[MathJax on]

10 Various other functions

10.1 File operations

10.1-1 Log2HTML

This function has been transferred from package RCWA.

This function converts the GAP logfile filename to HTML. It appears that the logfile should be in your current directory. The extension of the input file must be *.log. The name of the output file is the same as the one of the input file except that the extension *.log is replaced by *.html. There is a sample CSS file in utils/doc/gaplog.css, which you can adjust to your taste.

gap> LogTo( "triv.log" );
gap> a := 33^5;
39135393
gap> LogTo(); 
gap> Log2HTML( "triv.log" );     

10.2 LaTeX strings

10.2-1 IntOrOnfinityToLaTeX

This function has been transferred from package ResClasses.

IntOrInfinityToLaTeX(n) returns the LaTeX string for n.

gap> IntOrInfinityToLaTeX( 10^3 );
"1000"
gap> IntOrInfinityToLaTeX( infinity );
"\\infty"

10.2-2 LaTeXStringFactorsInt

This function has been transferred from package RCWA.

It returns the prime factorization of the integer n as a string in LaTeX format.

gap> LaTeXStringFactorsInt( Factorial(12) );
"2^{10} \\cdot 3^5 \\cdot 5^2 \\cdot 7 \\cdot 11"

10.3 Conversion to Magma string

10.3-1 ConvertToMagmaInputString

The function ConvertToMagmaInputString( obj [, str] ) attempts to output a string s which can be read into Magma [BCP97] so as to produce the same group in that computer algebra system. In the second form the user specifies the name of the resulting object, so that the output string has the form "str := ...". When obj is a permutation group, the operation PermGroupToMagmaFormat(obj) is called. This function has been taken from other.gi in the main library where it was called MagmaInputString. When obj is a pc-group, the operation PcGroupToMagmaFormat(obj) is called. This function was private code of Max Horn. When obj is a matrix group over a finite field, the operation MatrixGroupToMagmaFormat(obj) is called. This function is a modification of private code of Frank Lübeck.

Hopefully code for other types of group will be added in due course.

These functions should be considered experimental, and more testing is desirable.

gap> ConvertToMagmaInputString( Group( (1,2,3,4,5), (3,4,5) ) );
"PermutationGroup<5|(1,2,3,4,5),\n(3,4,5)>;\n"
gap> ConvertToMagmaInputString( Group( (1,2,3,4,5) ), "c5" );        
"c5:=PermutationGroup<5|(1,2,3,4,5)>;\n"
gap> ConvertToMagmaInputString( DihedralGroup( IsPcGroup, 10 ) );
"PolycyclicGroup< f1,f2 |\nf1^2,\nf2^5,\nf2^f1 = f2^4\n>;\n"
gap> M := GL(2,5);;  Size(M); 
480
gap> s1 := ConvertToMagmaInputString( M );
"F := GF(5);\nP := GL(2,F);\ngens := [\nP![2,0,0,1],\nP![4,1,4,0]\n];\nsub<P |\
 gens>;\n"
gap> Print( s1 );
F := GF(5);
P := GL(2,F);
gens := [
P![2,0,0,1],
P![4,1,4,0]
];
sub<P | gens>;
gap> n1 := [ [ Z(9)^0, Z(9)^0 ], [ Z(9)^0, Z(9) ] ];;
gap> n2 := [ [ Z(9)^0, Z(9)^3 ], [ Z(9)^4, Z(9)^2 ] ];;
gap> N := Group( n1, n2 );;  Size( N );
5760
gap> s2 := ConvertToMagmaInputString( N, "gpN" );;
gap> Print( s2 );
F := GF(3^2);
P := GL(2,F);
w := PrimitiveElement(F);
gens := [
P![ 1, 1, 1,w^1],
P![ 1,w^3, 2,w^2]
];
gpN := sub<P | gens>;

generated by GAPDoc2HTML