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WeylGroups :: rootCoefficients(RootSystem,Root)

rootCoefficients(RootSystem,Root) -- the coefficients at the simple roots

Synopsis

Description

i1 : R=rootSystemE(8)

o1 = RootSystem{...8...}

o1 : RootSystem
i2 : r1=simpleRoot(R,1)

o2 = |  2 |
     |  0 |
     | -1 |
     |  0 |
     |  0 |
     |  0 |
     |  0 |
     |  0 |

o2 : Root
i3 : r2=simpleRoot(R,2)

o3 = |  0 |
     |  2 |
     |  0 |
     | -1 |
     |  0 |
     |  0 |
     |  0 |
     |  0 |

o3 : Root
i4 : rootCoefficients(R,r1+r2)

o4 = | 1 |
     | 1 |
     | 0 |
     | 0 |
     | 0 |
     | 0 |
     | 0 |
     | 0 |

       8
o4 : QQ