概述

英文帮助文件(The program THE DISTRIBUTED FILES JKGRAPH OVERVIEW)

界面情况

概述

JKGRAPH是和WINPLOT齐名的电脑函数绘图软件。只能做二维的，但是可以进行极值、积分计算等复杂的分析方法。

英文帮助文件

The program

The program called JKGRAPH is a Microsoft WINDOWS program for graphing and

analyzing graphs of various kinds of functions that students are likely to

encounter in a math class. It is also a useful tool for teachers to create

graphs that can be imported into WINDOWS word processing documents. The

math level ranges from precalculus through the first year of calculus. An

overview of the program's capabilities is included in this file following the

descriptions of the distributed files.

THE DISTRIBUTED FILES

=====================

The following describe the contents of the file JKGRAPH.ZIP which contains

the distribution files for the program named JKGRAPH.

Filename Description

----------- --------------------------------------------------------------

JKGRAPH.EXE This is the executable file that is the JKGRAPH program.

JKGRAPH.HLP This is the WINDOWS on-line help file for JKGRAPH.

JKGRAPH.ICO This is the icon file for the JKGRAPH program.

JKGTUT .WRI This is a tutorial file in Microsoft WRITE format.

HELP .TXT This is the text file you are now reading.

You should at least read the document file JKGTUT.WRI before running the

JKGRAPH program for the first time. In fact, it is best to simply print

the file JKGTUT.WRI so you can read from the paper copy while you view the

output on your computer screen. JKGTUT.WRI is a tutorial file that takes

you through the beginning steps of using the program. It is especially

useful for first-time users of the program. JKGTUT.WRI is in the Microsoft

WRITE format which is the word processor that accompanies WINDOWS 3.1. If

you have WINDOWS 95 you can also print this document using the program called

WORDPAD that replaces Microsoft WRITE. In fact, you should be able to import

the file JKGTUT.WRI into any word processor that imports Microsoft WRITE

files. Microsoft WORD for WINDOWS can also import this file.

Another source of information is the WINDOWS on-line help file for JKGRAPH.

This help file contains an overview of the program as well as detailed

sections on all the menu items and all the dialog boxes. It also has a list

of special topics.

JKGRAPH Version 1.0 is a fully functioning program except for the features

using WINDOWS Metafiles because Microsoft has changed the Metafile format to

a new format that is in WINDOWS 95 called Enhanced Metafiles. As soon as

this file format is fully supported in Borland's DELPHI compiler a newer

version of JKGRAPH will be released. The new version may not be available

until early 1996, but at least you can expect that enhanced metafiles will

be supported at some time in the future. The next version will probably also

be specifically written for WINDOWS 95.

JKGRAPH OVERVIEW

================

The program called JKGRAPH is used to graph and analyze 2-dimensional

function curves. By a function curve we mean any graph that can be made

using standard rectangular functions or polar function curves or any other

curve given in a parametric form. Thus we use the term function as a synonym

for any 2D curve that can be described using piecewise continuous formulas.

Curves such as ellipses, hyperbolas and cardioids may not be functions

according to the strict mathematical definition of a function. We allow an

x-coordinate to determine more than one y-coordinate. The next few paragraphs

outline the operations you can perform on various function curves and serve

as a summary of the capabilities of the JKGRAPH program.

JKGRAPH uses four distinct function groups which include standard rectangular

functions in the form Y=F(X), polar functions in the form R=F(@), parametric

functions in the form X=F(T) and Y=G(T), and polar parametrized functions in

the form R=F(T) and @=G(T). Note that we use the variable T for time in

parametric formulas. We also use the special character @ to represent any

angle associated with polar coordinates. Think of using @ for angles because

this is the ASCII character symbol that comes closest to matching any of the

Greek letters alpha, or phi, or theta that would normally be used to denote

angles.

The graphics features of JKGRAPH are quite general. You can view any

rectangular portion of the XY-plane and you can easily perform zooming

operations. You can control individual graph curve attributes which include

colors and line thickness. You can also select from among 8 different

background grids which include combinations of the standard XY-axes,

polar-coordinate axes, and an XY-lattice line-grid. All the background

elements may be scaled and colored to change their appearance. You can also

select colors for any filled region, including the entire graph background.

You can copy any graph to the clipboard in a color bitmap format in which you

specify both the size of the graph in inches and the resolution in terms of

the number of pixels per inch. Thus JKGRAPH can be used to make color graphs

that can be imported into other Windows applications. In particular, JKGRAPH

makes it a breeze to create graphs and other tables that can be incorporated

into the scientific word processor called EXP. This is one of the major

reasons why the author of JKGRAPH decided to write the program.

Within each function group you can work with two independent curves or you

can link the two curves and then perform special operations such as finding

points of intersection or integrating to find the area between two curves.

Once a curve (or curves) have been entered you can analyze the curves.

JKGRAPH provides four trace modes with the names Coordinate Trace Mode, Graph

Trace Mode, Tangent Line Trace Mode, and Normal Line Trace Mode. In each

mode you can drag the mouse cursor across the screen and dynamically see

graphic elements and other information related to the trace position.

JKGRAPH can also perform special animated actions on function curves.

Included are operations for automatically finding maxima and minima points on

a curve or automatically finding multiple intersection points between two

curves. These features operate on all four function groups including polar

and parametrized curves.

For ordinary Y=F(X) function curves you can apply either Newtons Method or

the Method of Successive Bisections to find the x-intercepts. Both of these

methods can show an animated action and can create tables of values that are

generated during the processes. The table information is easily copied to

the Windows clipboard

You can also apply several integration techniques to any curve. For

rectangular functions there are 11 different integration techniques which

include lower, upper and midpoint Riemann sums, the Trapezoid Rule, Simpson's

Rule, Gaussian Quadrature, the Romberg Algorithm, arc length and surface area

and volumes using either disks or washers or cylindrical shells. For polar

and parametric function types you can calculate areas and arc length.

JKGRAPH can also automatically graph the derivative or inverse of any

function curve.

界面情况

如图，为函数x*sinx的图形，以及积分情况。