why does latex report errors when using styles in a tikz pgf picture?

Question

I get three errors when attempting to build the following example (with the tikzpicture taken from the tikz pgf manual). Why does this happen, and what am I doing wrong?

\documentclass[12pt]{article}

\usepackage{tikz}

\begin{document}

\begin{figure}

  \begin{tikzpicture}

    [Karl's grid/.style ={help lines,color=#1!50},
    Karl's grid/.default=blue]

    \draw[Karl's grid] (0,0) grid (1.5,2);

    \draw[Karl's grid=red] (2,0) grid (3.5,2);

  \end{tikzpicture}

\end{figure}

\end{document}

Here is some of the log including the errors:

[Loading MPS to PDF converter (version 2006.09.02).]
\scratchcounter=\count107
\scratchdimen=\dimen148
\scratchbox=\box35
\nofMPsegments=\count108
\nofMParguments=\count109
\everyMPshowfont=\toks24
\MPscratchCnt=\count110
\MPscratchDim=\dimen149
\MPnumerator=\count111
\everyMPtoPDFconversion=\toks25
)
Missing character: There is no [ in font nullfont!
Missing character: There is no K in font nullfont!
Missing character: There is no a in font nullfont!
Missing character: There is no r in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no ' in font nullfont!
Missing character: There is no s in font nullfont!
Missing character: There is no g in font nullfont!
Missing character: There is no r in font nullfont!
Missing character: There is no i in font nullfont!
Missing character: There is no d in font nullfont!
Missing character: There is no / in font nullfont!
Missing character: There is no . in font nullfont!
Missing character: There is no s in font nullfont!
Missing character: There is no t in font nullfont!
Missing character: There is no y in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no e in font nullfont!
Missing character: There is no = in font nullfont!
Missing character: There is no h in font nullfont!
Missing character: There is no e in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no p in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no i in font nullfont!
Missing character: There is no n in font nullfont!
Missing character: There is no e in font nullfont!
Missing character: There is no s in font nullfont!
Missing character: There is no , in font nullfont!
Missing character: There is no c in font nullfont!
Missing character: There is no o in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no o in font nullfont!
Missing character: There is no r in font nullfont!
Missing character: There is no = in font nullfont!

! You can't use `macro parameter character #' in restricted horizontal mode.
l.24     [Karl's grid/.style ={help lines,color=#
                                                 1!50},
Sorry, but I'm not programmed to handle this case;
I'll just pretend that you didn't ask for it.
If you're in the wrong mode, you might be able to
return to the right one by typing `I}' or `I$' or `I\par'.

Missing character: There is no 1 in font nullfont!
Missing character: There is no ! in font nullfont!
Missing character: There is no 5 in font nullfont!
Missing character: There is no 0 in font nullfont!
Missing character: There is no , in font nullfont!
Missing character: There is no K in font nullfont!
Missing character: There is no a in font nullfont!
Missing character: There is no r in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no ' in font nullfont!
Missing character: There is no s in font nullfont!
Missing character: There is no g in font nullfont!
Missing character: There is no r in font nullfont!
Missing character: There is no i in font nullfont!
Missing character: There is no d in font nullfont!
Missing character: There is no / in font nullfont!
Missing character: There is no . in font nullfont!
Missing character: There is no d in font nullfont!
Missing character: There is no e in font nullfont!
Missing character: There is no f in font nullfont!
Missing character: There is no a in font nullfont!
Missing character: There is no u in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no t in font nullfont!
Missing character: There is no = in font nullfont!
Missing character: There is no b in font nullfont!
Missing character: There is no l in font nullfont!
Missing character: There is no u in font nullfont!
Missing character: There is no e in font nullfont!
Missing character: There is no ] in font nullfont!

! Package pgfkeys Error: I do not know the key '/tikz/Karl's grid' and I am goi
ng to ignore it. Perhaps you misspelled it.

See the pgfkeys package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.27     \draw[Karl's grid]
                            (0,0) grid (1.5,2);
This error message was generated by an \errmessage
command, so I can't give any explicit help.
Pretend that you're Hercule Poirot: Examine all clues,
and deduce the truth by order and method.


! Package pgfkeys Error: I do not know the key '/tikz/Karl's grid' and I am goi
ng to ignore it. Perhaps you misspelled it.

See the pgfkeys package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.29     \draw[Karl's grid=red]
                                (2,0) grid (3.5,2);
(That was another \errmessage.)

I'm using tikz 2010/10/13 v2.10 (rcs-revision 1.76), and am using MikTex on Windows XP in conjunction with Texniccenter.

score 14 · Accepted Answer · answered Jan 19 '12 at 10:29

14

The problem is caused by the empty line after you opened the tikzpicture environment. Note, that an empty line usually means a paragraph break, so don't use it in the document code just because of readability. If you would like to use (nearly) empty lines for separation, set at least a % into the line to comment it out.

It works this way:

\begin{tikzpicture}
  [Karl's grid/.style ={help lines,color=#1!50},
  Karl's grid/.default=blue]

answered Jan 19 '12 at 10:29

Stefan Kottwitz

231,401

1

@crobar Also if you look at the error message it spells out a part of your code vertically. This can help you in the future to see that something is at a place where it's not supposed to be. – percusse Jan 19 '12 at 10:59
@percusse I knew the error was first detected on the Karl's Grid line, but not what was causing it. – crobar Jan 19 '12 at 16:16
If you insert a % into the line, can it be indented or does it have to be in the beginning of the line (i.e. no space or tab before it)? – StrawberryFieldsForever Aug 21 '13 at 12:49
@StrawberryFieldsForever Good question. See my supplemental answer. – Jonathan Komar Sep 14 '16 at 09:16

score 2 · Answer 2 · answered Sep 14 '16 at 09:16

Supplemental Answer

\documentclass{article}
\begin{document}
\section{Test 1}
This new line:
will become a space in this statement.
\section{Test2}
This new line + empty line:

will become a new paragraph in this statement.
\section{Test 3}
This new line + non-indented \%:
%
will become a space in this statement.
\section{Test 4}
This new line + indented \%:
   %
will become a space in this statement.
\end{document}

why does latex report errors when using styles in a tikz pgf picture?

2 Answers2

Supplemental Answer

Linked