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SRdeformations :: preImage

preImage -- Compute the preimage.

Synopsis

Description

Computes the preimage of v under A. If v is not in image A then returns false.

i1 : A=matrix {{1, 0}, {0, 1}, {-1, -1}}

o1 = | 1  0  |
     | 0  1  |
     | -1 -1 |

              3        2
o1 : Matrix ZZ  <--- ZZ
i2 : b=vector {-2,2,0}

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

       3
o2 : ZZ
i3 : v=preImage(A,b)

o3 = | -2 |
     |  2 |

       2
o3 : ZZ
i4 : A*v

o4 = | -2 |
     |  2 |
     |  0 |

       3
o4 : ZZ

Ways to use preImage :