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Stability toolbox

Commands of the stability_toolbox chapter of the database, 5 entries. The status words are defined once, on the compatibility matrix, which says what each rests on and what the script builder does with it. Read it before this page: broken and removed are refusals, so a row here can be telling you the emitter will not write that command for that version.

COMPUTE_STABILITY_COEFFICIENTS

Phase analysis, layout bare. Manual: SRC-003 pp.371-372.

Runs the whole set. EXPECT IT TO BE THE EXPENSIVE COMMAND OF THE CHAPTER, and read that as an expectation rather than as a page fact, because no edition states the cost. A derivative is a difference between states, and the settings command above exposes a per-run clearing switch and a rate increment, which together say the toolbox re-solves; how many times it does so for a given set of coefficients is not documented and has not been measured here.

Version Status Evidence
25.000 documented SRC-749 p.332, same grammar as 26.120
25.100 documented SRC-748 p.344, same grammar as 26.120
26.000 documented SRC-747 p.343, same grammar as 26.120
26.100 documented SRC-741 pp.366-367, same grammar as 26.120
26.101 documented SRC-725 pp.370-371, same grammar as 26.120
26.120 documented SRC-003 pp.371-372
26.121 documented SRC-740 pp.374-375, same grammar as 26.120
26.123 documented SRC-751 p.378, unchanged from SRC-750 p.378
26.124 documented SRC-752 p.378, the SRC-751 file, carried from 26.123; not run on 26.124

STABILITY_TOOLBOX_DELETE_ALL

Phase analysis, layout bare. Manual: SRC-003 p.371.

Deletes every user-defined coefficient. There is no command deleting one, so correcting a single definition means rebuilding the set.

Version Status Evidence
25.000 documented SRC-749 p.331, same grammar as 26.120
25.100 documented SRC-748 p.344, same grammar as 26.120
26.000 documented SRC-747 p.343, same grammar as 26.120
26.100 documented SRC-741 p.366, same grammar as 26.120
26.101 documented SRC-725 p.370, same grammar as 26.120
26.120 documented SRC-003 p.371
26.121 documented SRC-740 p.374, same grammar as 26.120
26.123 documented SRC-751 p.378, unchanged from SRC-750 p.378
26.124 documented SRC-752 p.378, the SRC-751 file, carried from 26.123; not run on 26.124

STABILITY_TOOLBOX_EXPORT

Phase analysis, layout inline. Manual: SRC-003 p.372.

Writes the computed coefficients to a file, the path on the next line. It is the only command in the chapter that produces an artifact a script can read back; whether the solver also prints the coefficients to its log is not documented and has not been observed here.

Argument Specification
file path
Version Status Evidence
25.000 documented SRC-749 p.332, same grammar as 26.120
25.100 documented SRC-748 p.345, same grammar as 26.120
26.000 documented SRC-747 p.344, same grammar as 26.120
26.100 documented SRC-741 p.367, same grammar as 26.120
26.101 documented SRC-725 p.371, same grammar as 26.120
26.120 documented SRC-003 p.372
26.121 documented SRC-740 p.375, same grammar as 26.120
26.123 documented SRC-751 p.379, unchanged from SRC-750 p.379
26.124 documented SRC-752 p.379, the SRC-751 file, carried from 26.123; not run on 26.124

STABILITY_TOOLBOX_NEW_COEFFICIENT

Phase analysis, layout keyword_block. Manual: SRC-003 p.371.

Defines one derivative: a numerator variable over a denominator variable, scaled by a constant, computed on a named set of boundaries in a named frame. THE KEYWORD ORDER HERE IS THE SAMPLES' AND NOT THE TABLE'S, AND IT DOES NOT MATTER. The parameter table lists NAME, NUMERATOR, FRAME, UNITS, DENOMINATOR, CONSTANT, BOUNDARIES; both printed samples write DENOMINATOR before FRAME and UNITS. The samples are followed here because two agreeing runnable lines beat a table's layout. That choice was made while it was unknown whether the solver reads keyword order at all, and RPT-019 then measured it: a keyword block is matched by KEYWORD, and a fully reversed block leaves the same state. So the disagreement on this page has no consequence, and no future chapter needs to weigh a table's order against a sample's. BOUNDARIES CARRIES THE COUNT AND -1 MEANS ALL, in which case no index line follows. Both forms are printed as samples, which is why the index list is optional here: the second sample passes 3 and then a line of three indices, the first passes -1 and nothing. CONSTANT is the caller's own scale factor, typically carrying the reference length and velocity that non-dimensionalise a rate derivative. No edition states what it should be for a given derivative, so nothing here can check it, and a wrong constant produces a plausible number rather than an error.

Argument Specification
name str
numerator enum in
denominator enum in
frame int
units enum in
constant float
boundaries int
boundary_indices int_list (optional)
Version Status Evidence
25.000 documented SRC-749 p.331, same grammar as 26.120
25.100 documented SRC-748 p.344, same grammar as 26.120
26.000 documented SRC-747 p.343, same grammar as 26.120
26.100 documented SRC-741 p.366, same grammar as 26.120
26.101 documented SRC-725 p.370, same grammar as 26.120
26.120 documented SRC-003 p.371
26.121 documented SRC-740 p.374, same grammar as 26.120
26.123 documented SRC-751 p.378, unchanged from SRC-750 p.378
26.124 documented SRC-752 p.378, the SRC-751 file, carried from 26.123; not run on 26.124

STABILITY_TOOLBOX_SETTINGS

Phase analysis, layout inline. Manual: SRC-003 p.371.

Settings shared by every coefficient the toolbox computes. TWO UNIT DECISIONS SIT IN ONE COMMAND AND THEY ARE NOT THE SAME DECISION. UNITS states whether the derivatives are reported per radian or per degree, and it is a property of the OUTPUT. ANGULAR_RATE_INCREMENT is an INPUT and the manual gives it in radians per second regardless, so setting PER_DEGREE does not change the unit this argument is read in. A reader who assumes it does is off by a factor of about 57 in the perturbation that every dynamic derivative is differenced from. CLEAR_SOLVER_PER_RUN decides whether each perturbed run starts from a cleared solution or from the previous one, which is what the parameter row states. The page says nothing about what the choice costs or changes; treating it as a numerical decision rather than a convenience is this database's advice and not a measurement.

Argument Specification
rotation_frame int
units enum in
clear_solver_per_run enum in
angular_rate_increment float [rad/s]
Version Status Evidence
25.000 documented SRC-749 p.331, same grammar as 26.120
25.100 documented SRC-748 p.344, same grammar as 26.120
26.000 documented SRC-747 p.343, same grammar as 26.120
26.100 documented SRC-741 p.366, same grammar as 26.120
26.101 documented SRC-725 p.370, same grammar as 26.120
26.120 documented SRC-003 p.371
26.121 documented SRC-740 p.374, same grammar as 26.120
26.123 documented SRC-751 p.378, unchanged from SRC-750 p.378
26.124 documented SRC-752 p.378, the SRC-751 file, carried from 26.123; not run on 26.124