Search found 23 matches

by sandy12310627
3 years ago
Forum: Syntax
Topic: Too many ")'' and ')' expected
Replies: 1
Views: 1573

Too many ")'' and ')' expected

Hi! I did not find where is the mistake of my syntax about ')' I want to calculate such as below. assume r(k) = sqrt(sum(j,(DF(k-ord(j))-X(k-ord(j)))**2)/ord(k-1)), I want to set like this. r(5)=sqrt((DF(1)-X(1))**2+(DF(2)-X(2))**2+(DF(3)-X(3))**2+(DF(4)-X(4))**2/4 r(4)=sqrt((DF(1)-X(1))**2+(DF(2)-X...
by sandy12310627
3 years ago
Forum: Modeling
Topic: should I use a loop in calculate standard deviation
Replies: 1
Views: 1625

should I use a loop in calculate standard deviation

Hi! I have a problem with calculating the standard deviation in my model. I would like to assume that standard deviation is the difference between the previously estimated demand and actual demand and I have the equation shows below. image.png for example, if I want to get the standard deviation of ...
by sandy12310627
3 years ago
Forum: Modeling
Topic: Calculate after getting the optimal solution
Replies: 1
Views: 1601

Calculate after getting the optimal solution

Hi, I wonder if there is any way to do the easy calculation after I got the optimal solution. For example, I would like to use the optimal solution values (e.g., X(1), X(2), .... X(1000)) to calculate some other quantity (e.g., variance of X(1), X(2), .. X(1000)). This is just a calculation that use...
by sandy12310627
3 years ago
Forum: Modeling
Topic: Model has been proven infeasible.
Replies: 4
Views: 3149

Re: Model has been proven infeasible.

Hi, I also have a question about using time series in the modeling and ".up" of variables. set t period /1*3/ i parts /i1,i2/; parameter MC capaciy/3000/ DC capaciy/3000/ AC capaciy/500/ RC capaciy/500/ a(i) number of part i in a product /i1 1, i2 4/ c(i) Defected rate of part i /i1 0.8, i...
by sandy12310627
3 years ago
Forum: Modeling
Topic: Model has been proven infeasible.
Replies: 4
Views: 3149

Re: Model has been proven infeasible.

Hi! Thank you for helping me. I try to fix something and still get an infeasible result. Thus, I am wondering if the procedure I fixed it is correct. set t period /1*3/ i parts /i1,i2/; parameter MC capaciy/3000/ DC capaciy/3000/ AC capaciy/500/ RC capaciy/500/ a(i) number of part i in a product /i1...
by sandy12310627
3 years ago
Forum: Modeling
Topic: Model has been proven infeasible.
Replies: 4
Views: 3149

Model has been proven infeasible.

Hi, I tried to solve my model for more than 3 months... By reducing the variable, narrowing down the problem, and removing some complicated parts, the model already became a very all problem. However, the model still has been proven infeasible. I tried to find the problem of infeasible in the equati...
by sandy12310627
3 years ago
Forum: Modeling
Topic: VAR operands relational or boolean
Replies: 11
Views: 6583

Re: VAR operands relational or boolean

I know! I am trying again and again. Thank you so much!!!

Sincerely,
Sandy
by sandy12310627
3 years ago
Forum: Modeling
Topic: VAR operands relational or boolean
Replies: 11
Views: 6583

Re: VAR operands relational or boolean

Hi Michael, I very much appreciated your help a lot. I think I could understand the problem of my code; however, I do not how to fix it. I try to change the positive variable to only "variable" or change DF(1) and DF(2) to 1000 to avoid the negative solution. It still wrong. only change th...
by sandy12310627
3 years ago
Forum: Modeling
Topic: VAR operands relational or boolean
Replies: 11
Views: 6583

Re: VAR operands relational or boolean

By the way, I follow your instruction and change the code to E_DD(t)..DD(t+1)=l=DC-CU(t); E_DD2(t)..DD(t) =g= DU(t)-(DIP(t)- DIN(t))-CU(t); E_DD3(t)..DD(t) =l= 0 + sl('slack1'); E_DD4(t)..DD(t) =l= DU(t)-(DIP(t)- DIN(t))-CU(t) + sl('slack2'); However, E_DD2 and E_DD4 still have the same problem as b...
by sandy12310627
3 years ago
Forum: Modeling
Topic: VAR operands relational or boolean
Replies: 11
Views: 6583

Re: VAR operands relational or boolean

I see! thank you so much!! This is my problem. I think the attachment is not small so I ask you as a single problem. But actually I confused about this problem for about 2 months... I really need help with finding why it is not feasible. Thank you so much again for your willingness to answer my ques...