Rank: 2352 based on 60 downloads (last 30 days) and 6 files submitted
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Ying Xiong

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Harvard University

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12 May 2014 Screenshot NLOBox A matlab toolbox for nonlinear optimization. Author: Ying Xiong optimization, computer vision, toolbox 8 0
13 Feb 2014 Screenshot PSBox A matlab toolbox for photometric stereo. Author: Ying Xiong computer vision, toolbox 22 0
10 Feb 2014 Screenshot QBox A matlab toolbox for quaternion and spatial rotation. Author: Ying Xiong mathematics, geometry, physics, computer vision, toolbox 7 0
06 Feb 2014 Screenshot NLLSBox A matlab toolbox for nonlinear least squares optimization. Author: Ying Xiong optimization, computer vision, toolbox 8 0
29 Jan 2014 Screenshot SHBox A matlab toolbox for spherical harmonics. Author: Ying Xiong mathematics, physics, computer vision, toolbox 11 2
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01 Aug 2014 SHBox A matlab toolbox for spherical harmonics. Author: Ying Xiong Ying

Hi Tiago,

Thanks a lot for your comments.

In this toolbox (and in most other Spherical Harmonics toolboxes), the theta is defined in (0,pi) and phi in (-pi,pi) or (0, 2pi), so that the (theta,phi) parametrize a point on the sphere. The theta=-pi/2 case is not well-defined, and based on Legendre formula it should have the same value as theta=pi/2, because P(cos(theta)) should produce the same value.

Again, the table for Y_1^1 you are looking at should only be valid for theta in (0,pi) range. It is the convention of this toolbox (and most other SH toolboxes).

Hope that helps.

31 Jul 2014 SHBox A matlab toolbox for spherical harmonics. Author: Ying Xiong Tiago Lobo

31 Jul 2014 SHBox A matlab toolbox for spherical harmonics. Author: Ying Xiong Tiago Lobo

Please, check your code for the following examples:

l=1, m=1, theta = pi/2, phi = 0;
l=1, m=1, theta = -pi2/, phi=0;

They should give you -0.3455 and +0.3455 (check the results with the table for the analytical expression for Y_1^1, if necessary).

I point this out, because every single implementation of Spherical harmonics on Matlab that I found online have the same error, and unfortunately it's not only for l=1. If you figure out how to fix it, please let me know.

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