topic Re: Data handling and constraint setting for bin packing optmodel example in Mathematical Optimization, Discrete-Event Simulation, and OR

Data handling and constraint setting for bin packing optmodel example

Hendrik — Thu, 12 Jul 2018 21:53:00 GMT

Hi,

I am setting up a bin packing model based on the SAS example (http://support.sas.com/documentation/cdl/en/ormpug/67517/HTML/default/viewer.htm#ormpug_decomp_examples06.htm)

The data definition step looks as follows:

data dvr;

input opponent $ size;

datalines;

Clemson 1.36

Clemson2 1.97

Duke 2.76

Duke2 2.52

FSU 2.56

FSU2 2.34

GT 1.49

[...]

;

I am new to SAS and don't really know how to access the data. In my application, I have a third value (rating) for each data row as follows:

data dvr;

input opponent $ size $ rating;

datalines;

Clemson 1.36 1

Clemson2 1.97 2

Duke 2.76 3

Duke2 2.52 3

FSU 2.56 2

FSU2 2.34 1

GT 1.49 2

[...]

I thought that I can call these values like using an array but it does not work.

I would like to set up a constraint that compares the third value to another value and sets up a constraint.

If anybody could help me and give a hint on how I can access or loop though these values, it would be amazing!

Re: Data handling and constraint setting for bin packing optmodel example

RobPratt — Fri, 13 Jul 2018 01:52:48 GMT

The "size" column is numeric, so omit the $ in the DATA step INPUT statement:

input opponent $ size rating;

The following PROC OPTMODEL statements show how to modify the documentation example to read the additional "rating" column:

   set <str> PRODUCTS;
   num size {PRODUCTS};
   num rating {PRODUCTS};
   read data dvr into PRODUCTS=[opponent] size rating;

Re: Data handling and constraint setting for bin packing optmodel example

Hendrik — Mon, 16 Jul 2018 17:44:43 GMT

Thank you for your answer Rob! Based on this, how do I access the parameter?
For example, if I would like to print the rating of FSU, is there a way to say 'put PRODUCTS[5,3]?

Re: Data handling and constraint setting for bin packing optmodel example

RobPratt — Mon, 16 Jul 2018 18:08:26 GMT

put rating['FSU'];

Re: Data handling and constraint setting for bin packing optmodel example

Hendrik — Mon, 16 Jul 2018 18:16:05 GMT

Thank you for your quick reply Rob!

This works fine and I noticed, I should have asked the question differently... Is it possible to iterate through these parameters (in array shape)?

For example:

for all i in rows:

for all j in columns:

put arrayelement[i,j]

Thank you in advance, Hendrik

Re: Data handling and constraint setting for bin packing optmodel example

RobPratt — Mon, 16 Jul 2018 18:40:15 GMT

Yes, you can explicitly loop through the index sets of these one-dimensional arrays:

for {i in OPPONENTS} put size[i] rating[i];

Or implicitly loop:

put size[*] rating[*];

Or include an equals sign to also display the names:

for {i in OPPONENTS} put size[i]= rating[i]=;

put size[*]= rating[*]=;

Or just print:

print size rating;

Re: Data handling and constraint setting for bin packing optmodel example

Hendrik — Tue, 17 Jul 2018 18:42:15 GMT

Thank you Rob!