Re: [AMPL 12375] How to define a set with two parameters where value is binary

[Victor Zverovich]

From your descriptions, it looks like jobs and tools should be sets, not parameters, and matrix will be a parameter indexed over these two sets:

  set jobs;

  set tools;

  param use{jobs, tools} binary;

  data;

  set jobs := j1 j2 j3 j4;

  set tools := t1 t2 t3;

  param use:

       t1   t2    t3 :=

    j1  1    1     0

    j2  0    1    1

    j3  1    0    1

    j4  0    0    1;

HTH,

Victor

On Thu, Jul 28, 2016 at 9:35 AM biz <issab...@gmail.com> wrote:

Hello everyone ! I am new to AMPL and this is my first post, any suggestions or help is much appreciated

I have two parameters let's say job and tools and this matrix 

     t1   t2    t3

j1  1    1     0

j2   0    1    1

j3   1    0    1

j4   0    0    1

so here it means job1 can use either tool1 or tool2 to be processed , job2 can use either tool2 or tool3 .. etc , so my question is how to write this in AMPL 

and create a set let’s say set A; for this two parameters to be used in the following constraint 

{h in 1..H} : sum {m in 1..M,j in A} p[j,m] * X[j,h,m] <= TL[t] * TC[t];

where h is the number of periods, m number of modes ( different processing time and cost for different modes), 

      j is the number of jobs, and t is the number of tools , 

      X is binary decision variable. 

      TL and TC : capacity of tools for only tools in set A 

Any help is much appreciated

Thank you 

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[biz]

Thank you Victor for your reply , it worked perfectly . 

If you don't mind, I have 2 small questions regarding the same problem , 

1.  I have created a random  binary matrix using this : param use{jobs, tools} = floor(Uniform(0,2)), 

    however , I want to have at least a '1' in each row in case all the values are , for ex : 

After generating the random binary matrix,  I got this result but I want to change the last row to have at least '1' in any position

        t1   t2    t3   t4 :=

    j1  1    1     0   1

    j2  0    1    1    0

    j3  1    0    1    0

    j4  0    0    0    0;

2. How could i transpose this matrix to another param lets say:  param use2{tools, jobs} to have the same value as above. 

Thank you in advance and appreciate your help. 

[Victor Zverovich]

1. You can use the let statement to assign values to parameter ``use`` instead of doing it in the initializer:

  param use{jobs, tools};

  let{j in jobs, t in tools} use[j, t] := floor(Uniform(0,2));

  let use['j4', 't1'] := 1;

2. You can define a transposed version of ``use`` as follows:

  param use2{t in tools, j in jobs} = use[j, t];

HTH,

Victor