<html> <head> <title>Siag - The Plotter</title> </head> <body> <h1>The Plotter</h1> Siag uses Gnuplot for plotting. Gnuplot is normally used interactively, that is, commands are entered on the command line. When used from Siag, however, Siag automatically produces data and command files which are then processed by Gnuplot, so that it is not necessary to learn any Gnuplot commands to produce graphs from Siag. <h2>Gnuplot Made Easy</h2> To produce a graph from Siag, do the following: <ol> <li>Set the block on the data you want to plot <li>Click on the plotting icon </ol> That's it. This will produce a graph using lines. If the top row in the block contains labels, these will automatically be used for tic marks on the x axis. If the leftmost column contains labels, these will automatically be used as titles for the graphs. Anything else is used as data with one dataset per line. <p> The Plot menu can be used to select other plot styles. These are available: <dl> <dt><b>Lines</b> <dd>Connects adjacent lines with points. <dt><b>Points</b> <dd>Displays a small symbol at each point. <dt><b>Linespoints</b> <dd>The linespoints style does both lines and points. <dt><b>Impulses</b> <dd>Displays a vertical line from the x axis to each point. <dt><b>Dots</b> <dd>Plots a tiny dot at each point. <dt><b>Steps</b> <dd>This style connects consecutive points with two line segments: the first from (x1,y1) to (x1,y2) and the second from (x1,y2) to (x2,y2). <dt><b>Boxes</b> <dd>The boxes style draws a box centered about the yaxis to the given y coordinate. </dl> <h2>Advanced Plotting</h2> <i>None of this is actually implemented yet. This only describes what I would eventually be able to do with Siag.</i> <p> The "Advanced" plotting mode is only for users who are familiar with Gnuplot and the inner workings of Siag. It provides the possibility to plot <i>anything</i> that Gnuplot can plot, including 3D plots and plots where different datasets use different styles. The cost of this flexibility is that the plotting commands have to be entered as text. <p> The description below comes from the on-line help in Gnuplot. While the numerous parameters may seem intimidating, reasonable defaults are available for everything. <dl> <dt><b>mode</b> <dd>The two primary plotting modes are 2D and 3D. <dt><b>title</b> <dd>A title of each plot appears in the key <dt><b>style</b> <dd>Plots may be displayed in one of eight styles: <dl> <dt><b>lines</b> <dd>Connects adjacent lines with points. <dt><b>points</b> <dd>Displays a small symbol at each point. <dt><b>linespoints</b> <dd>The linespoints style does both lines and points. <dt><b>impulses</b> <dd>Displays a vertical line from the x axis (or from the grid base for 3D plots) to each point. <dt><b>dots</b> <dd>Plots a tiny dot at each point. <dt><b>errorbars</b> <dd>The errorbars style is only relevant for 2D plotting. It is like points, except that a vertical error bar is also drawn from (x,ylow) to (x,yhigh). A tic mark is placed at the ends of the error bar. <dt><b>steps</b> <dd>This style connects consecutive points with two line segments: the first from (x1,y1) to (x1,y2) and the second from (x1,y2) to (x2,y2). <dt><b>boxes</b> <dd>The boxes style is only relevant to 2D plotting. It draws a box centered about the yaxis to the given y coordinate. <dt><b>boxerrorbars</b> <dd>This style is a combination is combination of the boxes and errorbars styles. </dl> <dt><b>labels</b> <dd>The x- and y-axis have lables. The x label is centered along the x axis and the position of the y label depends on the terminal. <dt><b>terminal</b> <dd>Selects the type of graphics device for which Gnuplot will produce output. <dt><b>output</b> <dd>Directs the display to the specified file or device. <dt><b>logscale</b> <dd>Log scaling may be set on the x, y, and z axes. Any combination of x, y and z axes may use log scaling. If the base is not set, 10 is assumed. <dt><b>tics</b> <dd>Fine control of the axis tic marks is possible. See the documentation that comes with Gnuplot for more on this. <dt><b>grid</b> <dd>If this is selected, a grid is drawn at the tic marks. <dt><b>time</b> <dd>If selected, the time and date of the plot is placed at the top or bottom of the left margin. The exact location is device dependent. <dt><b>size</b> <dd>Scales the displayed size of the plot. </dl> <hr> <address>Ulric Eriksson - January 1997 - ulric@siag.nu</address> </body> </html>
