Subsections

MA77 Linear Solver


ma77_print_level:

Debug printing level for the linear solver MA77
The valid range for this integer option is $ {\tt -inf} < {\tt ma77\_print\_level } < {\tt +inf}$ and its default value is $ -1$.


ma77_buffer_lpage:

Number of scalars per MA77 buffer page
Number of scalars per an in-core buffer in the out-of-core solver MA77. Must be at most ma77_file_size. The valid range for this integer option is $ 1 \le {\tt ma77\_buffer\_lpage } < {\tt +inf}$ and its default value is $ 4096$.


ma77_buffer_npage:

Number of pages that make up MA77 buffer
Number of pages of size buffer_lpage that exist in-core for the out-of-core solver MA77. The valid range for this integer option is $ 1 \le {\tt ma77\_buffer\_npage } < {\tt +inf}$ and its default value is $ 1600$.


ma77_file_size:

Target size of each temporary file for MA77, scalars per type
MA77 uses many temporary files, this option controls the size of each one. It is measured in the number of entries (int or double), NOT bytes. The valid range for this integer option is $ 1 \le {\tt ma77\_file\_size } < {\tt +inf}$ and its default value is $ 2097152$.


ma77_maxstore:

Maximum storage size for MA77 in-core mode
If greater than zero, the maximum size of factors stored in core before out-of-core mode is invoked. The valid range for this integer option is $ 0 \le {\tt ma77\_maxstore } < {\tt +inf}$ and its default value is 0.


ma77_nemin:

Node Amalgamation parameter
Two nodes in elimination tree are merged if result has fewer than ma77_nemin variables. The valid range for this integer option is $ 1 \le {\tt ma77\_nemin } < {\tt +inf}$ and its default value is $ 8$.


ma77_order:

Controls type of ordering used by HSL_MA77
This option controls ordering for the solver HSL_MA77. The default value for this string option is "metis".
Possible values:


ma77_small:

Zero Pivot Threshold
Any pivot less than ma77_small is treated as zero. The valid range for this real option is $ 0 \le {\tt ma77\_small } < {\tt +inf}$ and its default value is $ 1 \cdot 10^{-20}$.


ma77_static:

Static Pivoting Threshold
See MA77 documentation. Either ma77_static=0.0 or ma77_static>ma77_small. ma77_static=0.0 disables static pivoting. The valid range for this real option is $ 0 \le {\tt ma77\_static } < {\tt +inf}$ and its default value is 0.


ma77_u:

Pivoting Threshold
See MA77 documentation. The valid range for this real option is $ 0 \le {\tt ma77\_u } \le 0.5$ and its default value is $ 1 \cdot 10^{-08}$.


ma77_umax:

Maximum Pivoting Threshold
Maximum value to which u will be increased to improve quality. The valid range for this real option is $ 0 \le {\tt ma77\_umax } \le 0.5$ and its default value is $ 0.0001$.