gekko

问题 I'm trying to use GEKKO to fit to a certain dataset, using the FOPDT Optimization Method to estimate k, tau and theta. I saw the example using odeint on https://apmonitor.com/pdc/index.php/Main/FirstOrderOptimization and tried to do the same thing with GEKKO, but I can't use the value of theta in the equation. I saw this question where should the delay call be placed inside a gekko code? and the docs https://apmonitor.com/wiki/index.php/Apps/TimeDelay, but in this case I wanted to estimate

问题 I am learning how to use GEKKO for kinetic parameter estimation based on laboratory batch reactor data, which essentially consists of the concentration profiles of three species A, C, and P. For the purposes of my question, I am using a model that I previously featured in a question related to parameter estimation from a single data set. My ultimate goal is to be able to use multiple experimental runs for parameter estimation, leveraging data that may be collected at different temperatures,

问题 I am learning how to use GEKKO for kinetic parameter estimation based on laboratory batch reactor data, which essentially consists of the concentration profiles of three species A, C, and P. For the purposes of my question, I am using a model that I previously featured in a question related to parameter estimation from a single data set. My ultimate goal is to be able to use multiple experimental runs for parameter estimation, leveraging data that may be collected at different temperatures,

问题 I am learning how to use GEKKO for kinetic parameter estimation based on laboratory batch reactor data, which essentially consists of the concentration profiles of three species A, C, and P. For the purposes of my question, I am using a model that I previously featured in a question related to parameter estimation from a single data set. My ultimate goal is to be able to use multiple experimental runs for parameter estimation, leveraging data that may be collected at different temperatures,

问题 I am learning how to use GEKKO for parameter estimation problems and as a first step, I am developing example problems that I have previously implemented using Scipy minimization routines. These have been done following the information available in APMonitor.com and the courses available within. The current problem is a batch reactor simulation of a methanol-to-hydrocarbons process obtained from: http://www.daetools.com/docs/tutorials-all.html#tutorial-che-opt-5 The model description can be

问题 I am using Gekko for selecting A-optimal experiments for a set of reaction kinetics. The objective function is to minimize the trace(inv(Z'Z)) where Z is a scale sensitivity matrix computed by linearizing the ODEs around its parameters. As you can see the objective function involve the inverse of Z'Z. I used the numpy (and even scipy) inverse function and I run to the following error: "No loop matching the specified signature and casting was found for ufunc inv" I really don't know what's

问题 I am using Gekko for selecting A-optimal experiments for a set of reaction kinetics. The objective function is to minimize the trace(inv(Z'Z)) where Z is a scale sensitivity matrix computed by linearizing the ODEs around its parameters. As you can see the objective function involve the inverse of Z'Z. I used the numpy (and even scipy) inverse function and I run to the following error: "No loop matching the specified signature and casting was found for ufunc inv" I really don't know what's

问题 I am trying to use GEKKO MPC to control the level of a tank while manipulating the inlet flow. I want to model the GEKKO controller as a FOPDT. I got all the parameters I need, but I want to account for the time delay using the delay function. I am not sure of the exact position of this function since it is giving me an error when I put it in the code. When I remove it (i.e. no time delay) the code works fine but I want to be more realistic and put a time delay. Here is code attached: import

问题 I'm new to gekko and APM, I'm trying to solve a problem but the solution seems to get infeasible with a new equation in a binary variable that should be viable. Here's the simplified APM model: Model Variables int_v1 = 0, >= 0 int_v2 = 0, <= 1, >= 0 v3 = 0 v4 = 0 v5 = 0 v6 = 0 End Variables Equations (0+int_v1)>=100 v3=((3.15)*(int_v1)) v4>=((int_v2)*(300)) v5=(0+((int_v1)*(3.15))) minimize v6 End Equations Connections v3 = sum_1.x[1] v4 = sum_1.y v5 = sum_2.x[1] v6 = sum_2.y End Connections

问题 I am working on a fairly large MINLP with a model size of about 270,000 variable and equations - 5,000 binaries. In using Gekko with the APOPT solver, I can solve the problem in about 868 seconds (less than 15 minutes). However, solving it on a super computer for increased memory, it takes around 27 hours to produce the results. It seems to be spending all of its time creating the model. In reading a bit about APOPT, it mentions that it works best when the Degrees of Freedom are less than 2