DITA Resource Center

<equation-figure>

Use the <equation-figure> element to represent an equation that functions as form of figure or display. Display equations are intended to be numbered when numbering is desired.

Since the <equation-figure> element is specialized from <fig>, display equations can have titles, descriptions, figure groups, and all other figure components. The direct children of <equation-figure> can be the equation content itself (for example, <mathml> or an image reference), or it can be one or more <equation-block> elements, along with other elements allowed within <fig>, such as paragraphs.

When an <equation-figure> element has multiple direct child <mathml>, <image>, or <pre> elements, each child represents an alternative form of the equation. Processors are free to choose the form or forms that they use in deliverables. For example, if there is both an image and MathML markup, an HTML-generating processor could output both the image reference and the MathML with appropriate HTML @class or @id values to enable dynamic showing or hiding of one form or the other based on browser capability. All other direct-child elements of <equation-figure> are treated normally.

When the intent is to have equations combined with other commentary within an <equation-figure>, the recommended best practice is to use child <equation-block> elements to contain the equations and clearly distinguish them from the commentary.

Content models

See appendix for information about this element in OASIS document type shells.

Inheritance

+ topic/fig equation-d/equation-figure

Example

In the following example, the <equation-figure> element contains a title and MathML:

<equation-figure>
  <title>Display equation with a MathML container</title>
  <mathml>
    <m:math display='block'>
      <m:semantics>
        <m:mrow>
          <m:mfrac>
            <m:mrow>
              <m:mi>n</m:mi><m:mo>!</m:mo>
            </m:mrow>
            <m:mrow>
              <m:mi>r</m:mi><m:mo>!</m:mo><m:mrow><m:mo>(</m:mo>
                <m:mrow>
                  <m:mi>n</m:mi><m:mo>&#x2212;</m:mo><m:mi>r</m:mi>
                </m:mrow>
                <m:mo>)</m:mo></m:mrow><m:mo>!</m:mo>
            </m:mrow>
          </m:mfrac>         
        </m:mrow>
      </m:semantics>
    </m:math>
  </mathml>
</equation-figure>

In the following example, the <equation-figure> element contains a title and an <equation-block> element that contains MathML and commentary:

<equation-figure>
  <title>Display equation with a MathML container</title>
  <equation-block>
    <mathml>
      <m:math display='block'>
        <m:semantics>
          <m:mrow>
            <m:mfrac>
              <m:mrow>
                <m:mi>n</m:mi><m:mo>!</m:mo>
              </m:mrow>
              <m:mrow>
                <m:mi>r</m:mi><m:mo>!</m:mo><m:mrow><m:mo>(</m:mo>
                  <m:mrow>
                    <m:mi>n</m:mi><m:mo>&#x2212;</m:mo><m:mi>r</m:mi>
                  </m:mrow>
                  <m:mo>)</m:mo></m:mrow><m:mo>!</m:mo>
              </m:mrow>
            </m:mfrac>            
          </m:mrow>
        </m:semantics>
      </m:math>
    </mathml>
  </equation-block>
  <p>Where 
<equation-inline><mathml><m:math><m:mi>r</m:mi></m:math></mathml></equation-inline>
is greater than 1.</p>
</equation-figure>

Attributes

The following attributes are available on this element: Universal attribute group, Display attribute group, @outputclass, and @spectitle.

Was this page helpful?