Or just use the following query: IsOblique Best regards Mattias
-- Mattias Ericson, B.Sc.E.E. Omnisys Instruments AB Gruvgatan 8 SE-421 30 Va"stra Fro"lunda, SWEDEN Phone: +46 (0) 31 734 34 08 Fax: +46 (0) 31 734 34 29 E-mail: [EMAIL PROTECTED] Web: http://www.omnisys.se Bevan Weiss wrote: >----- Original Message ----- >From: "Mr. Zhang Yangtian" <[EMAIL PROTECTED]> >To: "Protel " <[EMAIL PROTECTED]> >Sent: Thursday, February 12, 2004 4:47 AM >Subject: [PEDA] What's wrong with my query language program > > > > >>I had write one line of query language in ProtelDXP as the following: >> >>IsTrack and ((ABS(X1-X2)-ABS(Y1-Y2))=0) >> >> Its target is to find out all the tracks with their lean at 45-degree or >> >> >135-degree. After the execution of the program, some tracks are found while >some tracks satisfied with the constrain are leaked. I guess that the reason >is the precision of floating point number calculation. So I change it to the >following format: > > >>IsTrack and ((ABS(X1-X2)-ABS(Y1-Y2)) between -1 and 1). >> >>But this time, strange things happen: the queried tracks are nearlly all >> >> >the tracks with 0 degree, not 45-degree or 135-degree. Who can tell me why. >Is it a bug of DXP? > > >>Thank you very much! >> >> > >Why are you using subtraction?? >surely it then matters what the absolute lengths of the track are... >Perhaps the following would work: >IsTrack and ((ABS(Y2 - Y1) / ABS (X2 - X1)) = 1) >(you could also use a trig function to make it more understandable >ie if available use (ARCTAN((ABS(Y2-Y1) / ABS(X2-X1)) = 45), the use of the >absolute values for both X and Y directions constrains the angle to the >upper right quadrant, ie angles between 0 and 90degrees. > >Bevan > > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
