# AUTO_SOLUTION_STRATEGY

Automatically creates a solution strategy by issuing all the other commands in this chapter.

AcuTrace Command

## Syntax

AUTO_SOLUTION_STRATEGY {parameters}

## Qualifier

This command has no qualifier.

## Parameters

max_time (real) >=0 [=0]
Final time of the particle trace. The trace of an individual particle will terminate when its trace time reaches this value. The trace may terminate earlier due to other criteria. If zero, this option is ignored.
max_segments (integer) >=0 [= 100000]
Maximum number of segments in the trace of any one particle. The trace of an individual particle will terminate when the number of segments in its trace reaches this value. The trace may terminate earlier due to other criteria. If zero, this option is ignored.

## Description

The goal of the AUTO_SOLUTION_STRATEGY command is to completely automate the specification of all the solution strategy commands based on the physical specification of the problem. This is not entirely possible currently but for most problems it is. AUTO_SOLUTION_STRATEGY is a functional command, hence it is processed immediately upon being read from the input file. As such its position in the input file may be very important. When AUTO_SOLUTION_STRATEGY is issued, the parameters of the previously-given EQUATION command are used to determine what equations are being solved. Then the appropriate TIME_SEQUENCE and STAGGER commands are issued. These commands are also saved in a file called problem.pa.inc, where problem is specified by theproblem parameter in the FLOW_FIELD command. The parameters from these commands may be overwritten afterwards by manually issuing the commands. On the next run, problem.pa.inc may be included (modified or not) instead of AUTO_SOLUTION_STRATEGY.

For example, the simplest form of this command for particle tracing without stretch is
EQUATION {
particle = massless
}
AUTO_SOLUTION_STRATEGY {
}
For particle tracing with stretch the command is
EQUATION {
particle = massless
stretch  = standard
}
AUTO_SOLUTION_STRATEGY {
}
For particle tracing with stretch and user equations ener and temp the command is
EQUATION {
particle = massless
stretch  = standard
user_equations = {ener, temp}
}
AUTO_SOLUTION_STRATEGY {
}

One can discover the stagger names used in the staggers parameter of the TIME_SEQUENCE command by examining the problem.pa.inc file.