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Happy new year to all.
Before I forget, I want to thank everyone who replied about the 2D angle
calculation problem. I have collated all the responses here:
http://guardian.curtin.edu.au/cga/faq/2Dangles.html
With the risk of offending everyone else, I am going to give my prize to
Zia Hasan, who came up with the following very simple algorithm:
IF x not equal to zero THEN angle = ATN(y/x) ELSE angle = SGN(y) * pi /
2
IF x < 0 THEN angle = angle + pi
IF angle < 0 THEN angle = angle +2*pi
I have checked this out for angles from 0 to 315 in steps of 45 degrees
in this little Excel spreadsheet:
http://guardian.curtin.edu.au/cga/faq/2Dangles.xls
As you can see, it works nicely. This might be a nice addition to the
ISB Software Archive.
Thanks again to everyone, and especially to Zia!
Chris
--
Dr. Chris Kirtley MD PhD
Associate Professor
Dept. of Biomedical Engineering
Catholic University of America
620 Michigan Ave NE, Washington, DC 20064
Tel. 202-319-6247, fax 202-319-4287
Email: kirtley@cua.edu
http://engineering.cua.edu/biomedical/faculty/kirtley
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Before I forget, I want to thank everyone who replied about the 2D angle
calculation problem. I have collated all the responses here:
http://guardian.curtin.edu.au/cga/faq/2Dangles.html
With the risk of offending everyone else, I am going to give my prize to
Zia Hasan, who came up with the following very simple algorithm:
IF x not equal to zero THEN angle = ATN(y/x) ELSE angle = SGN(y) * pi /
2
IF x < 0 THEN angle = angle + pi
IF angle < 0 THEN angle = angle +2*pi
I have checked this out for angles from 0 to 315 in steps of 45 degrees
in this little Excel spreadsheet:
http://guardian.curtin.edu.au/cga/faq/2Dangles.xls
As you can see, it works nicely. This might be a nice addition to the
ISB Software Archive.
Thanks again to everyone, and especially to Zia!
Chris
--
Dr. Chris Kirtley MD PhD
Associate Professor
Dept. of Biomedical Engineering
Catholic University of America
620 Michigan Ave NE, Washington, DC 20064
Tel. 202-319-6247, fax 202-319-4287
Email: kirtley@cua.edu
http://engineering.cua.edu/biomedical/faculty/kirtley
---------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l
---------------------------------------------------------------