# Optimal Approximation of Quadratic Interval Functions

 This WWW page requires a Java-capable browser (e.g., Netscape Navigator 2.0 or higher, Microsoft Internet Explorer, etc.). If you do not have a Java-capable browser, then you can still read about the algorithm. To test out the algorithm, just enter the coefficients of the upper and lower quadratic functions and click on the Graph button. You may then click on specific points on the graph to get more information about those points.

## Adding this Java Program to Other World Wide Web Pages

To add this Java program to your World Wide Web page, add the following lines at the desired location:
```<CENTER>
<TABLE BORDER=5>
<TR><TD><CENTER>
<APPLET code="IntApprox.class" width=500 height=400></APPLET>
</CENTER>
<TR><TD><CENTER><A HREF="IntApprox.java">View Source Code</A></CENTER>
</TABLE></CENTER>
```

## Modifying the Java Program's Default Behavior

The following is a list of parameters that can be modified by inserting
`<PARAM NAME=name VALUE="value">`
between the <APPLET> and </APPLET> tags:
 name value type description lower_c1 floating-point value The coefficient of the lower function y-(x) at x*x lower_c2 floating-point value The coefficient of the lower function y-(x) at x lower_c3 floating-point value The coefficient of the lower function y-(x) at 1 upper_c1 floating-point value The coefficient of the upper function y+(x) at x*x upper_c2 floating-point value The coefficient of the upper function y+(x) at x upper_c3 floating-point value The coefficient of the upper function y+(x) at 1 left_x floating-point value The left-most X coordinate to be displayed right_x floating-point value The right-most X coordinate to be displayed color_upr RGB color value of the form #rrggbb where rr, gg, bb are the red, green, and blue color components in hexadecimal The color of the upper quadratic function color_lwr RGB color value The color of the lower quadratic function color_uprapprox RGB color value The color of the upper approximator function color_lwrapprox RGB color value The color of the lower approximator function color_other RGB color value The color of parts of the graph not representing a function, such as the axes bgcolor RGB color value The background color of the drawing area canvas_width integer The width of the drawing canvas on which the functions will be drawn canvas_height integer The height of the drawing canvas on which the functions will be drawn show_quad flag If set, specifies that the quadratic functions should be shown on startup show_approx flag If set, specifies that the approximator functions should be shown on startup"}}; Back to the main menu of the Interval Computations website