## Forum archive 2000-2006

### Lars Jensen - Extra backslashes with dvipng. A bug?

by Arnold Pizer -
Number of replies: 0
 Extra backslashes with dvipng. A bug? topic started 11/28/2002; 2:18:12 AMlast post 11/29/2002; 12:27:45 AM
 Lars Jensen - Extra backslashes with dvipng. A bug?  11/28/2002; 2:18:12 AM (reads: 922, responses: 2) What is the reason that images produced by dvipng sometimes includes unnecessary backslashes? One problem with such images is setStatistics3Estimates/ur_stt_3_5.pg. When viewed in typeset2 mode this problem has several extra backslashes showing that don't appear in either of the formatted-text or typeset modes. Several other problems have the same extra backslashes in typeset2 mode. Is this a bug in dvipng? Lars. <| Post or View Comments |>

 John Jones - Re: Extra backslashes with dvipng. A bug?  11/28/2002; 4:04:51 PM (reads: 1167, responses: 0) Hi Lars, I looked at problems from that set. They use $$\$$ to generate a space. When dvipng is asked to turn that into an image, it gets confused by the fact that the image is blank. Actually, I haven't tracked it down to the source -- the bug may be in gd, the underlying graphics library which makes the png images. I will see if I can get the dvipng maintainer to look at fixing this. In the meantime, it seems that this is not the best way to handle the original problem. That is, whoever wrote the problem wanted to insert a hard space, presumably for aesthetic reasons. Currently, this would be accomplished on the web page by creating a blank image and displaying it to create space. But, some browsers don't support transparent backgrounds in png's, so the result would not be particularly aesthetic after all. On the other hand, both latex and html have ways of creating hard spaces. A better approach would be to use \$SPACE, a WeBWorK macro for doing what is desired, and which changes its output to do the right thing in each mode. John <| Post or View Comments |>

 Lars Jensen - Re: Extra backslashes with dvipng. A bug?  11/29/2002; 12:27:45 AM (reads: 1161, responses: 0) Hi John, Thanks for explaining this. -Lars. <| Post or View Comments |>