Introduction of XYGrapher
XYGrapher is a plotter of scatter graph (XY chart), which is frequenlty used in science and engineering. It's a free, open-sourced software distributed under the GPL.
Data contained in text files are plotted. Having data conversion function with user-defined expression, this software would be useful particularly for ones who want to make graphs quickly without using a spreadsheet. Also, since the format of the graph configuration file (*.xyg) is documented, you can automatically show figures of the output of numerical analysises or measured values retrieved from a datalogger by creating configuration files from a program and by executing this software using a Windows API such as CreateProcess function(Delphi, C++Builder, Visual C++ etc) or Shell function(Visual Basic).
Basic features required for a XY plotter are supported:

- Nonlinear curve fitting with user defined function as well as regression analysis for linearizable functions such as linear, exponential, or logarithmic function.
- Drawing user defined functions, which are highly readable with parameters and brackets([ ], { })
- Cubic spline that interpolate data points smoothly can be applied
- Numbering of the horizontal axis can bedate format
- Contour map with gradation can also be made.
- Error bar and data labels that automatically locate themselves

Quick Processing

- Wizard-guided quick configuration by drug-dropping a datafile into the desktop icon.
- Auto-scaling of axises including decision whether linear or logarithmic scale
- Pasting data copied from spreadsheet is supported.

Presentation and Publishing Quality

- In the title and legend, you can set font iname, size, color, bold, italic, superscript, subscript for each letter.
- Rich decolations such as arrow, 3-D effected marker, or shadowed legend frames.
- In slide-show mode, you can display slides in full-screen one by one guided by slide program that you configure
- In exporting as a image to presentation software, black objects such as labels, frames, and curves are automatically turned into white, which style fit to dark slide, when navy background is selected.

Other key features:

- Data trimming which excludes errornous data.
- Auto refreshing that automatically sences the update of a datafile and reload it.
- Mathematical mode suitable for teaching and learning mathematics.
- Numerical integration of user-defined function or plotted data

[Advantages over XY-plotting of spreadseet]
[Advantages over chart component of programming languages]
This software is written in Borland Delphi ver.6