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FirstNonZero, FirstNonZeroPos |
Syntax |
FirstNonZero(V:VECTOR):POLY FirstNonZeroPos(V:VECTOR):POLY |
Summary |
the first non-zero entry in a vector |
Description |
The first function returns the first non-zero entry of V. The second function returns the index of the first non-zero entry of V. If either function is handed a zero vector then an error is signalled. |
Example |
Use R ::= Q[x,y,z]; V := Vector(0,0,x^2+yz,0,z^2); FirstNonZero(V); x^2 + yz ------------------------------- FirstNonZeroPos(V); 3 ------------------------------- V[FirstNonZeroPos(V)]; x^2 + yz ------------------------------- |
See also: |