MATLAB: How to calculate the angular error

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     The angular error ε is defined as the angular distance between the algorithm’s estimate of the light source (ee) and the true illuminant vector (el) in normalized
     ε= Cos -1(el . ee ) this is the formula for calculation of angular error
This is the formula for calculate the angular error please give the code for that
thanking you

Best Answer

Apparently you have two 3D vectors, each of unit magnitude, el and ee, and you wish to find the angle between them. One formula would be:
 e = acos(dot(el,ee));
which gives e in radians. Another formula is:
 e = atan2(norm(cross(el,ee)),dot(el,ee));
which also gives e in radians. Furthermore it doesn't require that el and ee have unit magnitude. It is more accurate when e is near 0 or pi where the 'acos' function suffers larger rounding errors.
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