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Fix Non Invertible Matrix Issue - Compute Flattening #1

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Description of the Issue:
Upon running the script_orbifold_sphere command, the following error occured (details below). The root cause was identified in the computeFlattening.m script, where the inverse of matrix M is multiplied by matrix rhs. Matrix M is not invertible, leading to the propagation of a NaN matrix x_lambda until the script fails at an assertion.

Matrix M:
size: 5328 x 5328
rank: 5320 (deficient)
determinant: NaN

Proposed Solution:
By using Tikhonov Regularization, the 0 values within Matrix M are shifted by a small constant (alpha : 1e-10) . This in turn fixes the rank deficiency problem and successfully runs the following 3 scripts

Verified Scripts:
1. script_orbifold_sphere
2. script_orbifold_disk
3. script_NOT_ORBIFOLD_spherical_tutte

Remaining Observations:
The calculated determinant of M still appears to be unstable even after regularization (Inf). However, the linear constraint checks defined in the script have passed.

Original Error Message:
Error_Message

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