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GCalc 2.0 Documentation
Functions and Input
GCalc graphs functions. To be more specific, GCalc graphs many types of
functions where the domain and range are (floating-point) real numbers.
The text field to the upper left is where the functions are entered.
After typing in the function, press the
Please note several things from these examples.
The following mathematical functions are currently implemented:
Also, keep in mind the following.
Graphing Screen and Tracing
If the trace feature is turned off, passing the mouse over the graphing screen will display the cursor's coordinates on the coordinate panel directly below the graphing screen. Double-clicking on the screen will center the graph at that point.
If the trace feature is on, the GCalc will trace the functions on the screen if you wave the cursor over it. Clicking on the screen will iterate through the functions. The traced point's coordinate will also be displayed in the coordinate panel. You will see that the "Box-Zoom" feature is disabled when the calculator is tracing.
There are several other buttons at the bottom of the screen. Many of them control the various features of the graph. You can turn on and off the axes, the scale ticks, and the grid. Also, you turn off the default behavior of GCalc that connects the various points it plots. In certain cases, this default has undesirable results, especially at discontinuities in a function.
Pressing the colored button (below the "Prev" button), a palette dialog will come up, allowing the user to select a different color. The selected color will be used for the next function entered. You can also change the default palette by double-clicking on a particular palette color. This will bring up another dialog which allows you to pick any arbitrary colors in the HSB (Hue/Saturation/Brigness) color space.
The color of a particular function is determined when it is drawn the first time. It can be changed through the Function Management dialog
There are five types of predefined zooms.
In addition to these
preprogrammed zooms, you can zoom in and out with respect to the
center of the screen with the "Zoom in" and "Zoom out" buttons. Under
these buttons are two numbers. XZoom signifies the magnitude of
the zoom (in or out) horizontally. YZoom denotes the magnitude
of the zoom vertically. A value of
And what graphing calculator is complete without the interface to set
the window dimentions? It is relatively self-explanatory.
A scale of
These window textfields will accept expression that do not contain
As mentioned before,
differentiation is implemented and available through the
Calculations and Some General Limits
All calculations are limited to about 15 significant digits.
(1.23456789012345 is a number with 15 significant digits.) Please
remember that the calculations are done in floating-point and is
susceptible to round-off errors. For example,
The overflow occurs at about 1.7x10308.
Also, GCalc can only work with real numbers.
Therefore, functions such as
Angle Measurements (Degree vs Radians)
GCalc's default angle measurement is in radians, but this behavior can be changed by selecting the checkbox labeled 'Degree'. Graph involving trignometric functions will instantly reflect the change. Also, changing the angle measurement type will affect the functionality of the Trigonometric Zoom button. Selecting the checkbox labeled 'Radian' will easily switch to radian mode.
As discussed in the Frequently Asked Questions, printing of Java applets directly is a next-to-impossible task. So, instead the common approach is to take a screenshot and print it through another application (such as Adobe Photoshop, Microsoft Paint, Word, etc.). To facilitate the process, GCalc incorporates a the "Graph Window" button. Pressing this button will cause a window to pop-up which contains only the current graphing screen in order to minimize the cropping one must do.
To include the trace crosshairs into the graphing window, press down on the mouse button for 2 or more seconds. Letting go of the mouse button will pop-up the Graph Window with the crosshairs.
On Windows, GCalc should run on Netscape Navigator 4.06+, Microsoft Internet Explorer 4.0+, or any web browser that fully supports Java 1.1 API. Usually, you can download a Java plugin for your browser.
|© Copyright 2011 Jiho Kim|