted 
black line segment does not appear under the integral sign and its limits. 
Or else if someone has a working solution to avoid the problem of the 
unwanted horizontal line segment, I would like to know what it is and what 
the details of your software environment are.


From: "Pat Somerville" <l_pat_s at hotmail.com>
Sent: Tuesday, April 12, 2011 12:24 AM
To: <latex2html at tug.org>
Subject: Re: [l2h] Black bars under integral signs when the limitsofintegrationare -\infty and +\infty or an algebraicfraction	for each of the upper and 
lower limits

> Thanks, JOS, for kindly taking the time to reply to me.  Did you find your
> workaround solutions to eliminate unwanted black line segments to work in 
> a
> version of LaTeX2HTML different from the one I am using?  I tried the two
> workaround solutions you mentioned with LaTeX2HTML Version 2008 (1.71):
> 1) $DVIPSOPT = ' '; in the file /usr/lib/latex2html/l2hconf.pm in place of
> $DVIPSOPT .= " -E";              ;
> 2) Including the line "transform round exch round exch itransform" right
> after the line "gsave newpath" in the file
> /usr/lib/texmf/dvips/config/alt-rule.pro [The path for the file 
> alt-rule.pro
> is slightly different in LaTeX2HTML Version 2008 (1.71) than the path
> mentioned within the version of the file alt-rule.pro replacing 
> alt-rule.pro
> in LaTeX2HTML Version 2008 (1.71).].
> And for the tests I returned to "$MATH_SCALE_FACTOR=1.6;", without the
> double quotation marks, within the file /usr/lib/latex2html/l2hconf.pm. 
> But
> unfortunately in my case the workaround 1 and the combination of the
> workarounds 1 and 2 did not remove the unwanted black line segment
> underneath an integral sign in the .html file produced by a latex2html
> command working with the .tex file containing the LaTeX command 
> \int\limits
> _{-\infty}^{+\infty} within an equation environment.  I also tried single
> quotation marks or apostrophes in place of double quotation marks in the
> line $DVIPSOPT = " -E"; in the file l2hconf.pm; but still the unwanted 
> black
> line segments remained within the produced .html file.   So I still 
> request
> help to remove the unwanted black line segments underneath some of my
> integral signs.
> Pat
> --------------------------------------------------
> From: "jos" <j at w3k.org>
> Sent: Monday, April 11, 2011 5:02 PM
> To: "Pat Somerville" <l_pat_s at hotmail.com>
> Cc: <latex2html at tug.org>
> Subject: Re: [l2h] Black bars under integral signs when the limits 
> ofintegrationare -\infty and +\infty or an algebraic fraction for  each of 
> the upper and
> lower limits
>> Here is how I got around the black-bar problem:
>> https://ccrma.stanford.edu/~jos/webpub/Eliminating_Black_Rules_Equation.html
>> - jos
>> At 12:15 PM 4/11/2011, Pat Somerville wrote:
>>>Thanks, Nasser M. Abbasi, for kindly taking the time to reply to me.  I
>>>found the file /usr/lib/latex2html/l2hconf.pm.  In it among other lines
>>>the following lines existed, but not necessarily consecutively:
>>>$DVIPSOPT .=" -E"; (Please notice the period before the equals sign.)
>>>So after receiving your e-mail letter I changed two of those lines to
>>>Results in the .html file produced by LaTeX2HTML: The black line segment
>>>under the integral sign with the limits of integration having algebraic
>>>fractions in them was removed.  But the black line segments under 
>>>signs produced from the LaTeX commands containing \int\limits
>>>_{-\infty}^{+\infty} remained.  Those were probably among 27 reported
>>>errors on 27 images.  I don't know with which images all of the other
>>>errors were. But I think I remember at least one pnmcrop-related error
>>>while latex2html was processing my .tex file.
>>>Next I changed to $MATH_SCALE_FACTOR=2.0; in the file l2hconf.pm and
>>>otherwise did not change any other lines in that file.
>>>Results: There were errors on 27 images.  The black segment under the
>>>integral sign with algebraic fractional limits returned.
>>>Continuing with the same settings in l2hconf.pm I made a test, .tex file
>>>containing some commands very similar to
>>>\int\limits _{-\infty}^{+\infty}
>>>and then produced a .html file from that .tex file using a latex2html...
>>>command.  In the resulting .html file a black line segment existed under
>>>the integral sign with the limits of positive and negative infinity. 
>>>should I do now to try to eliminate the unwanted black line segments 
>>>some of the integral signs?  Note also that there were also around 20
>>>images with errors reported while latex2html attempted to generate them;
>>>and in detail I don't yet know what obvious problems there were, if any,
>>>with the associated mathematical symbols associated with the images for
>>>which errors were reported by LaTeX2HTML.
>>>From: "Nasser M. Abbasi" <nma at 12000.org>
>>>Sent: Monday, April 11, 2011 1:37 AM
>>>To: <latex2html at tug.org>
>>>Subject: Re: [l2h] Black bars under integral signs when the limits
>>>ofintegrationare -\infty and +\infty or an algebraic fraction        for
>>>each of the upper and lower limits
>>>>On 4/10/2011 10:29 PM, Pat Somerville wrote:
>>>>>Question: What can I do to eliminate all of such examples of unwanted
>>>>>black bars
>>>>>  underneath some of the integral signs?
>>>>This sounds like the same known problem which was mentioned here some
>>>>time ago?
>>>>Check  http://12000.org/my_notes/l2hwin/index.htm  and look for
>>>>item (2) under "some errors and possible solutions"
>>>>Here it is:
>>>>"some of the bitmap images produced for the mathematics in the
>>>>document have a solid dark bar, usually at the bottom or the
>>>>side of the bitmap image. The reason for this is unknown.
>>>>But I found by trial and error that setting the following
>>>>values in my l2hconf.pm eliminated most if not all of these
>>>>Something to try to see if it will fix your problem.
>>>>latex2html mailing list
>>>>latex2html at tug.org
>>>latex2html mailing list
>>>latex2html at tug.org
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