package affectors;

import main.Node;
import main.Globals;

/** Returns zero as the derivative; use to lock a Node at a constant level,
such as an initial condition that should persist indefinitely. Note that simply leaving
the affector region for a Node blank will accomplish the same thing.

<p> <b>Formula</b>
<br>dnodex/dt = 0

<p> <b>Parameters</b>
<br>No Parameters

<p> <b>Usage</b>
<code><font size = "3"><br>&nodex
<blockquote>    &NoChangeAff
</blockquote>
&endnodex</code></font>
*/
public class NoChangeAff extends Affector {

	static final String		desc = "Lock a Node at its present value";
	
	public NoChangeAff()	{}

	protected void setLabelsAndTypes()	{
		setDescriptions(this.desc, null, null);

		this.Type[GUI_CAPABLE] = 1;
		this.Type[CERTIFICATION] = Affector.RETURNS_DERIV;
		this.Type[MATHTYPE] = Affector.CC;
		this.Type[TERMTYPE] = Affector.CONVERSION;
	}
	
	public void setParameterNumbers(int [] param_nums) {} // no parameters
	
	public float getValue(Node which_node) {
		return 0.0f;
	}
}