Graph is an open source application used to draw mathematical graphs in a coordinate system. Anyone who wants to draw graphs of functions will find this program useful. The program makes it very easy to visualize a function and paste it into another program. It is also possible to do some mathematical calculations on the functions.


Why should you use Graph?
Here are some of the things Graph can do for you:

Draw functions
Graph can draw normal functions, parameter functions, and polar functions. You can use a lot of built-in functions, e.g. sin, cos, log, etc. You may specify color, width and line style of the graphs, and the graphs may me limited to an interval. It is also possible to show a circle at the ends indicating open or closed interval.

Draw relation
Graph can show any equation and inequality, for example sin(x) < cos(y) or x^2 + y^2 = 25. You can choose line width and color for the equations, and color and shading style for the inequalities.

Interact with other programs
You can save the coordinate system with graphs as an image on disk either as a bitmap (bmp), Potable Network Graphics (png), JPEG, metafile (emf) or Portable Document Format (PDF). You may also copy the coordinate system into another program, e.g. Microsoft Word, either as a normal image or as an OLE object, which may be edited later by double clicking on it.

A lot of options
While still easy to use Graph has a lot of customization possibilities, e.g. fonts, colors, axes style, grids, etc. The axes, which may by normal or logarithmic, can be placed either by entering specific values, or by moving or zooming with the mouse.

Given an x-coordinate Graph will calculate the function value and the first two derivatives for any given function. Alternatively the function may be traced with the mouse. Graph can also fill a table with evaluated function coordinates in a user specified range. Data from the table can easily be copied into another program, e.g. Microsoft Excel.

Graph can help you calculate the area under a function in a given interval and the distance along the curve between two points on the function. The program can also show the first derivative of a function, and create tangents and normal lines to a function at given coordinates.

Point series and trendlines
You can create series of points with different markers, colors and size. Data for a point series can be imported from other programs, e.g. Microsoft Excel. It is possible to create a line of best fit from the data in a point series, either from one of the built-in models or from a user specified model.

Shadings and labels
Graph can insert shadings used to mark an area related to a function. Shadings may be created with different styles and colors in a user specified interval. In addition to the optional legend used to describe each function, a label may be added anywhere in the system. A label can contain text with different fonts, images and objects created in other programs.

Custom functions
You can create your own custom functions and constants for use in functions, relations, etc. You can for example create a custom function sinc(x)= sin(x)/x and a constant R= 8.314510. You can when plot the function f(x)=R*sinc(x).
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With Graph you can trace a function with the mouse by clicking on the graph, or you can enter an x-coordinate for which you want the function evaluated. The program will then tell you the function value f(x) and the first two derivatives f'(x) and f''(x) evaluated at the given coordinate.

You can insert 6 different types of shadings to mark an area. This can for example be an area between a function and the x-axis, but other possibilities are also available. Of course the user can specify the exact limits of the area.

Any graph can be drawn by entering its function. To draw the function y=x*cos(x), you just enter "x*cos(x)". The program supports a lot of built in functions that can be used.

It is possible to add series of points to the coordinate system. The points are given by their x- and y-coordinates. The user can choose between different types of markers and lines between the markers.

Based on a series of points, the program can create 6 types of built-in trendlines and any kind of user defined function to match the points.

Formatted text labels can be added anyplace in the coordinate system.

Any equation and inequality can be drawn. You can for example draw a circle with radius 8 and center in (0,0) as the equation x^2 + y^2 = 64. A shaded circle with radius 3 and center in (5,5) can be draw as the inequality (x-5)^2 + (y-5)^2 < 9.

license F R E E
Requirements: Windows 95/98/Me/NT/2000/XP