## datavisualization problems

Help
Anonymous
2012-07-11
2013-05-29

• Anonymous
2012-07-11

Hello,

I am trying to use the datavisualization library of Tikz. Apparently after 1.5 days of reading I am still not able to use it :(

So I wanted to make a plot on some floating point data. Therefore I created a file like this:

byte mean
0 6.724512
1 6.791320
2 6.604600
3 6.683576
4 6.600800
5 6.729672
6 6.560568
…..

There was no way to load this using something like:

\begin{tikzpicture}
\datavisualization
data ;
\end{tikzpicture}

I kept getting the error:
! Package PGF Math Error: Sorry, an internal routine of the floating point unit
got an ill-formatted floating point number '. The unreadable part was near ''
..

See the PGF Math package documentation for explanation.
Type  H <return>  for immediate help.
…

l.12 …tor=\space, read from file=mean884.table];

Then I decided to create a file with the following data (from an example in the manual):
x, y, z
0, 0, 0
1, 1, 0
1, 1, 0.5
0, 1, 0.5

and this seemed to work, with a code like:

\datavisualization …
data ;

Then I changed the contents of the file to this:
x, y
0, 0

This started again to give the same error:

! Package PGF Math Error: Sorry, an internal routine of the floating point unit
got an ill-formatted floating point number '. The unreadable part was near ''
..

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

I am using the last build version:
http://www.texample.net/media/pgf/builds/pgfCVS2012-05-18_TDS.tgz

I tried the general Tikz examples and those were running fine.
However I don't manage to get this datavisualization module to work.

Please share your experiences with this or just let me know if I should go with something like pgfplot for now.

Thanks

• Ignasi
2012-07-12

I've never tested dv before your message and I've found same errors with cvs version. I use pgfplots without any problems. Here you have some example: http://www.texample.net/tikz/examples/pgfplots/, and the manual, of course, is also full of examples.

Ignasi

• Anonymous
2012-07-12

Thanks Ignasi.

However, I would like to know if there are people using datavisualization and what to do in order to get the best of it.

I've recently read a letter from Till Tantau about his effort in making the datavisualization part of TikZ functional, so that one doesn't need to use other libraries like pgfplots, which anyway work on top of TikZ:
http://old.nabble.com/Future-of-data-visualization-in-TikZ-PGF,-Was%3A-Re%3A-pgfplots%3A-Integration-into-PGF-p15709938.html

The advantage I see with datavisualization (if one manages to use it), is that you can then combine many aspects of tikz in place, and have access to that coordinate system. Whereas if you use pgfplots, then you cannot longer easily access stuff from Tikz (as mentioned in the pgfplots manual, they use a different logic coordinate system).