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Rounding of floating numbers

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I am comparing testpoint locations layout-to-fixture. Some Via testpoints are not on a 1 mil grid, and the round function in allegro seems to work differently than our manufacturer's fixture software round function. example; Allegro: round(145.47) - result 145 Fixture: 145.47 gets rounded to 146 If I know anything about rounding it seems that the fixture number is rounded correctly. How can I get allegro to round a number like the Fixture example?


Originally posted in cdnusers.org by Geoffm
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  •  I recently ran into this problem when doing things like:

    int(0.3 / 0.025) which should equal 12 but was returning 11 because of the IEEE floating point standard used by SKILL.

    To fix this I did added a small number that did not affect the significant digits, but forced the number to be over the actual value if the stored floating point number was less than the actual number:

    int(0.3 / 0.025 + 0.00001) which now equals 12.

     I hope this saves someone time if anyone come across this same IEEE floating point standards issue.

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  •  I recently ran into this problem when doing things like:

    int(0.3 / 0.025) which should equal 12 but was returning 11 because of the IEEE floating point standard used by SKILL.

    To fix this I did added a small number that did not affect the significant digits, but forced the number to be over the actual value if the stored floating point number was less than the actual number:

    int(0.3 / 0.025 + 0.00001) which now equals 12.

     I hope this saves someone time if anyone come across this same IEEE floating point standards issue.

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