LIFO
Generate random numbers¶
has a number of distribution functions included, in order for you to be able to generate random numbers very efficiently. This capability might be extremely useful when you want to quickly populate a multidimensional parameter.
Say I declare a parameter 
called Traffic, over 2 
indices from the same set 
Locations with a size of 200 elements. That’s pretty much 200 * 200 = 40 000 numbers that you want to generate roughly between 0 and 200 vehicles.
Let’s create a set Locations in AIMMS, specify 2 indices l1 and l2, and define it as elementrange(1,201,1,"Location-").
Then let’s create the new parameter that we want to populate with data, over those 2 indices. To do so, just index this parameter over l1 and l2, and put uniform(0,200) in his definition. Check the data of this parameter ( CTRL + D ), and see the result:
That’s good. But if we would plot our parameter distribution we would end up with a uniform distribution.
proposes a lot of other different distributions.
Normal Distribution
\(f(x)={\tfrac {1}{\sigma {\sqrt {2\pi }}}}\;\;{\mathrm {e}}^{{-{\frac {1}{2}}\left({\frac {x-\mu }{\sigma }}\right)^{2}}}\)
Log Normal Distribution
\({\displaystyle f(x;\mu ,\sigma )={\frac {1}{x\sigma {\sqrt {2\pi }}}}\exp \left(-{\frac {(\ln x-\mu )^{2}}{2\sigma ^{2}}}\right)={\frac {1}{x}}f_{X}(\ln(x);\mu ,\sigma )}\)
See the AIMMS example project GenerateRandomNumbers.zip.
P_demand :=$
variable = 2 print 1+variable
CSVInterface.ams¶
## ams_version=1.0
Model Main_CSVInterface {
DeclarationSection Football_Ranking {
Set s_Rank {
Index: i_Rank;
}
StringParameter sp_Country {
IndexDomain: i_Rank;
}
Parameter p_Points {
IndexDomain: i_Rank;
}
}
DeclarationSection File_Information {
StringParameter sp_FileName;
StringParameter sp_SheetName;
StringParameter sp_DataSource {
InitialData: "data//";
}
StringParameter sp_OutPutFileName;
}
Section CSVLinkSetup {
StringParameter ReadWriteAttributes {
IndexDomain: dl::rwattr;
}
StringParameter DataMap {
IndexDomain: (dl::dt, dl::idn, dl::cn, dl::dn);
}
StringParameter MapName {
InitialData: "TheMapping";
}
Procedure Read_DataMapping {
Body: {
dl::DataTables += {'FootballRanking'};
!Enter the name of the CSV file without the CSV extension
DataMap(dl::dt, dl::idn, dl::cn, dl::dn) := data {
!('CSV File name, same as above', 'AIMMS Identifier', 1, 1) : "Column name in CSV file")
('FootballRanking', 's_Rank', 1, 1) : "Rank",
('FootballRanking', 'sp_Country', 2, 0) : "Country",
('FootballRanking', 'p_Points', 3, 0) : "Points"} ;
!Creating the data map between your CSV file and AIMMS Data Link
MapName := "FootballRanking";
!Give a name to your data map
dl::RemoveDataSourceMapping(MapName : MapName );
!Clearing any previously existing data maps with the same name
dl::AddDataSourceMapping(
MapName : MapName ,
DataMap : DataMap ,
ColDepend : dl::DependEmpty ,
TableAttribute : dl::TableAttributesEmpty ,
ColAttribute : dl::ColAttributeEmpty );
!Creating the new data map specified in this procedure
}
}
Procedure ReadData {
Body: {
Read_DataMapping;
!Making sure that the data map is added
ReadWriteAttributes(dl::rwattr) := {'DataProvider' : csvprovider::DataLink ,
'Separator' : "," };
!Calling the CSV provider and specifying that the separator is , in the file.
sp_DataSource := "data//";
!For the CSV provider, the Data Source is the folder in which the csv file is stored.
dl::DataRead(
DataSource : sp_DataSource ,
MapName : MapName ,
ReadAttributes : ReadWriteAttributes );
!Reading the data from the provided data source and map name information
}
}
Procedure Write_DataMapping {
Body: {
dl::DataTables += {'OutPutFile'};
!Enter the name of the CSV file without the CSV extension
DataMap(dl::dt, dl::idn, dl::cn, dl::dn) := data {
!('CSV File name, same as above', 'AIMMS Identifier', 1, 1) : "Column name in CSV file")
('OutPutFile', 's_Rank', 1, 1) : "Rank",
('OutPutFile', 'sp_Country', 2, 0) : "Country",
('OutPutFile', 'p_Points', 3, 0) : "Points"} ;
!Creating the data map between your CSV file and AIMMS Data Link
MapName := "FootballRanking";
!Give a name to your data map
dl::RemoveDataSourceMapping(MapName : MapName );
!Clearing any previously existing data maps with the same name
dl::AddDataSourceMapping(
MapName : MapName ,
DataMap : DataMap ,
ColDepend : dl::DependEmpty ,
TableAttribute : dl::TableAttributesEmpty ,
ColAttribute : dl::ColAttributeEmpty );
!Creating the new data map specified in this procedure
}
}
Procedure WriteData {
Body: {
Write_DataMapping;
!Making sure that the data map is added
ReadWriteAttributes(dl::rwattr) := {'DataProvider' : csvprovider::DataLink ,
'ContainsHeaders' : "yes" ,
'Separator' : ","};
!Calling the CSV provider
sp_DataSource := ".";
!For the CSV provider, the Data Source is the folder in which the csv file is stored.
dl::DataWrite(
DataSource : sp_DataSource ,
MapName : MapName ,
WriteAttributes : ReadWriteAttributes);
!Reading the data from the provided data source and map name information
}
}
}
Procedure SpreadSheetCSVRead {
Body: {
!specifying which file we want to interface with
sp_FileName := "data//FootballRanking.csv";
!specifying which sheet the contains the current data
sp_SheetName := "FootballRanking";
!Setting the specified sheet in the specified file as the active sheet
SpreadSheet::SetActiveSheet(
workbook : sp_FileName ,
Name : sp_SheetName );
!Reading in the set of ranks
SpreadSheet::RetrieveSet(
workbook : sp_FileName ,
Set : s_Rank ,
Range : "A2:A51" ,
Sheet : sp_SheetName , !optional if you aleady used the SetActiveSheet statement before this statemnet
Mode : 'replace' ); !optional and default 'replace' is used if nothing specified. Use 'replace' to clear set and load data and 'merge' to add new elements to set.
SpreadSheet::RetrieveParameter(
workbook : sp_FileName ,
Parameter : sp_Country(i_Rank) ,
Range : "B2:B51" ,
Sheet : sp_SheetName ,
Transposed : 0,
AutomaticallyRoundToIntegerRange : 0);
SpreadSheet::RetrieveParameter(
workbook : sp_FileName ,
Parameter : p_Points(i_Rank) ,
Range : "C2:C51" ,
Sheet : sp_SheetName ,
Transposed : 0,
AutomaticallyRoundToIntegerRange : 0);
SpreadSheet::CloseWorkbook(
workbook : sp_FileName ,
SaveBeforeClose : 1 );
}
}
Procedure SpreadSheetCSVWrite {
Body: {
!specifying which file we want to interface with
sp_OutPutFileName := "OutPut.csv";
!specifying which sheet the contains the current data
sp_SheetName := "OutPut";
SpreadSheet::CreateWorkbook(
WorkbookName : sp_OutPutFileName ,
SheetName : sp_SheetName );
!Setting the specified sheet in the specified file as the active sheet
SpreadSheet::SetActiveSheet(
workbook : sp_OutPutFileName ,
Name : sp_SheetName );
!Reading in the set of ranks
SpreadSheet::AssignSet(
workbook : sp_OutPutFileName ,
Set : s_Rank ,
Range : "A2:A51" ,
Sheet : sp_SheetName );
SpreadSheet::AssignParameter(
workbook : sp_OutPutFileName ,
Parameter : sp_Country ,
Range : "B2:B51" ,
Sheet : sp_SheetName ,
Sparse : 1,
Transposed : 0);
SpreadSheet::AssignParameter(
workbook : sp_OutPutFileName ,
Parameter : p_Points ,
Range : "C2:C51" ,
Sheet : sp_SheetName ,
Sparse : 1,
Transposed : 0);
SpreadSheet::CloseWorkbook(
workbook : sp_OutPutFileName ,
SaveBeforeClose : 1 );
}
}
Procedure MainInitialization {
Comment: "Add initialization statements here that do NOT require any library being initialized already.""
}
Procedure PostMainInitialization {
Comment: {
"Add initialization statements here that require that the libraries are already initialized properly,
or add statements that require the Data Management module to be initialized."
}
Procedure MainExecution;
Procedure PreMainTermination {
Body: {
return DataManagementExit();
}
Comment: {
"Add termination statements here that require all libraries to be still alive.
Return 1 if you allow the termination sequence to continue.
Return 0 if you want to cancel the termination sequence."
}
Procedure MainTermination {
Body: {
return 1;
}
Comment: {
"Add termination statements here that do not require all libraries to be still alive.
Return 1 to allow the termination sequence to continue.
Return 0 if you want to cancel the termination sequence.
It is recommended to only use the procedure PreMainTermination to cancel the termination sequence and let this procedure always return 1."
}
}
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Last Updated: May, 2019