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
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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
>
>  
>




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