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.

View Source Code

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"}};

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