# [OS X TeX] Error in TikZ code hard to find

Don Green Dragon fergdc at Shaw.ca
Thu Nov 13 09:14:45 CET 2014

Hello George,

On 11Nov2014, at 7:03 PM, George Gratzer <gratzer at me.com> wrote:

> My experience is different. TikZ catches almost no errors except missing “;”.

Yes, it does miss those missing «;» guys. However, it catches much trickier errors than that. Of course, perhaps you do not record as many blunders as I do.  :-)

> Type only few lines, typeset.

In this case I had typed but a few lines — thought they were bulletproof. It was the error message that befuddled me. Ross Moore’s suggestion surprised me for the error was then identified as occurring in the TikZ code.

> I error, comment out new lines, and introduce them a line (or two, if necessary) at a time.
> Should save you hours of grief.

The instance that I related is the ONLY one I’ve experienced wherein an error in the TikZ code was caught but not  identified as occurring within the TikZ code. AND, I have established an impressive  compendium of 'TikZ code' errors.

> If your TikZ code is correct, it will be typeset correctly. Same with LaTeX.
> But TikZ is even worse than LaTeX.
>
> How bad: it cannot typeset the first introductory example in the TikZ manual…

What «first introductory» example is that? Examples, from Till’s manual that I’ve checked, work.

>> On Nov 11, 2014, at 6:40 PM, Don Green Dragon <fergdc at shaw.ca> wrote:
>>
>> Hello All,
>>
>> I hope the following will not be too trivial for the knowledgeable people on this list but possibly it will help someone who regularly creates graphics with the wonderful TikZ package.
>>
>> Was working on a document with three chapters and was revising certain parts of chapter 1, hence it was the only chapter whose source code was active.
>>
>> Decided to include another {tikzpicture} environment. It was very simple and short and I was confident that the code would work, so typeset. TeXShop replies with an error of the form
>>
>> .Chapters/Chapter1.tex: 5805: Undefined control sequence
>> \Generic error …
>> 					#4 \errhelp  \@err@ ...
>>
>> l. 5805 … y over the closed interval $[0 \,..\, p] >>$.
>>
>> I get those kind of messages all the time because I make careless mistakes in typing; e.g., type \em[h{. . .} instead of \emph{. . .}. Usually the error message identifies the offending control sequence, but in this case I could not figure out which string was the offender.
>>
>> By the way, I use  source code fragments of the form $[a \,..\, b]$ often and they had caused no problems in the past. I focused on what appeared to be the offending  $[0 \,..\, p]$.
>>
>> After a couple of hours of trying this and that, including a suspicion that TeXShop was acting badly and so  RESTART and SHUT DOWM were tried, and much more, which I will avoid relating. Here follows my error.
>>
>> In the code for {tikzpicture} I had written (not including the line number 5682)
>>
>> 5682 \path (7, 0.5) node[right[ {Picture of blah blah blah};
>>
>>
>> 5682 \path (7, 0.5) node[right] {Picture of blah blah blah};
>>
>> and it was that incorrect occurrence of [‘ that triggered the error that was reported about line 5805.
>>
>> I know! I should have checked the tikzpicture code right away since the attempt to typeset it resulted in strange’ behaviour. Usually, TikZ catches those sort of errors so you can track them down.
>>
>> That’s it.

don green dragon
fergdc at shaw.ca