MinorsCount -- An option controlling the behavior of isBirational and inverseOfMap (and other functions which call those).

Description

One of the ways to invert a map is to find a nonzero minor of a variant of the jacobialDualMatrix. This function controls how many (randomly chosen) minors to check before switching to another strategy (invovling computing a syzygy). Setting it to zero will mean no minors are checked. If it is left as null (the default), the functions will try to make an educated guess as to how big to make this, depending on varieties you are working with.

See also

• inverseOfMap -- Computes the inverse map of a given birational map between projective varieties. Returns an error if the map is not birational onto its image.

Functions with optional argument named MinorsCount :

• "inverseOfMap(...,MinorsCount=>...)"
• "isBirationalMap(...,MinorsCount=>...)"
• "isBirationalOntoImage(...,MinorsCount=>...)"
• "isEmbedding(...,MinorsCount=>...)"
• "sourceInversionFactor(...,MinorsCount=>...)"