Calling VSS Library Using (I,J,Value) Format
VSS Library consist of One Call: 1. VSS_IJV (Setup the Data Structure and Reordering,Factorization, For/Back Solve, Free Memory)
CALL VSS_IJV(NEQ,NCOEFF,AMAT,IROW,ICOL,RHS,ANS,IFLAG,J_POINTER)
IFLAG = 1 Preform Setup, Memory Allocation, Factorization IFLAG = 2 Preform Forward/Back Substitution IFLAG = 3 Free all VSS Allocated Memory
NEQ [I] : number of equations
NCOEFF [I] : number of non-zero coefficients
IROW [I] : row location of each coefficient [size NCOEFF]
ICOL [I] : column location of each coefficient [size NCOEFF]
AMAT [I] : coefficients in row format including diagonals [size NCOEFF]
RHS [I] : Right-Hand Side (Load vector) [size NEQ]
ANS [O] : Left-Hand Side (Solution) [size NEQ]
IFLAG [I] : Integer
J_POINTER [-] : WORKING VECTOR SIZE (100,2)
[I] Denotes Input
[O] Denotes Output
Example:
1 2 3 4 5 6
1 | 100 1 2 5 | | X1 | | 201 |
2 | 200 6 7 9 | | X2 | | 202 |
3 | 300 10 11 12 | | X3 | | 203 |
A = 4 | 400 13 14 | | X4 | = | 204 |
5 | 500 15 | | X5 | | 205 |
6 | 600 | | X6 | | 206 |
NUMBER OF EQUATIONS = 6
NUMBER OF COEFFICIENTS = 12
NEQ = 6
NCOEFF = 18
IROW = { 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5,6}
ICOL = { 1, 2, 3, 6, 2, 3, 4, 6, 3, 4, 5, 6, 4, 5, 6, 5, 6,6}
AMAT = { 100,1, 2, 5, 200, 6, 7, 9,300, 10,11,12,400, 13,14,500, 15,600}
RHS = { 201, 202, 203, 204, 205, 206}