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Gauss quadrature on triangle

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Old   May 9, 2012, 09:50
Default Gauss quadrature on triangle
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DJChoi
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Hello?

I want to do Gauss quadrature over triangle as attachted file.
I would like to know how to find the points and weights for Gauss quadrature.

Thanks.
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Old   May 10, 2012, 06:43
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Just map the triangle to a rectangle, and apply the 1d Gauss quadrature in a tensor product way!
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Old   May 10, 2012, 09:15
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Here are some quadrature rules

http://people.sc.fsu.edu/~jburkardt/.../dunavant.html

Also, check any good book on fem.
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Old   May 10, 2012, 09:23
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Look at http://people.sc.fsu.edu/~jburkardt/...rules_tri.html
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Old   May 10, 2012, 09:33
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Hi, cfdnewbie.

Thank you for your answer.
I know the mapping the triangle to a rectangle.
And I can apply the 1d Gauss quadrature.

But I don't know how to apply the 1d Gauss quadrature in a tensor product way.
Would you tell me the way how to do that, please ?
Or, would you recommend any book written that way, please ?

Last edited by effort8; May 10, 2012 at 09:54.
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Old   May 10, 2012, 09:40
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Hi, praveen. Hi, Jonas Holdeman praveen.

Thank-you for useful information about website.

One more question.
Would you tell me the transformation mapping from "(-1,-1),(1,-1),(-1,1)" to "(0,0), (1,0), (0,1)" ?

I would like to know the transformation mapping equation.

Last edited by effort8; May 10, 2012 at 09:57.
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Old   May 10, 2012, 11:19
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It is a simple scale and shift.
x=(1+q)/2, y=(1+r)/2, for q=+/- 1, r=+/- 1.
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Old   May 11, 2012, 01:03
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Hi, Jonas Holdeman
Thank-you for your answer.

Your answer is big help to me.
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