Graphic Examples

Dyalog Ltd. is grateful for the graphics examples which have been provided by Causeway Graphical Systems

The RAIN examples are slightly modified versions of the functions supplied in the RAIN workspace and illustrate how Dyalog can generate graphical images dynamically for display in a Web page.

Instead of producing output on a Form (using function View), the modified functions render a PostScript output to a Bitmap - via a Metafile. They then generate a PNG or GIF byte stream using the MakePNG and MakeGIF methods of the Bitmap object. The result is transmitted to your browser using TCPSend in raw mode.

MakeGIF creates an uncompressed GIF image. The GIF compression algorithm (patented by Unisys Corporation) is subject to license and royalty payments and is therefore omitted. The GIF images are large but may be displayed by any Web browser.

MakePNG generates a PNG (Portable Network Graphics) image which is a modern standard, free of licensing issues, and superior to GIF in many respects. You can compare the 2 examples for yourself.

Please note that PNG is only supported by the latest versions of Microsoft Internet Explorer and NetScape and the PNG examples will not work with other browsers.

Rain Graphics examples