image(RationalMap,ZZ) -- closure of the image of a rational map

Synopsis

• Function: image

• Usage:

  image Phi

  image(Phi,d)

• Inputs:
  • Phi, a rational map
  • d, an integer
• Outputs:
  • an ideal, the ideal defining the closure of the image of Phi, or its degree d homogeneous component if d is passed

Description

This computation is done through the kernel of a ring map representing the rational map. See kernel(RingMap) and kernel(RingMap,ZZ) for more details.

See also

• kernel(RingMap,ZZ)
• kernel(RingMap) -- kernel of a ringmap
• image(RationalMap,String) -- closure of the image of a rational map using the F4 algorithm (experimental)