# maximalEntry -- maximal absolute value of the entries of the matrix or matrices

## Synopsis

• Usage:
m = maximalEntries C
• Inputs:
• C, , or a Matrix, over ZZ, QQ, or RR
• Outputs:
• m, a list, of the maximal absolute values of the entries in matrices defining the differential

## Description

For each matrix we compute the of maximal absolute value of the entries

 i1 : setRandomSeed "nice example 2"; i2 : C=randomChainComplex({1,1,1},{2,2},Height=>10) 3 5 3 o2 = ZZ <-- ZZ <-- ZZ 0 1 2 o2 : ChainComplex i3 : C.dd 3 5 o3 = 0 : ZZ <------------------------- ZZ : 1 | -14 -7 5 5 3 | | 8 13 1 -17 -21 | | -13 -15 1 18 21 | 5 3 1 : ZZ <------------------- ZZ : 2 | -11 5 -10 | | 26 -29 37 | | 19 -16 23 | | -41 -1 -22 | | 46 -16 38 | o3 : ChainComplexMap i4 : maximalEntry C o4 = {21, 46} o4 : List i5 : B=randomChainComplex({2,2,4,2,5,2,2},{2,3,3,2,3,3},Height=>5) 4 7 10 7 10 8 5 o5 = ZZ <-- ZZ <-- ZZ <-- ZZ <-- ZZ <-- ZZ <-- ZZ 0 1 2 3 4 5 6 o5 : ChainComplex i6 : maximalEntry B o6 = {6, 28, 14, 15, 16, 11} o6 : List i7 : apply(min B..max B,i->rank HH_i(B**QQ)) o7 = (2, 2, 4, 2, 5, 2, 2) o7 : Sequence

## Ways to use maximalEntry :

• "maximalEntry(ChainComplex)"
• "maximalEntry(Matrix)"

## For the programmer

The object maximalEntry is .