如何查看 Gekko 变量/参数以进行调试？

Question

I have a fitting task where I am using GEKKO.

There are a lot of variables, arrays of variables, some variables that must contain arrays, and so on.

I didn't have success with the fitting, so I need to do step-by-step verification of all parameters that I am providing for GEKKO and all the calculated intermediate values.

Is there a way to print out the values of each variable for debugging purposes? Or to view the values of the variables in line-by-line execution?

for example, I have an array that is saved like a variable ro :

phi = model.Intermediate( c * ro) # phase shift 

where c is some constant defined somewhere above in the model definition.

How can I view the values inside phi that will be used in the next steps?

I need to view/save all the values of all variables/constants/intermediates used during the model creation - before a try to solve. Is it possible?

Answer 1

Turn up the DIAGLEVEL to 2 or higher to produce diagnostic files in the run directory m.path .

from gekko import GEKKO
m = GEKKO(remote=False)
c = 2
x = m.Param(3,name='x')
ro = m.Var(value=4,lb=0,ub=10,name='ro')
y = m.Var()
phi = m.Intermediate(c*ro,name='phi')
m.Equation(y==phi**2+x)
m.Maximize(y)
m.options.SOLVER = 1
m.options.DIAGLEVEL=2
m.open_folder()
m.solve()

Here is a summary of the diagnostic files that are produced:

Variables, Equations, Jacobian, Lagrange Multipliers, Objective

• apm_eqn.txt
• apm_jac.txt
• apm_jac_fv.txt
• apm_lam.txt
• apm_lbt.txt
• apm_obj.txt
• apm_obj_grad.txt
• apm_var.txt

Solver Output and Options

• APOPT.out
• apopt_current_options.opt

Model File

• gk_model0.apm

Data File

• gk_model0.csv

Options Files

• gk_model0.dbs
• options.json

Specification File for FV, MV, SV, CV

• gk_model0.info

Inputs to the Model

• dbs_read.rpt
• input_defaults.dbs
• input_gk_model0.dbs
• input_measurements.dbs
• input_overrides.dbs
• measurements.dbs

Results

• rto.t0
• results.csv
• results.json
• gk_model0_r_2022y12m04d08h12m28.509s.t0

Initialization Steps Before Solve

• rto_1.t0
• rto_2.t0
• rto_3.t0
• rto_3_eqn.txt
• rto_3_eqn_var.txt
• rto_3_var.t0

Reports After Solve

• rto_4.t0
• rto_4_eqn.txt
• rto_4_eqn_var.txt
• rto_4_var.t0

The files of interest for you are likely the rto* initialization files. The name changes based on the IMODE that you run. It is mpu* for your application for a Model Parameter Update with IMODE=2 .