• SJSU Singular Matrix Database
• Matrix group: Pereyra
• Click here for a description of the Pereyra group.
• Click here for a list of all matrices
• Click here for a list of all matrix groups

• Matrix: Pereyra/landmark
• Description: Matrix from Victor Pereyra, Stanford University
• download as a MATLAB mat-file, file size: 6 MB. Use SJget(537) or SJget('Pereyra/landmark') in MATLAB.
• download in Matrix Market format, file size: 14 MB.
• download in Rutherford/Boeing format, file size: 12 MB.

Routine svd from Matlab 7.6.0.324 (R2008a) used to calculate the singular values.   Matrix properties (click for a legend) number of rows 71,952 number of columns 2,704 structural full rank? no structural rank 2,673 numerical rank 2,671 dimension of the numerical null space 33 numerical rank / min(size(A)) 0.9878 Euclidean norm of A 5.6865 calculated singular value # 2671 5.5945e-008 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 6.3906e-011 calculated singular value # 2672 3.4237e-011 gap in the singular values at the numerical rank: singular value # 2671 / singular value # 2672 1634.1 calculated condition number 1.306e+017 condest -2 nonzeros 1,146,848 # of blocks from dmperm 5 # strongly connected comp. 32 explicit zero entries 4,384 nonzero pattern symmetry 0% numeric value symmetry 0% type real structure rectangular Cholesky candidate? no positive definite? no

 author V. Pereyra editor T. Davis date 2003 kind least squares problem 2D/3D problem? no SJid 537 UFid 903

 Ordering statistics: AMD METIS nnz(V) for QR, upper bound nnz(L) for LU 119,169,475 24,580,681 nnz(R) for QR, upper bound nnz(U) for LU 1,544,068 290,943

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 4384 explicit zero entries.

Maintained by Leslie Foster, last updated 24-Apr-2009.

Entries 5 through 14 in the table of matrix properties and the singular
value plot were created using SJsingular code. The other plots
and statistics are produced using utilities from the SuiteSparse package.
Matrix color plot pictures by cspy, a MATLAB function in the CSparse package.