Access to Integer Control Variables

EKKIGET - Request Current Values of Integer Control Variables
EKKISET - Set Integer Control Variables
Table of Integer Control Variables
Appendix C. Control Variables
Index to Modules
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EKKIGET - Request Current Values of Integer Control Variables

This subroutine requests current values of the integer (fullword) control variables.

Syntax

C	ekkiget(&rtcod,dspace,iarray,num);
FORTRAN	CALL EKKIGET(rtcod,dspace,iarray,num)

On Entry

dspace: is the user-provided work area.
num: is the number of control variables to be retrieved.

On Return

rtcod: is the return code for the subroutine, where:
dspace: is the user-provided work area.
iarray: is an array of integer control variables, where the nth entry of iarray is the nth integer control variable.

Refer to Table 14 for a list of integer control variables.

Notes

The number of control variables returned is the minimum of the number requested, num, and the number available.
Some integer control variables are bit masks. A bit mask is a bit string that is used to specify one or more options by adding their values together. For example, for integer control variable 31, Imodelmask, if you want to specify the common block and the names of the rows and columns, you add their values together (1+4), and set Imodelmask to the sum, 5.

In this book, the symbol is used to indicate that a bit is set. For example, 1, 4 Imodelmask indicates that the 1 and 4 bits of the integer control variable Imodelmask are set. Imodelmask would then have a value of 5 as described above.

Examples

Refer to the following sample programs for examples of using EKKIGET:

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EKKISET - Set Integer Control Variables

This subroutine sets the values of integer (fullword) control variables. EKKIGET must be called before calling EKKISET.

See "Controlling OSL" for information on how control variables work and how to set them.

Syntax

FORTRAN	CALL EKKISET(rtcod,dspace,iarray,num)
C	ekkiset(&rtcod,dspace,iarray,num);

On Entry

dspace: is the user-provided work area.
iarray: is an array of integer control variables, where the nth entry of iarray is the nth control variable.
num: is the number of control variables to be set.

On Return

rtcod: is the return code for the subroutine, where:
dspace: is the user-provided work area.

Notes

Refer to Appendix C. "Control Variables" and Table 15 in EKKIGET for a complete description of the integer control variables.
All valid control variable set requests are carried out even if an earlier one is rejected as invalid.
Some integer control variables are bit masks. A bit mask is a bit string that is used to specify one or more options by adding their values together. For example, for integer control variable 31, Imodelmask, if you want to specify the common block and the names of the rows and columns, you add their values together (1+4), and set Imodelmask to the sum, 5.

In this book, the symbol is used to indicate that a bit is set. For example, 1, 4, Imodelmask indicates that the 1 and 4 bits of the integer control variable Imodelmask are set. Imodelmask would then have a value of 5 as described above.

If you want to set any integer control variables that are related to sizes of arrays before calling EKKMPS, EKKLMDL, EKKNMDL, or EKKSMDL, you must call EKKDSCM before EKKIGET and EKKISET. These variables are Imaxrows, Imaxcols, Imaxints, Imaxsets, and Imaxintinfo.
When you use EKKIGET before calling EKKMPS, EKKLMDL, or EKKSMDL, if Imaxrows and Imaxcols are positive, they have their usual meanings; if they are negative, they act as increments (that is, Imaxrows will be set to Inumrows + ( -Imaxrows)). This is useful if you want to have spare rows.

This does not apply when you use EKKIGET before calling EKKNMDL.

Examples

Refer to the following sample programs for examples of using EKKISET:

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Table 14. Integer Control Variables

iarray Index Variable Name Lower Limit Upper Limit Default Value Explanation

1 Ilogfreq 1 maxint^** 999,999 The log frequency.

2 Iprintunit 0 99 6 The unit number for printed output.

3 Imaxfactor 0 999 100 + (Inumrows) / 100 The maximum number of iterations before a refactorization (invert) of the basis must be performed.

4^* Iiternum 0 maxint 0 The current number of iterations OSL has performed in a solve subroutine.

5 Imaxiter 0 maxint 9,999,999 The maximum number of iterations OSL will perform.

6 Iloglevel 0 63 15 The simplex log detail bit mask.

7 Ioneobj 0 1 1 One objective function (type-N row) flag for MPS files.

8^* Iqparnumiter 0 maxint 0 The number of the current EKKQPAR parametric adjustment.

9 Imaxrows -maxint^§ maxint^§ 0 The maximum number of rows allowed in the matrix.

10 Imaxcols -maxint^§ maxint^§ 0 The maximum number of columns allowed in the matrix.

11 Inumchar 1 31 8 The number of characters in row names, column names, and names of problems in MPS data sets.

12 Istopmask 0 3 0 The stopping condition bit mask.

13 Imaxiterb 0 maxint 100 The maximum number of iterations of the interior-point barrier algorithm.

14 Iadjactype 0 1 1 Contols formation of the adjacency matrix A A ^T

15 Iformntype 0 1 0 The formation of the normal matrix.

16 Idensecol 10 maxint 99,999 The dense column threshold.

17 Idevexmode -3 3 1 The type of Devex pricing to be used.

18 Inullcheck -maxint maxint 0 The null space checking switch.

19 Idroprowct 1 30 1 The constraint dropping threshold.

20 Iiterufreq 0 maxint 1 The frequency with which EKKITRU is called.

21 Ipossbasis 0 maxint 65 The potential basis flag.

22 Imaxprojns 1 10 3 The maximum null space projections.

23^* Inumels 0 maxint n/a The number of elements in the last created matrix block.

24 Inumblocks 0 maxint 0 The number of matrix blocks.

25 Imsgpos 0 1 0 The position of the message number on the output line.

26 Ipagelines 10 maxint 55 The number of lines on the output page.

27 Inumrows 0 Imaxrows^§ 0 The number of rows in the matrix.

28 Inumcols 0 Imaxcols^§ 0 The number of structural variables in the matrix.

29^* Inumpinf 0 Inumrows n/a The current number of primal infeasibilities.

30^* Inumdinf 0 Inumcols n/a The current number of dual infeasibilities.

31 Imodelmask 0 8191 0 The bit mask that determines which parts of the matrix are written or read by EKKPTMD or EKKGTMD.

32 Iprtinfomask 0 1023 31 The solution information bit mask for EKKPRTS.

33 Isolmask 0 16 0 The print matrix bit mask for EKKPRTS.

34 Iextrablk 1 maxint 1,000 The number of elements in each spare block.

35 Iqparmaxiter 0 maxint 9,999,999 The maximum number of parametric adjustments that will be performed by EKKQPAR.

36 Ilinelen 60 150 80 The length of the output line.

37^* Inumnodes 0 maxint 0 The maximum node number created so far.

38 Iintmask 0 63 1 The EKKMSLV log detail bit mask.

39 Ifastits -maxint maxint 0 The fast iteration switch.

40 Imaxnodes 0 maxint 9,999,999 The maximum number of nodes to evaluate.

41 Imaxsols 0 maxint 9,999,999 The maximum number of feasible integer solutions to find.

42^* Inumsols 0 Imaxsols 0 The number of integer solutions found so far.

43^* Inumints 0 Imaxints 0 The number of individual integer variables.

44^* Inumsets 0 maxint 0 The number of sets.

45^* Inumunsat 0 maxint 0 The number of integer variables at fractional values.

46 Ivector 0 1 1 IBM Vector Facility flag.

47^* Iprobstat -1 6 -1 The problem status.

48 Imajorits 0 999 30 The maximum number of decomposition iterations.

49 Iprintsens 0 1023 0 The sensitivity information printing bit mask.

50 Imaxints -maxint maxint 0 The maximum number of integer variables.

51 Imaxsets -maxint maxint 0 The maximum number of sets.

52 Istrategy 0 3 1 The bit mask that selects various steps of the MIP algorithm.

53 Imaxintinfo -maxint maxint 0 The maximum amount of integer information.

54 Ithreshold 0 maxint 1 Number of integer variables that must be fixed for supernode processing to continue.

55 Iheurpass 0 maxint 1 The number of heuristic passes to be made by EKKMPRE.

56 Isupertol 0 maxint Number of 0-1 variables The number of branches allowed inside a supernode before supernode processing ends.

57 Iroword -1 1 1 The row ordering method indicator.

58 Iordunit -1 99 -1 The row ordering read and write logical unit.

59 Imiplength 0 maxint 0 The amount of extra information that is saved and restored by the user exit subroutine EKKNODU.

60^* Iiterbnum 0 maxint 0 The current number of iterations EKKBSLV has performed.

61 Ipricetype 0 1 0 The type of pricing for EKKNSLV.

63^* Iprobstat2 -1 3 -1 A secondary problem status variable.

64^* Ismdltypemask 0 7 0 The bit mask that indicates the type of model read in by EKKSMDL.

69^* Inumelq 0 maxint 0 The number of elements or columns in the quadratic matrix.

70 Iordthrsh 0 maxint 0 The ordering threshold.

71 Ilpdcflag 0 maxint 0 The number of blocks into which ekklpdc will attempt to decompose the constraint matrix.

^*Not settable.
^**maxint is the maximum integer allowed on your platform.
^§Bounded by the size of dspace or file size.
Note: See Appendix C. "Control Variables" for a list, and explanation, of all the control variables.

iarray Index	Variable Name	Lower Limit	Upper Limit	Default Value	Explanation
1	Ilogfreq	1	maxint^**	999,999	The log frequency.
2	Iprintunit	0	99	6	The unit number for printed output.
3	Imaxfactor	0	999	100 + (Inumrows) / 100	The maximum number of iterations before a refactorization (invert) of the basis must be performed.
4^*	Iiternum	0	maxint	0	The current number of iterations OSL has performed in a solve subroutine.
5	Imaxiter	0	maxint	9,999,999	The maximum number of iterations OSL will perform.
6	Iloglevel	0	63	15	The simplex log detail bit mask.
7	Ioneobj	0	1	1	One objective function (type-N row) flag for MPS files.
8^*	Iqparnumiter	0	maxint	0	The number of the current EKKQPAR parametric adjustment.
9	Imaxrows	-maxint^§	maxint^§	0	The maximum number of rows allowed in the matrix.
10	Imaxcols	-maxint^§	maxint^§	0	The maximum number of columns allowed in the matrix.
11	Inumchar	1	31	8	The number of characters in row names, column names, and names of problems in MPS data sets.
12	Istopmask	0	3	0	The stopping condition bit mask.
13	Imaxiterb	0	maxint	100	The maximum number of iterations of the interior-point barrier algorithm.
14	Iadjactype	0	1	1	Contols formation of the adjacency matrix A A ^T
15	Iformntype	0	1	0	The formation of the normal matrix.
16	Idensecol	10	maxint	99,999	The dense column threshold.
17	Idevexmode	-3	3	1	The type of Devex pricing to be used.
18	Inullcheck	-maxint	maxint	0	The null space checking switch.
19	Idroprowct	1	30	1	The constraint dropping threshold.
20	Iiterufreq	0	maxint	1	The frequency with which EKKITRU is called.
21	Ipossbasis	0	maxint	65	The potential basis flag.
22	Imaxprojns	1	10	3	The maximum null space projections.
23^*	Inumels	0	maxint	n/a	The number of elements in the last created matrix block.
24	Inumblocks	0	maxint	0	The number of matrix blocks.
25	Imsgpos	0	1	0	The position of the message number on the output line.
26	Ipagelines	10	maxint	55	The number of lines on the output page.
27	Inumrows	0	Imaxrows^§	0	The number of rows in the matrix.
28	Inumcols	0	Imaxcols^§	0	The number of structural variables in the matrix.
29^*	Inumpinf	0	Inumrows	n/a	The current number of primal infeasibilities.
30^*	Inumdinf	0	Inumcols	n/a	The current number of dual infeasibilities.
31	Imodelmask	0	8191	0	The bit mask that determines which parts of the matrix are written or read by EKKPTMD or EKKGTMD.
32	Iprtinfomask	0	1023	31	The solution information bit mask for EKKPRTS.
33	Isolmask	0	16	0	The print matrix bit mask for EKKPRTS.
34	Iextrablk	1	maxint	1,000	The number of elements in each spare block.
35	Iqparmaxiter	0	maxint	9,999,999	The maximum number of parametric adjustments that will be performed by EKKQPAR.
36	Ilinelen	60	150	80	The length of the output line.
37^*	Inumnodes	0	maxint	0	The maximum node number created so far.
38	Iintmask	0	63	1	The EKKMSLV log detail bit mask.
39	Ifastits	-maxint	maxint	0	The fast iteration switch.
40	Imaxnodes	0	maxint	9,999,999	The maximum number of nodes to evaluate.
41	Imaxsols	0	maxint	9,999,999	The maximum number of feasible integer solutions to find.
42^*	Inumsols	0	Imaxsols	0	The number of integer solutions found so far.
43^*	Inumints	0	Imaxints	0	The number of individual integer variables.
44^*	Inumsets	0	maxint	0	The number of sets.
45^*	Inumunsat	0	maxint	0	The number of integer variables at fractional values.
46	Ivector	0	1	1	IBM Vector Facility flag.
47^*	Iprobstat	-1	6	-1	The problem status.
48	Imajorits	0	999	30	The maximum number of decomposition iterations.
49	Iprintsens	0	1023	0	The sensitivity information printing bit mask.
50	Imaxints	-maxint	maxint	0	The maximum number of integer variables.
51	Imaxsets	-maxint	maxint	0	The maximum number of sets.
52	Istrategy	0	3	1	The bit mask that selects various steps of the MIP algorithm.
53	Imaxintinfo	-maxint	maxint	0	The maximum amount of integer information.
54	Ithreshold	0	maxint	1	Number of integer variables that must be fixed for supernode processing to continue.
55	Iheurpass	0	maxint	1	The number of heuristic passes to be made by EKKMPRE.
56	Isupertol	0	maxint	Number of 0-1 variables	The number of branches allowed inside a supernode before supernode processing ends.
57	Iroword	-1	1	1	The row ordering method indicator.
58	Iordunit	-1	99	-1	The row ordering read and write logical unit.
59	Imiplength	0	maxint	0	The amount of extra information that is saved and restored by the user exit subroutine EKKNODU.
60^*	Iiterbnum	0	maxint	0	The current number of iterations EKKBSLV has performed.
61	Ipricetype	0	1	0	The type of pricing for EKKNSLV.
63^*	Iprobstat2	-1	3	-1	A secondary problem status variable.
64^*	Ismdltypemask	0	7	0	The bit mask that indicates the type of model read in by EKKSMDL.
69^*	Inumelq	0	maxint	0	The number of elements or columns in the quadratic matrix.
70	Iordthrsh	0	maxint	0	The ordering threshold.
71	Ilpdcflag	0	maxint	0	The number of blocks into which ekklpdc will attempt to decompose the constraint matrix.
^Not settable. ^*maxint is the maximum integer allowed on your platform. ^§Bounded by the size of dspace or file size. Note: See Appendix C. "Control Variables" for a list, and explanation, of all the control variables.

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