Hi Fer Probably you got appraisal from many but still I want to congratulate you publicly on Zonwvlak. Perhaps the best appraisal was done by Harold Brandmaier who prepared the HTML manual for your program. After all e-mail is only e-mail and does not take that much time as the mentioned document.
How much time did you spend on your wonderful program? Of all that is accessible on the web certainly zonwvlak is the best. I appreciate the papers you wrote on the subject, I mean pages in English, Dutch is not that widely known. The program works fine for both hemispheres and for multiple orientations of the dial. Just testing this was quite a work. Trigonometric formulae may produce fantastic results when sign rules aren't followed strictly and it is really easy to make a mistake, especially in a computer program. Tracking such bugs is not easy, they do not have to surface early. Ages old drafting methods were safer from this point of view. Drawing a specific dial took some time, at least few days, and the designer during this time got touch and feel of his project. But using old methods you could have one dial in few days if not weeks and with zonwvlak you may have many dials in few minutes. All best Slawek - Slawek Grzechnik http://home.earthlink.net/~slawek/ 32 45.8' N, 117 02.4' W
