I get an error when I try to use a variable as v(i+1 , j+1).
How can I write v(i+1 , j+1) in GAMS code if I defined only v(i , j) as a variable before?
Related parts in the code are as following:
variable v(t,f);
eqn3(f,p,t) .. v(t,f)=g= r(t,p)+ (0.2*0.4*H(p)*v(t+1,f+1) + v(t+1,f)*((1-(0.4)*H(p))*(1-0.8)+(0.4)*H(p)*0.8)+ v(t+1,f-1)*((1-(0.4)*H(p))*0.8);
I get Error 198 in following parts in eqn3 : v(t+1 , f+1) , v(t+1, f ) and v(t+1 , f-1).
If you get error 198, you should actually see a little more than the number. Something like this:
198 Set used in 'ord' or lag is not ordered.
Hint: Some of the elements of the set were used before this
was initialized and the order was different from the order used
in this set. Try to initialize the set earlier.
Did you try to follow that hint?
In general, you should try to share a reproducible minimal example here when asking questions like this. That would help a lot to offer you some help here.
Edit: From the code block you added now, one can see, that the set t seems to be the problem. Though, you don't show how this got generated. Here is some explanation why this error is triggered in general and what one can do, to avoid it:
https://www.gams.com/35/docs/UG_FixingErrors.html#UG_FixingErrors_ErrorO
Related
I have the following two lines of code:
Debug.Print Forms!DocLoader!DL_RowBox!DLR_FileName.Name
Debug.Print Forms!DocLoader!DL_RowBox.Form!DLR_FileName.Name
The second one, which I have seen recommended in almost every VBA reference, including the answer being suggested from SO as I type this, follows this structure:
Debug.Print Forms![Form Name]![Subform Control Name].Form![Control Name].Name
These two lines of code should produce the same result. However, the second, recommended syntax throws error 40036, "Application-defined or object-defined error" unless I am in design view. I cannot use it at runtime, but I have never seen this limitation mentioned in any of the reference documentation or forum posts I have looked at. The first line, using only default parameters, seems to work no matter the context.
With the second line, I have tried just about every combination of bang and period I can, and I have also tried enclosing field names in brackets, but the common denominator is that as soon as I reference ".Form" the application throws an error. Even something simple like ".Form.Caption" has thrown an error. So what I would like to know is:
Are there any other correct ways of referring to a subform's form properties, since I need these as well as its controls
Why would the first line execute correctly while the second, recommended one does not seem to work?
Running the compiler appears to have fixed the issue.
I have seen a lot of questions about this but I couldn't find the correct answer for me which works.
The object which triggers the problem is like
test123.de.company.com.Database.dbo.Table
Test123.de.company.com
is the database Server.
Object name contains more than the maximum prefixes allowed
I have tried to write it like this [test123.de.company.com].Database.dbo.Table just like [test123.de.company.com].[Database].[dbo].[Table]
Can you tell me what's wrong with this?
Please try this:
["test123.de.company.com"].[Database].[dbo].[Table]
OP also encountered a new problem after implementing this solution above. OP said:
Thank you! This worked for me. To be more precise, the join is for a
view and if I save/close and then later get back to the design option
the quote marks are removed and there is [test123.de.company.com] left
over and the error returns. Is there a way to keep them fixed?
Otherwise if I change anything I always have to add the quote marks
again and again
Then with the help of DaleK that problem also was solved. DaleK:
Don't use the design option, script it as alter instead
I defined the following equation to calculate the sum of total power consumed by the system:
TotalPower.. systemPower =e= sum(J,P(J)) + sum(I,CP(I));
However, the variable systemPower gets only the result of the second sum and not both!. The declaration of P(J) is as following:
P.LO(I)=0;
P.up(I)=100;
P.l('i1')=2;
P.l('i2')=3;
Please, Can any one explain why I get the result of a single sum? How I can do to get both?. I tried also to separate them in different values but yet I get the same result.
Thank you in advance.
I though it is a good idea to share this it might help someone else. I used a variable directly instead of an equation and I put it in the following form and it worked.
systemPower.l = sum(I,P.l(I))+sum(I,CP(I));
I am working with Wolfram Mathematica 8 and have the following problem. I have an optimization problem under certain constraints and want to have an analytical (symbolical solution). I am maximizing function piA. My input is:
piA[a_, WA1_, WA0_] =
a/(1 + a)*(X - (y*WA1 + 1)^(1/y)) - 1/(1 + a) ((y*WA0 + 1)^(1/y));
Maximize[{piA[a, WA1, WA0], WA0 >= -1/y, WA1 >= -1/y}, WA0]
What I get most of the times is:
Maximize[{-((1 + WA0 y)^((1/y))/(1 + a)) + (
a (X - (1 + WA1 y)^(1/y)))/(1 + a), WA0 >= -(1/y), WA1 >= -(1/y)},a]
Basically, the command does nothing, but outputs itself. Only once I have managed to get the proper output (too long to paste here). I have tested it with simpler functions and it works. Unfortunately, I cannot understand what causes the problem. It is not a syntax problem, since it has worked like that several times. Any help would be very much appreciated.
P.S. Just checked again and my input ALWAYS generates the wrong output. The time it generated the solution was when I accidentally set parameters X and y to certain numbers.
The most likely reason is that given the function and constraints, Mathematica doesn't know how to maximize your function with respect to WA0. Note you also have a free variables X and a in there, and it might not have enough information about the domain of X and a to be able to properly form a solution to your equation.
I've had instances where I tried feeding in some equations and constraints and Mathematica simply couldn't do anything with them because they were too general. This may be the case here as well. Is there a specific problem you're trying to solve, and is there any way you could give Mathematica more context?
I don't think this is a bug at all, but it's unfortunate that sometimes Mathematica will just spit back your input when it doesn't have any rules for solving what you gave it.
The usual reason these things happens seems to be when the expressions given are too general for Mathematica to handle, or when it it's faced with a set of expressions that are ill formed.
Just as an example, I tried passing in fractions into a function I wrote that specifically looked for rational expressions, thinking it would work. It turned out that it needed to handle both Rational[a, b] and Times[a, Power[b, -1]]. It could be the case that Mathematica is not expecting a constraint to be of the form GreaterEqual[a, b].
Mathematica returns an answer if you assign the variable a some value. Maybe you could build your strategy on that? In fact it does provide an answer if you assign a value to any of the variables.
( I would need more background of the problem to go from there... )
Here is the single line from one of my functions to test if any objects in my array have a given property with a matching value
Return ((From tag In DataCache.Tags Where (tag.FldTag = strtagname) Select tag).Count = 1)
WHERE....
DataCache.Tags is an array of custom objects
strtagname = "brazil"
and brazil is definitely a tag name stored within one of the custom objects in the array.
However the function continually returns false.
Can someone confirm to me that the above should or should not work.
and if it wont work can someone tell me the best way to test if any of the objects in the array contain a property with a specific value.
I suppose in summary I am looking for the equivalent of a SQL EXISTS statement.
Many thanks in hope.
Your code is currently checking whether the count is exactly one.
The equivalent of EXISTS in LINQ is Any. You want something like:
Return DataCache.Tags.Any(Function(tag) tag.FldTag = strtagname)
(Miraculously it looks like that syntax may be about right... it looks like the docs examples...)
Many Thanks for the response.
Your code did not work. Then I realised that I was comparing to an array value so it would be case sensitive.
However glad I asked the question, as I found a better way than mine.
Many thanks again !