Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 2.702756e-08.

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pankti Patel 2020-4-5

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评论： Christine Tobler 2020-4-8

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hello all

I am using pcregrigid and i am getting this warning.I fell this may detoriate my reconstruction result.

" Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 2.624234e-08.

In pcregrigid>pointToPlaneMetric (line 466)

In pcregrigid (line 253)

In Finalpointcloudstitchingwiththebust (line 27) "

This are the following code in the difffernt lines

--> In pcregrigid>pointToPlaneMetric (line 466)

line 466 X = C\b;

cx = cos(X(1));

cy = cos(X(2));

cz = cos(X(3));

sx = sin(X(1));

sy = sin(X(2));

sz = sin(X(3));

R = [cy*cz, sx*sy*cz-cx*sz, cx*sy*cz+sx*sz;

cy*sz, cx*cz+sx*sy*sz, cx*sy*sz-sx*cz;

-sy, sx*cy, cx*cy];

T = X(4:6);

---> In pcregrigid (line 253)

else % PointToPlane

line 253 [R, T] = pointToPlaneMetric(locA(inlierIndicesA, :), ...

ptCloudB.Location(inlierIndicesB, :), ptCloudB.Normal(inlierIndicesB, :));

end

--> In Finalpointcloudstitchingwiththebust (line 27)

line 27 [tform, ~, Err] = pcregrigid(moving, fixed, 'Metric','pointToPlane','Extrapolate', true);

Can anyone please help me ?

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Christine Tobler 2020-4-8

The warning is that the matrix C is badly conditioned, so the first question would be how C is constructed and what could cause it to be badly conditioned.

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Answer 1

Harshendra Shah 2020-4-8

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编辑：Harshendra Shah 2020-4-8

This warning message can occur when solving a linear system using the backslash operator (\). They indicate that the system being solved may be poorly conditioned or rank deficient; this can produce incorrect answers. In general the solutions you'll receive are correct, but if you receive these messages it's a good idea to check your results.

Problems with poor conditioning are generally a result of using double-precision arithmetic; you can find more useful information on double-precision arrays here:

https://www.mathworks.com/help/matlab/ref/double.html

Also, if you wish to ignore these warning messages, you can turn the warning indicator by typing ' warning off ' at the MATLAB command prompt. Alternatively, if you do not want to turn these warnings off entirely, you can use the command 'warning on', which will give shorter warning messages.

I hope this helps.