Hi,
Actually you can use them in the list, you just can't use them as node
names (which my example relied on):
\documentclass{article}
\usepackage{tikz}
\begin{document}
\makeatletter
\def\pgfmathdeclarelist#1#2{%
\def\[email protected]@name{#1}%
\[email protected]@counta=0%
\[email protected]#2{\[email protected]}%
}%
\def\[email protected]#1{%
\ifx#1\[email protected]%
\expandafter\edef\csname [email protected]@\[email protected]@name
@length\endcsname{\the\[email protected]@counta}%
\else%
\advance\[email protected]@counta by1\relax%
\[email protected]{[email protected]@\[email protected]@name
@\the\[email protected]@counta}{#1}%
\expandafter\[email protected]%
\fi%
}
\def\pgfmathgetlistitem#1#2#3{\expandafter\let\expandafter#1\expandafter=\csname
[email protected]@#[email protected]#3\endcsname}
\def\pgfmathsetlistitem#1#2#3{%
\[email protected]{[email protected]@#[email protected]#2}{#3}%
}
\def\pgfmathgetlistlength#1#2{%
\expandafter\let\expandafter#1\expandafter=\csname
[email protected]@#[email protected]\endcsname%
}
\def\pgfmathknuthshuffle#1{%
\pgfmathgetlistlength\[email protected]{#1}%
\pgfmathloop%
\ifnum\pgfmathcounter>\[email protected]%
\else%
\pgfmathrandominteger\[email protected]{1}{\[email protected]}%
\pgfmathgetlistitem\[email protected]@temp{#1}{\pgfmathcounter}%
\pgfmathgetlistitem\[email protected]@@temp{#1}{\[email protected]}%
\def\[email protected]{\pgfmathsetlistitem{#1}}%
\expandafter\[email protected]\expandafter{\expandafter\[email protected]\expandafter}\expandafter{\[email protected]@temp}%
\expandafter\[email protected]\expandafter{\expandafter\pgfmathcounter\expandafter}\expandafter{\[email protected]@@temp}%
\repeatpgfmathloop%
}
\makeatother
\pgfmathdeclarelist{mylist}{{A}{\Huge B}{C}{lots of text
}{E}{F}{$\frac{2}{7}$}{H}{I}{J}{K}{L}{$\sqrt{2}$}}
\pgfmathgetlistlength{\l}{mylist}
\foreach \i in {1,...,\l}{
\pgfmathgetlistitem{\x}{mylist}{\i}
\typeout{mylist[\i]=\x}
}
\typeout{Shuffling}
\pgfmathknuthshuffle{mylist}
\foreach \i in {1,...,\l}{
\pgfmathgetlistitem{\x}{mylist}{\i}
\typeout{mylist[\i]=\x}
}
\end{document}
It's possible to define safe labels (ie aliases) for list items and
then sort the labels, and recall the items according to their labels.
A bit fiddley though.
Mark
2009/5/6 Matthew Leingang :
> Dear Mark,
>
> [Hope this isn't too off topic. Is there a pgfmathusers list?]
>
> Thanks for helping me clean that up. You're right; I should just use a
> separate class for lists.
>
> Your implementation has a flaw that mine also had. If I replace the
list
> declaration with
>
>
>
\pgfmathdeclarelist{mylist}{{A}{B}{C}{D}{E}{F}{G}{H}{I}{J}{K}{L}{$\sqrt{2}$}}
>
> I get
>
> ! Argument of \[email protected]@lor has an extra }.
>
> \par
> l.59 }
>
> Or if I change it to
>
>
>
\pgfmathdeclarelist{mylist}{{A}{B}{C}{D}{E}{F}{G}{H}{I}{J}{K}{L}{{$\frac{A}{B}$}}}
>
> I get
>
> ! Missing \endcsname inserted.
>
> \begingroup
> l.59 }
>
> With my implementation I could use \frac but not \sqrt.
>
> I'm guessing it's a movingarguments issue, but sprinkling \protect's in
> various places didn't have any effect. For my implementation, I was
able to
> workaround by saving the input into a box and inputing the box to the
list,
> as in:
>
> \newsavebox{\mybox}\savebox{\mybox}{$\frac{A}{B}$}
>
>
\pgfmathdeclarelist{mylist}{{A}{B}{C}{D}{E}{F}{G}{H}{I}{J}{K}{L}{\usebox{\mybox}}}
>
> But for yours, again I get the "Missing \endcsname inserted" error.
>
> I need to have math in my lists (these are multiple choices on an exam),
so
> I will look at our two code samples and see if I can merge them.
>
> Matt
>
>
> On May 6, 2009, at 7:19 AM, Mark Wibrow wrote:
>
>> Hi,
>>
>> I wouldn't try to use the random list stuff. Just implement a
>> different list structure and access it using random integers. The
>> following demonstrates the sort of thing that could do it:
>>
>> [...]
>>
>> 2009/5/4 Matthew Leingang :
>>>
>>> Hi,
>>>
>>> I'm just getting into the pgfmath package more. Good stuff!
>>>
>>> I'm writing an exam and would like to randomly permute the order of
>>> multiplechoice items. I was thinking of using the
>>> \pgfmathdeclarerandomlist command and then writing something to do a
>>> Knuth shuffle: for each i from 1 to n, choose a random number j from 1
>>> to n, then swap position i and j.
>>>
>>> Before I get too deep, has anyone done this or something like this
>>> before?
>>>
>>> TIA,
>>> Matt
>
> 
> Matthew Leingang
> Clinical Associate Professor of Mathematics
> [email protected]
>
>
>
>

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