View source for Display of constraint results

[[Category:Analytica User Guide]]
<breadcrumbs>Analytica User Guide > Formatting Numbers, Tables, and Graphs > {{PAGENAME}}</breadcrumbs>

Constraint nodes are used in [[Analytica_Optimizer_Guide|Analytica Optimizer]] models (not usable in lower Editions of Analytica. The Definition of a Constraint is a comparison such as '''x+y <= z'''. 

When displaying the result of a constraint it evaluates and displays the result of the left-hand and right-hand side values, which it displays along with the comparison operator using the selected number format. For example, the constraint defined as
:<code>GetFract(Expenses,75%) <= GetFract(Revenue,25%)</code>

might show as a result as:
:<code>845.1 <= 12.3K</code>

Note that in a non-constraint node, the result of a comparison would display as a Boolean value, i.e., 0 or 1 (False or True).

When the constraint is violated the display is proceeded by <code>{!}</code>, e.g., 

<code>{!}28<=21</code>. 

This information can help you debug an optimization model by showing the actual values of each side of the constraint. If you select the '''Boolean '''number format, it doesn't show the comparison display but rather <code>True</code> is displayed when the constraint is satisfied, <code>False</code> when it is violated. Beware that the optimizer solver engines sometimes find solutions that are within an epsilon (tiny number) of satisfying each constraint, and may show the constraint result as <code>False</code> because the constraint is violated only by epsilon, even though the solver engine considers it satisfied.

==See Also==
<footer>Date formats / {{PAGENAME}} / Multiple formats in one table</footer>