What is the purpose for the default type values _i, _f, _s and _o?

answered 2012-01-22 18:51:33 -0500

JervisW
1298 ●20 ●34 ●55

• _i - default integer
• _f - default floating point
• _s - default character / string
• _o - default filename

And here is an explanation as applied to your example:

psspy.solution_parameters_3(
    [_i,200,_i],
    [_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f])

The user wanted to change the second integer solution parameter, but not the first or third, and didn't want to change any of the floating point solution parameters.

So what are the first and third integer solution parameters? Well from the docs:

INTGAR(1)  - ITMX, Gauss-Seidel maximum number of iterations.
INTGAR(2)  - ITMXN, Newton-Rapheson maximum number of iterations.
INTGAR(3)  - ITMXTY, TYSL maximum number of iterations.

In your example you wanted to increase the Newton Rapheson iteration limit to 200 but leave the Gauss-Seidel and TYSL iteration limits alone. But you don't know ahead of time what the Gauss-Seidel or TYSL values already where, so you can't type them in with the 200:

psspy.solution_parameters_3(
    [2?,200,10?])

so instead we use the default value which means - Don't change this value, leave it the way it was.

Here is another way to update one value without changing the others:

# increase Newton-Rapheson iteration limit.
psspy.solution_parameters_3(intgar2=200)

we specify the same name as in the documentation INTGAR(2) as lowercase and without the brackets intgar2.