Group Hardesty

Group Description
Surface fitting problem for visualization, Sean Hardesty

Visualization of 3D structures in the earth

The Hardesty3 matrix is an interpolation matrix stacked above a
weighted Laplacian, to to fit a surface z(x,y) to a set of points
in R^3 subject to a smoothness constraint enforced via regularization.
Hardesty2 is a smaller version of this problem.

For the big matrix (Hardesty/Hardesty3), sparse QR (via SuiteSparseQR,
or SPQR) finds an R factor and a set of Householder vectors (Q.H) with
about 150 million nonzeros.  Sparse LU factorization (with UMFPACK
v5.7.1) sees very high fillin (about 2.5 billion nonzeros in L+U).

The Hardesty1 matrix is a simple discretization of a 2D biharmonic
operator with some Lagrange multiplier constraints used for smoothing.
Displaying all 3 collection matrices
Id Name Group Rows Cols Nonzeros Kind Date Download File
2832 Hardesty2 Hardesty 929,901 303,645 4,020,731 Computer Graphics/Vision Problem 2015 MATLAB Rutherford Boeing Matrix Market
2831 Hardesty1 Hardesty 938,905 938,905 12,143,314 Computer Graphics/Vision Problem 2013 MATLAB Rutherford Boeing Matrix Market
2833 Hardesty3 Hardesty 8,217,820 7,591,564 40,451,632 Computer Graphics/Vision Problem 2015 MATLAB Rutherford Boeing Matrix Market