Goto Chapter: Top 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A B C Bib Ind

### 13 External packages

The use of the packages NormalizInterface [GHS14] (an interface to Normalize [BIRC14]; or in its absence 4ti2Interface[Gut], and interface to 4ti2[tt]), SingularInterface (an interface to Singular [DGPS12]; or in its absence Singular [CdG12]); or in its absence GradedModules [BGJ+14] is highly recommended for many of the functions presented in this chapter. However, whenever possible a method not depending on these packages is also provided (though slower). The package tests if the user has downloaded any of the above packages, and if so puts NumSgpsCanUsePackage to true, where Package is any of the above.

#### 13.1 Using external packages

As mentioned above some methods are specifically implemented to take advantage of several external packages. The following functions can be used in case these packages have not been loaded prior to numericalsgps.

##### 13.1-1 NumSgpsUse4ti2
 ‣ NumSgpsUse4ti2( ) ( function )

Tries to load the package 4ti2Interface. If the package is available, then it also loads methods implemented using functions in this package.

##### 13.1-2 NumSgpsUse4ti2gap
 ‣ NumSgpsUse4ti2gap( ) ( function )

Tries to load the package 4ti2gap. If the package is available, then it also loads methods implemented using functions in this package.

##### 13.1-3 NumSgpsUseNormalize
 ‣ NumSgpsUseNormalize( ) ( function )

Tries to load the package NormalizInterface. If the package is available, then it also loads methods implemented using functions in this package.

##### 13.1-4 NumSgpsUseSingular
 ‣ NumSgpsUseSingular( ) ( function )

Tries to load the package singular. If the package is available, then it also loads methods implemented using functions in this package.

To prevent incompatibilities, the package will not load if SingularInterface has been already loaded.

##### 13.1-5 NumSgpsUseSingularInterface
 ‣ NumSgpsUseSingularInterface( ) ( function )

Tries to load the package SingularInterface. If the package is available, then it also loads methods implemented using functions in this package.

To prevent incompatibilities, the package will not load if singular has been already loaded.

 ‣ NumSgpsUseSingularGradedModules( ) ( function )
Tries to load the package GradedModules. If the package is available, then it also loads methods implemented using functions in this package.
It also creates a ring of rationals NumSgpsRationals.