Thomas Dickerson [Thu, 12 May 2022 18:28:41 +0000 (14:28 -0400)]
Repair sparse_matrix.hpp
Unclear why nobody has noticed for a decade that this code was just totally uncompilable. `SparseMatrix` does not have methods `Columns()` or `Rows()`, and `m_ppElements[i]` is a pointer so can't possibly have anything called with `.`.