compute_KM(group_label, t, k);

Computes the Kramer-Mesner matrix for a given group and for integer parameters t and k (with 0 <= t < k <= d, where d is the degree of the permutation group). The result is written on a file (called KM-file) whose name is generated from the input parameters in the following way:

KM_[group]_t[t]_k[k].txt

where [group] is the label of the group and [t] and [k] stand for the values of t and k, respectively.

Return Values:
This function returns the name of the corresponding KM-file as a string

Example:
let g_label be "PGGL_2_32" from Example 1.

gap> km := compute_KM(g_label, 5, 6);
discreta_batch compute_KM discreta_batch_output.g discreta_tmp PGGL_2_32 PGGL_\
2_32 5 6 1 
"KM_PGGL_2_32_t5_k6.txt"
gap> 
Computes the Kramer-Mesner matrix for t=5, k=6 and the previously constructed group "PGGL_2_32". The KM-file which is created has the name KM_PGGL_2_32_t5_k6.txt. This file looks as follows: KM_PGGL_2_32_t5_k6.txt This file contains the following information:

get_KM_matrix(km, t, k);

Retrieves the KM-matrix for given t and k from the KM-file. t and k must not be the same as when the KM-file was computed but we must have 0 <= t < k <= k0 (where k0 is the value of k when the KM-file was created).

Example:

gap> M := get_KM_matrix(km, 5, 6);
discreta_batch get_KM_matrix KM_PGGL_2_32_t5_k6.txt discreta_batch_output.g di\
screta_tmp 5 6 
[ [ 5, 5, 5, 5, 5, 1, 1, 1, 0, 0, 0, 0, 0 ], 
  [ 0, 4, 4, 8, 0, 0, 0, 0, 4, 4, 4, 0, 0 ], 
  [ 2, 1, 4, 3, 2, 1, 1, 1, 2, 5, 2, 3, 1 ] ]
gap> 


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Last updated: July 26, 1999, Evi Haberberger