PCC Uptagging Guidelines

WPSML Plotting Support

Chris Hector

Logictran, Inc.

Draft 1.1

September 16, 2005

Introduction

This document provides details on WPSML 2.0 support for plotting.

Revision History

Draft 1.0 / 07/13/2005 / · Initial draft
Draft 1.1 / 09/16/2005 / · Resolved handling of axis labels that use multiples of pi or e

Elements

The plotting elements in WPSML are described in this section – and specific examples are contained in the following Examples section.

Algorithmic Attribute Values

Plotting elements are most often used for algorithmic content, and therefore some attribute values can be algorithmic in nature. Where this occurs, the attribute values column will show the attribute type, followed by /CM indicating that this attribute can contain a Compact Math syntax which must be expanded to obtain the attribute value.

chart

The chart element is used for all plots. In TestGen exports, the chart element has no attributes and contains a single "plot-area" element.

plot-area

The plot-area element contains all of the instructions for generating a plot. It has two attributes, height and width which specify the size of the plot in pixels.

The plot-area must contain one or more axis elements, along with the plot data (series, series-formula, and composites.) The type of plot (polar, cartesian, line) is determined by the axis elements contained within the plot-area.

Attribute / Description / Values / Required /
height
width / Specifies the height and width in pixels of the plot-area / floating point / Y /

axis

The axis element defines the coordinate system for the plot. In a line plot, there will be a single axis, in Cartesian there are two (x and y) and in polar there is a single axis.

Attribute / Description / Values / Required /
class / The class attribute determines the axis type and can contain the values "x" – specifying the horizontal axis, "y" for the vertical axis and "r" for the polar axis. / x, y, r / Y /
arrow-start
arrow-end / Indicates whether starting and ending arrows should be displayed. / yes, no / N, no is default /
visible / Indicates whether the axis should be displayed. / yes, no / N, yes is default /
minimum / The minimum value for the plot as displayed / floating point (CM) / Y /
maximum / The maximum value for the plot as displayed / floating point (CM) / Y /
length / The length of the axis in pixels. This length only refers to the plottable portion of the axis (without arrowheads and other presentational components) and is used for scaling purposes. / floating point / Y /
name / A label for the axis / CDATA (CM) / N, default is no label /
logscale / Set to "yes" if this axis is log scale. / yes, no / N, no is default /

tick-marks

The tick-marks element defines the ticks that are displayed along the axis. They also specify any grid lines for the plot. There can be zero or more tick-marks elements within an axis.

Attribute / Description / Values / Required /
units / Specifies the number of units represented by each tick / floating point (CM) / Y /
position / Indicates the position of a single tick mark. tick-marks may contain a label sub-element with a specific label. / floating point (CM) / N /
labels / Specifies the number of units before a label is displayed. If omitted no labels are displayed. / floating point (CM) / N, default is no label. /
type / Specifies the tick mark type / inner,
outer,
cross,
none / N, default is cross /
grid-line / Specifies a grid line corresponding to this tick-mark / none,
continuous,
dashed,
dotted / N, default is none /

series

The series element defines a series of individual points by providing the coordinates of each point.

Attribute / Description / Values / Required /
name / Specifies a name for the series / CDATA / Y /
visible / Indicates whether the series should be displayed. / yes, no / N, yes is default /

series-formula

The series-formula element defines a plotted line by providing a formula.

Attribute / Description / Values / Required /
name / Specifies a name for the series-formula / CDATA / N /
visible / Indicates whether the series-formula should be displayed. / yes, no / N, yes is default /
domain-min / The minimum valid value for the domain of the function. . / floating point (CM) / N, negative infinity is the default /
domain-max / The maximum valid value for the domain of the function. .. / floating point (CM) / N, infinity is the default /
template / Specifies a template for the series-formula – this is the name of a predefined template (hyperbola, circle) / CDATA / N, no default /

composite

The composite element allows multiple series-formulas or composites to be AND'ed together.

Attribute / Description / Values / Required /
name / Specifies a name for the composite / CDATA / Y /
visible / Indicates whether the composite should be displayed. / yes, no / N, yes is default /

point

The point element describes a single plot point.

Attribute / Description / Values / Required /
x-coord / The x-coordinate location (line or cartesian plot) or the r value (polar plot) / CDATA (CM) / Y /
y-coord / The y-coordinate location (line or cartesian plot) or the theta value (polar plot) / CDATA (CM) / N /

Examples

Example 1 Simple Cartesian plot

<chart

<plot-area height="200" width="200">

<tick-marks grid-line="dotted fine" units="1" labels="1"/>

</axis>

<tick-marks grid-line="dotted fine" units="100" labels="1"/>

</axis>

<series-formula>

<eq/>

</series-formula>

</plot-area>

</chart>

series-formula contains a y=f(x) expression using compact math representations. The v11, v10 in the expression element would be replaced with the correct variables for the algorithmic plot.
The x axis is labeled "t", and the y axis is labeled "h".

Example 2 Simple Line plot with labeled points

<chart

<plot-area height="40" width="238">

<tick-marks units="1" labels="2"/>

</axis>

<label<xhtml:div>A</xhtml:div</label>

</point>

<label<xhtml:div>B</xhtml:div</label>

</point>

<label<xhtml:div>C</xhtml:div</label>

</point>

</series>

</plot-area>

</chart>

Example 3 Axis numbered in multiples of Pi

<chart

<plot-area height="200" width="200">

<tick-marks position="1.57080"<label<mathml:math>

<mathml:mfrac<mathml:mrow<mathml:mn>Π</mathml:mn</mathml:mrow>

<mathml:mrow<mathml:mn>2</mathml:mn</mathml:mrow>

</mathml:mfrac</mathml:math</label</tick-marks>

<tick-marks position="3.1416"<label>Π</label>

</tick-marks>

<tick-marks position="4.71238"<label<mathml:math>

<mathml:mfrac<mathml:mrow<mathml:mn>3Π</mathml:mn</mathml:mrow>

<mathml:mrow<mathml:mn>2</mathml:mn</mathml:mrow>

</mathml:mfrac</mathml:math</label</tick-marks>

</axis>

<series-formula>
<expression>y</expression>
<eq/>
<expression>v1*cos(pi/2)</expression>

</series-formula>

</plot-area>

</chart>

In problem 1-5, the labels on the axis are expressed in terms of fractions of pi. This is specified by providing the tick marks and labels explicitly. The position attribute of tick-marks specifies a location, and the label sub-element provides the corresponding label.

Example 4 axis with omitted portion

<axis class="y" minimum="450" maximum="600" ...

Notes:

In problem 1-4, the y axis has an omitted section.

The spelling of this is

<axis class="y" minimum="450" maximum="600" ...

Example 5 Composite plot

<series-formula>

<geq/>

</series-formula>

<series-formula>

<leq/>

</series-formula>

</composite>

Notes:

The plotting of a composite contains the AND'ed result of the two inequalities.

Composites can contain other composites.

Example 6 Polar plot

Example 6 Hyperbola plot

Note that the template attribute is only provided as a hint and is not required.