, 50 min read

Stability Mountains for Varah 7-12

This is in continuation of:

  1. Stability Regions for Varah's Formulas
  2. Design Notes on System for the Analysis of Order- and Stepsize Changes for Cyclic Composite Multistep Methods
  3. Tendler-like Formulas for Stiff ODEs

Below is the output of:

rm -f /tmp/v3c
stabregion4 -f Varah7 -o3 -r100 -L4:-9:22:15 | grep -Fv '[0.00000000, 0.00000000, 1]' >> /tmp/v3c
stabregion4 -f Varah8 -o3 -r100 -L4:-11:39:25 | grep -Fv '[0.00000000, 0.00000000, 1]' >> /tmp/v3c
stabregion4 -f Varah9 -o3 -r100 -L4:-20:60:50 | grep -Fv '[0.00000000, 0.00000000, 1]' >> /tmp/v3c
stabregion4 -f Varah10 -o3 -r140 -L4:-10:40:40 | grep -Fv '[0.00000000, 0.00000000, 1]' >> /tmp/v3c
stabregion4 -f Varah11 -o3 -r140 -L4:-25:40:40 | grep -Fv '[0.00000000, 0.00000000, 1]' >> /tmp/v3c
stabregion4 -f Varah12 -o3 -r140 -L4:-40:99:70 | grep -Fv '[0.00000000, 0.00000000, 1]' >> /tmp/v3c

The C source code for stabregion4 is here stabregion4.c.

You can rotate the graphics around any axis.

Varah7:

Varah8:

Varah9:

Varah10:

Varah11:

Varah12: