# Adjustment network without measurement on references points

Hello,

How does it work ?

It doesn't work. It is a numerical issue due to the 64bit limit of a double value. In Matlab, for instance, you get the following warning:

Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND =  9.628486e-18. 

However, Matlab is (also) able to invert the normal equation matrix. Like Matlab, JAG3D uses LAPACK for matrix operations. Thus, the obtained results are not serious...

regards
Micha

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applied-geodesy.org - OpenSource Least-Squares Adjustment Software for Geodetic Sciences