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4 Info Level

4.1 Introduction

Many functions of the GBNP package can produce additional output. Such output might be useful for long calculations, to see where the calculation is or to gain more information about the calculation itself.

GAP provides the tools to be able to tune the output of the functions. All of the functions of this package use the InfoClass InfoGBNP (4.2-1) and some use the InfoClass InfoGBNPTime (4.3-1). As usual with GAP when this is left at 0, the functions will hardly print additional information. It can be set to 1 or 2 with SetInfoLevel (more about this function can be found at Reference: InfoLevel). A brief explanation about each infolevel will be given in the next sections.

4.2 InfoGBNP

4.2-1 InfoGBNP

The InfoClass for this package is used in almost all functions. To change this level to 1 (some information) or 2 (more information, also information from calculation loops) use the function SetInfoLevel.

4.2-2 What will be printed at level 0

At level 0 no information is printed beyond what functions themselves command to be printed. These include functions like PrintNP (3.2-1), PrintNPList (3.2-3), PrintTraceList (3.7-2) and PrintNPListTrace (3.7-4), but it also includes the function DetermineGrowthQA (3.6-1), which only prints one or two lines and DimsQATrunc (3.8-5) which produces information about a truncated Gröbner basis.

4.2-3 What will be printed at level 1

The infolevel can be set to 1 with the following command:

SetInfoLevel(InfoGBNP,1);

At level 1 a large set of functions will produce a bit of output. Most of this information reports on the phase of the algorithm the calculations are in or some simple statistics about the input or output.

4.2-4 What will be printed at level 2

The infolevel can be set to 2 with the following command.

SetInfoLevel(InfoGBNP,2);

At level 2 a large set of functions will produce a lot of output. This mostly concerns information on loops in the calculations. Timing information will be printed as well.

4.3 InfoGBNPTime

4.3-1 InfoGBNPTime

The InfoClass for timing is used in producing information about the runtime of the algorithm in certain possibly lengthy calculations.

To change this level to 1 (Gröbner functions give information) or 2 (more information, also information from other functions, which might not always take a long time and from inside loops) use the function SetInfoLevel.

4.3-2 What will be printed at level 0

No timing information will be printed at level 0. This can be desirable for small examples or when producing test output, for use with Test.

4.3-3 What will be printed at level 1

The infolevel can be set to 1 with the following command:

SetInfoLevel(InfoGBNPTime,1);

At level one there will be time information printed by the functions from different variants of the Gröbner basis algorithm: Grobner (3.4-1), SGrobner (3.4-2), SGrobnerTrace (3.7-5), and SGrobnerTrunc (3.8-2).

4.3-4 What will be printed at level 2

The infolevel can be set to 2 with the following command:

SetInfoLevel(InfoGBNPTime,2);

At level two there will also be some information printed from a loop from within SGrobnerTrunc (3.8-2).

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