Hi Marco, the dateplot is a method to convert string-based date formats (YYYY-MM-DD) to numbers. Since you already have the result of such a transformation, you can safely use your numerical data (column 'datenum') -- and use the string-based time as tick labels.
An example could be \documentclass{article} \usepackage{pgfplots} \pgfplotsset{compat=1.3} \begin{document} \begin{tikzpicture} \begin{axis}[ xlabel=Time (MM:SS.sss), ylabel=Wat lev, xtick=data, xticklabels={ 00:00.000, 00:00.150, 00:00.230, 00:00.310, 00:00.470, 00:00.550, 00:00.630, 00:00.710, 00:00.870, 00:00.950, 00:01.030, 00:01.110 }, scaled x ticks=false, xticklabel style={anchor=east,rotate=90}, ] \addplot table[x=Time,y=WatLev_m] { Time TimeMM:ss.sss WatLev_m 0.0000000000000000000 00:00.000 0.00000 0.0000017361016944051 00:00.150 0.00000 0.0000026620691642165 00:00.230 0.00010 0.0000035879202187061 00:00.310 0.00030 0.0000054398551583290 00:00.470 0.00110 0.0000063657062128186 00:00.550 0.00180 0.0000072916736826301 00:00.630 0.00270 0.0000082176411524415 00:00.710 0.00380 0.0000100694596767426 00:00.870 0.00660 0.0000109954271465540 00:00.950 0.00840 0.0000119212782010436 00:01.030 0.01030 0.0000128472456708550 00:01.110 0.01250 }; \end{axis} \end{tikzpicture} \end{document} compare the attached pdf. The important aspects of the example are "scaled x ticks=false" and the explicitly provided tick positions (xtick=data) combined with explicitly provided tick label texts (xticklabels). You might also be interested in the option 'xticklabels from table={ \table or filename }{ colname }' (compare the manual). This appears to be the simplest way to accomplish the task - maybe you should enrich your samples with additional ticks in-between (either by modifying your data table or simply by providing the tick positions + labels). Does this help you? Best regards Christian Am 01.02.2012 09:27, schrieb Miani, Marco: > > Hello. > > When trying to plot my data, and using PGF plots, I came across the > following issue: > > My data is a set of two columns (actually 3 but one is unimportant): > > - former is time (matLab’s) datenum temporal format. The time > resolution am considering here, is of the order of (milli)seconds. > > - latter is some value (say oscillations). > > What follows is an example of the input file: > > % Time (datenum) Time(MM:ss.sss) WatLev (m) > > 0.0000000000000000000 00:00.000 0.00000 > > 0.0000017361016944051 00:00.150 0.00000 > > 0.0000026620691642165 00:00.230 0.00010 > > 0.0000035879202187061 00:00.310 0.00030 > > 0.0000054398551583290 00:00.470 0.00110 > > 0.0000063657062128186 00:00.550 0.00180 > > 0.0000072916736826301 00:00.630 0.00270 > > 0.0000082176411524415 00:00.710 0.00380 > > 0.0000100694596767426 00:00.870 0.00660 > > 0.0000109954271465540 00:00.950 0.00840 > > 0.0000119212782010436 00:01.030 0.01030 > > 0.0000128472456708550 00:01.110 0.01250 > > Problem: > > DATEPLOT does not have sufficient precision when swallowing datenum > numbers (first column). > > > Solution?: > > My question is if somebody has already encountered this problem and > possibly solved it. > > Thanks > > Marco from Norderney, Germany > > > ------------------------------------------------------------------------------ > Keep Your Developer Skills Current with LearnDevNow! > The most comprehensive online learning library for Microsoft developers > is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, > Metro Style Apps, more. Free future releases when you subscribe now! > http://p.sf.net/sfu/learndevnow-d2d > > > _______________________________________________ > Pgfplots-features mailing list > Pgfplots-features@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/pgfplots-features ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Pgfplots-features mailing list Pgfplots-features@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pgfplots-features