How to plot using pstricks(3) --- plot a data file

The second data plotting command is "\dataplot[parameters]{command}".

Before you use "\dataplot", you have to read the data in using either command "\savedata {command} [data]" or "\readdata {command} [datafile]". At this time someone may ask "dataplot have to take two steps to finish the thing which fileplot takes only one step. Is there the necessity of its existance?" The answer is "yes". Because if you reuse the data, the combination of "\readdata" and "\dataplot" is much faster as the data file is read only one time.


Now let us come to an example of "\dataplot".

\documentclass{article}
\usepackage{pstricks}
\usepackage{pst-plot}
\begin{document}
  \psset{xunit=2cm,yunit=1.5cm}
  \begin{pspicture}(-1.25,-1)(3.25,1.25)
    \savedata{\mydatasinexp}%
[{0.,0.},{0.05,0.456044},{0.1,0.761394},
{0.15,0.858552},{0.2,0.74447},{0.25,0.466091},
{0.3,0.104544},{0.35,-0.247193},{0.4,-0.5073},
{0.45,-0.623301},{0.5,-0.581617},{0.55,-0.407061},
{0.6,-0.153346},{0.65,0.112302},{0.7,0.32625},
{0.75,0.44308},{0.8,0.444547},{0.85,0.341285},
{0.9,0.167555},{0.95,-0.029064},{1.,-0.200134},
{1.05,-0.307839},{1.1,-0.332868},{1.15,-0.2772},
{1.2,-0.161613},{1.25,-0.0190015},{1.3,0.114509},
{1.35,0.208373},{1.4,0.244281},{1.45,0.219299},
{1.5,0.145099},{1.55,0.0438223},{1.6,-0.0581267},
{1.65,-0.136698},{1.7,-0.175631},{1.75,-0.169538},
{1.8,-0.124137},{1.85,-0.0538507},{1.9,0.0224169},
{1.95,0.0861526},{2.,0.123554},{2.05,0.128327},
{2.1,0.102454},{2.15,0.0549385},{2.2,-0.000980753},
{2.25,-0.0513478},{2.3,-0.0848411},
{2.35,-0.0951862},{2.4,-0.0821522},{2.45,-0.0510304},
{2.5,-0.0108641},{2.55,0.0280359},{2.6,0.0566379},
{2.65,0.0691928},{2.7,0.0642737},{2.75,0.0447009},
{2.8,0.0164738},{2.85,-0.012943},{2.9,-0.0365153},
{2.95,-0.0492533},{3.,-0.0491912},{3.05,-0.0375617},
{3.1,-0.0182016}]
    \readdata{\mydataexp}{dataexp.dat}
    \psaxes{->}(0,0)(0,-1)(3.25,1.25)
    \dataplot[plotstyle=curve,linecolor=red]
      {\mydatasinexp}
    \dataplot[plotstyle=dots,linecolor=blue,
      dotsize=2.5pt]{\mydatasinexp}
    \dataplot[plotstyle=curve,linecolor=cyan]
      {\mydataexp}
  \end{pspicture}
\end{document} 

And data file "mydataexp.dat" contains the following datas:

[{0.,1.},{0.05,0.951229},{0.1,0.904837},
{0.15,0.860708},{0.2,0.818731},{0.25,0.778801},
{0.3,0.740818},{0.35,0.704688},{0.4,0.67032},
{0.45,0.637628},{0.5,0.606531},{0.55,0.57695},
{0.6,0.548812},{0.65,0.522046},{0.7,0.496585},
{0.75,0.472367},{0.8,0.449329},{0.85,0.427415},
{0.9,0.40657},{0.95,0.386741},{1.,0.367879},
{1.05,0.349938},{1.1,0.332871},{1.15,0.316637},
{1.2,0.301194},{1.25,0.286505},{1.3,0.272532},
{1.35,0.25924},{1.4,0.246597},{1.45,0.23457},
{1.5,0.22313},{1.55,0.212248},{1.6,0.201897},
{1.65,0.19205},{1.7,0.182684},{1.75,0.173774},
{1.8,0.165299},{1.85,0.157237},{1.9,0.149569},
{1.95,0.142274},{2.,0.135335},{2.05,0.128735},
{2.1,0.122456},{2.15,0.116484},{2.2,0.110803},
{2.25,0.105399},{2.3,0.100259},{2.35,0.0953692},
{2.4,0.090718},{2.45,0.0862936},{2.5,0.082085},
{2.55,0.0780817},{2.6,0.0742736},{2.65,0.0706512},
{2.7,0.0672055},{2.75,0.0639279},{2.8,0.0608101},
{2.85,0.0578443},{2.9,0.0550232},{2.95,0.0523397},
{3.,0.0497871},{3.05,0.0473589},{3.1,0.0450492}]

The plotted picture looks like this one:

Fig.1 An example of dataplot

The last data plotting command is "\listplot[parameters]{list}". And it has a similar usage as "dataplot", so no example of this command is provided. When using this command data can only delimited by white space.

Files download: tex ps pdf

How to plot using pstricks(1)----plot a function

After the previous posts, now we have the ability to deal with the plotting problems using pstricks. And this time we will talk about how to plot a function using pstricks.

The command used to plot a function in pstricks is "\psplot{xmin}{xmax}{function}". "xmin" and "xmax" determine the plot range and "function" is the function to be plotted. "function" should be written in postscript code. Since this blog is not about postscript, how to write a function in postscript code will not be talked in detail, only when it is used some simple explanation will be given.

There are also some optional parameters to control the appearance of the plot. "plotstyle=line,polygon,dots,curve..." controls the plotstyle, "plotpoints=int" controls how many points be plotted and other parameters such as "showpoints", "linestyle", "linecolor", "dotstyle"... have the same meaning as we have talked before.

Now we come to some examples.

\documentclass{article}
\usepackage{pst-plot}
\usepackage{pstricks}
\begin{document}
  \begin{pspicture}*(-1,-1)(5.5,5.5)
    \psgrid[gridlabels=0,gridcolor=gray,
      subgridcolor=lightgray](0,0)(5,5)
    \psaxes{->}(0,0)(0,0)(5.5,5.5)
    \psplot[linecolor=blue,plotstyle=dots,
      plotpoints=15,dotstyle=x,dotsize=4pt]
      {0}{5}{x}
    \rput{45}(2.5,3){\color{blue}$y=x$}
    \psplot[linecolor=red,plotstyle=dots,
      plotpoints=15,dotstyle=+,dotsize=4pt]
      {0}{5}{x 2 exp 5 div} %(x^2)/5
    \psplot[linecolor=red,plotstyle=line]
      {0}{5}{x 2 exp 5 div} %(x^2)/5
    \rput{55}(4,2.25)
      {\color{red}$y=\frac{x^{2}}{5}$}
    \rput(0.25,5.25){$y$}
    \rput(5.25,0.25){$x$}
  \end{pspicture}
\end{document} 

2
Fig.1 An example of Psplot—Plot function y = x and y = x /5.

\documentclass{article}
\usepackage{pst-plot}
\usepackage{pstricks}
\begin{document}
  \begin{pspicture}*(-1.25,-1.25)(4.5,1.25)
    \psgrid[gridlabels=0,gridcolor=red,
      subgridcolor=green](0,-1)(4,1)
    \psaxes[labels=y,tickstyle=bottom]
      {->}(0,0)(0,-1.25)(4.5,1.25)
    \rput(0.25,1){$y$}
    \rput(4.25,0.25){$x$}
    \psset{xunit=0.0111cm} %xuni=4cm/360
    \psplot[plotstyle=curve,
      linecolor=blue]{0}{360}{x sin}
       %"x sin" is postscript code
       %with meaing sin(x)
    \psplot[plotstyle=curve,linecolor=brown,
      linestyle=dashed]{0}{360}{x cos}
       %"x cos" is postscript code
       %with meaing cos(x)
    \uput[-90](90,0){$\frac{\pi}{2}$}
    \uput[-90](180,0){\scriptsize $\pi$}
    \uput[-90](270,0){$\frac{3\pi}{2}$}
    \uput[-90](360,0){\scriptsize $2\pi$}
  \end{pspicture}
\end{document}

Fig.2 Another example of Psplot—Plot function y = sin(x) and y =
cos(x).

Files Dowload: tex ps pdf

Some basic graph objects in pstricks (4) ---- Curves

There are several commands for curve drawing in Pstricks. "\psbezier" draws a Bezier curve, "\parabola" draws a parabola, and "\pscurve", "psecurve", "psccurve" interpolate curves through the given points. In the following they will be introduced one by one.

Bezier curve is really a set of curves (Linear Bezier curve, Quadratic Bezier curve, Cubic bezier curve ...). The Bezier curve in Pstricks is cubic Bezier curve. And to to determine a cubic Bezier curve four control points are needed ("How to draw a cubic Bezier curve according to four given points" can be found in Wikipedia). So the complete form of "\psbezier" is "\psbezier [parameters] {arrowtype} (x0,y0)(x1,y1)(x2,y2),(x2,y3)".

"\parabola [parameters] {arrowtype} (x0,y0)(x1,y1)" draws a parabola with maximum or minimum (x1,y1) staring from (x0,y0).

"\pscurve [parameters] {arrowtype} (x1,y1)...(xn,yn)" interpolates an open curve through the given points. "\psecurve" is similar to "\pscurve" except that the curve is not extend to the first and last points. "\psccurve" draws a closed curve.

The curvature of a curve is controlled by the parameter "curvature".

Now we use these commands to draw several curves.

\documentclass{article}
\usepackage{pstricks}
\begin{document}
  \begin{pspicture}(5,5)
    \psset{showpoints=true}
    \psbezier[linecolor=green]
      (0,0)(0,3)(5,1)(5,5)
    \parabola[arrowsize=10pt]
      {->}(5,5)(2.5,0)
    \pscurve[linecolor=red]
      (0,4)(1.25,5)(2.5,4)(3.75,3)(5,4)
    \pscurve[linecolor=blue,
      curvature=0.5 0.1 0]
      (0,1)(1.25,0)(2.5,1)(3.75,2)(5,1)
    \psccurve[fillstyle=solid,
      fillcolor=yellow]
      (3,4)(4.5,4)(4.5,4.5)(3,4.5)
  \end{pspicture}
\end{document} 

Fig.1 Draw Curves using Pstricks

Files Download: tex ps pdf

Some basic graph objects in pstricks (1) ---- Dots

In this and the next few posts some basic graph objects will be introduced. And the first one to be talked is "dots".

Commands "\psdot[parameters](x1,y1)" and "\psdots[parameters](x1,y1)(x2,y2)...(xn,yn)" both draw dots on the canvas. The only difference is that the first one draw only one dot each time, while the second one can draw more than one.

What the dots looks like is depend on the parameters used. The most used parameters are "dotstyle","dotsize","linecolor","fillcolor". Dotstyle determine the style of the dots, for example "*" for a solid circle, "o" for a hollow circle, "x" for a x symbol,"square" for a square and so on. For a complete set of dotstyles you may refer to the official documents. The dotsize determine the size of the dots. The color of the dots is determined by linecolor. If the dots is with a hollow center, the center is colored with fillcolor except for dotstyle "diamond". There are also some other parameters, you can find them in the official document. And at last an example is shown below:

\documentclass{article}
\usepackage{pstricks}
\begin{document}
\begin{pspicture}(5,5)
  \psdot[linecolor=red,dotstyle=*,
    dotsize=24pt](1,4)
  \psdot[linecolor=blue,fillcolor=red,
  dotstyle=o,dotsize=24pt](1,3)
  \psdots[fillcolor=blue,dotstyle=square,
    dotsize=12pt](1,2)(2,2)(3,2)
  \psset{dotsize=24pt,linecolor=yellow}
  \psdots[dotstyle=x](2.5,4)
  \psdot[dotstyle=+](2.5,3)
\end{pspicture}
\end{document}   

The picture these code draw looks like this:

Fig.1 Draw dots using Pstricks

Files Download: tex ps pdf