matlab - Dot product with huge vectors -


i facing following problem: have system of 160000 linear equations 160000 variables. going write 2 programs on conjugate gradient method , steepest descent method solve it. matrix block tridiagonal 5 non 0 diagonals, it's not necessary create , store matrix. having following problem: when go iterarion stepe, there must dot product of vectors involved. have tried following commands: dot(u,v), u'*v, commonly used. when run program, matlab told me data size large memory.

to resolve problem, tried decompose huge vector sparse vectors small support, calculate dot products of small vectors , glue them together. seems method more complicated , not efficient, , easy (especially beginners me) make mistakes. wonder if there're more efficient ways deal problem. in advance.


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