Search found 14 matches

by pelorn
4 months ago
Forum: Solvers
Topic: Initial Function Value too Large
Replies: 1
Views: 224

Initial Function Value too Large

Hi there, I get the following error message if I increase a parameter above a certain threshold: ** An initial function value is too large (larger than 1.0E+10). Scale the variables and/or equations or add bounds. Is there a way I can get GAMS to tell me which value gets too large? I can't figure ou...
by pelorn
4 months ago
Forum: Modeling
Topic: Multiple Conditions in one Equation
Replies: 4
Views: 382

Re: Multiple Conditions in one Equation

Hey,

It didnĀ“t work the way I tried it with the multiple =E= signs.

And I don't know the value, I try to optimize different paths that diverge, but they need to be equal in the first period.

Thanks
by pelorn
4 months ago
Forum: Modeling
Topic: Multiple Conditions in one Equation
Replies: 4
Views: 382

Multiple Conditions in one Equation

Hi there,

I want to set multiple variables equal to each other without having to define multiple equations for that. Is there a smooth way to do this?

I.e. something like this:

Neweq.. AI("1")=E=BI("1")=E=CI("1")=E=DI("1")

Thank you
by pelorn
4 months ago
Forum: Modeling
Topic: Double Exponent in Objective Function
Replies: 5
Views: 296

Re: Double Exponent in Objective Function

Hi Michael, Basically, I try to replicate a paper by Ackerman et al. (2013) who introduce Epstein-Zin preferences into the model. For that, I would run the model simultaneously for six different states of climate sensitivity (the code below is only for two states) from period 10 onwards, collapse th...
by pelorn
4 months ago
Forum: Modeling
Topic: Double Exponent in Objective Function
Replies: 5
Views: 296

Re: Double Exponent in Objective Function

Hey, Thanks for your replies. So real and floating numbers are not precisely the same, but how can that have such a big effect on the model? If I try to run the model with an exponent of say 1.000001 in the objective function, leaving everything unchanged (I am trying to modify one thing in the DICE...
by pelorn
4 months ago
Forum: Modeling
Topic: Sum function from t=2
Replies: 2
Views: 198

Re: Sum function from t=2

Thanks again Fred!
by pelorn
4 months ago
Forum: Modeling
Topic: Sum function from t=2
Replies: 2
Views: 198

Sum function from t=2

Hi there,

How can I use the sum function only from the second or later period (t=2) instead of all t? sum(t, periodutility(t))

Cheers
by pelorn
4 months ago
Forum: Modeling
Topic: Change Equation over time
Replies: 4
Views: 281

Re: Change Equation over time

Cool, thank you!
by pelorn
4 months ago
Forum: Modeling
Topic: Double Exponent in Objective Function
Replies: 5
Views: 296

Double Exponent in Objective Function

hi there, I want to include a function in the objective function that requires the objective to be squared first, multiplied with its probability, and then squared with the inverse again. I tried the following function to figure it out: (power((sum(t, CEMUTOTPER(t))),2))**0.5 How can I make sure tha...
by pelorn
4 months ago
Forum: Solvers
Topic: Exponent in Objective Function
Replies: 0
Views: 186

Exponent in Objective Function

Hi there,

In my model, if I leave everything the same but I include an exponent in the objective function, I get the rPower: FUNC DOMAIN: x**y, x < 0 error message.

What is the reason for that? If I run the model without that exponent modification, x is a positive number.

Many thanks