Error, (in evalf/RootOf) there are ambiguous values encoded in RootOf(...) - Maple Programming Help

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Error, (in evalf/RootOf) there are ambiguous values encoded in RootOf(...)

Error, (in convert/RootOf) there is ambiguity in RootOf(...)

 

Description

Examples

Description

The error occurs when evalf or convert are passed expressions that have ambiguity in regards to specification of roots.

Examples

Example 1

The numerical approximation of 12 used as a root selector is not helpful in distinguishing between the two roots, 1252, 12+52,  since both roots are a distance of exactly 52 from 12.

eRootOfx2x1,12

e:=RootOf_Z2_Z1,12

(2.1)

evalfe

Error, (in evalf/RootOf) there are ambiguous values encoded in RootOf(_Z^2-_Z-1, 1/2)

 

Example 2

 

r1RootOf_Z22,0

r1:=RootOf_Z22,0

(2.2)

r2RootOf_Z22,index=1

r2:=RootOf_Z22,index=1

(2.3)

The numeric selector, 0, is not sufficient to distinguish whether r1 is the positive or negative root. Therefore, the following gcd computation is ambiguous: if r1 represents the positive root, then the GCD is x2, but if r1 represents the negative root, then the GCD is 1. Hence an error is raised:

gcdxr1,xr2;

Error, (in evalf/RootOf) there are ambiguous values encoded in RootOf(_Z^2-2, 0)

 

Example 3

convertRootOfx2x1,12,RootOf,form=index

Error, (in convert/RootOf) there is ambiguity in RootOf(_Z^2-_Z-1, 1/2)

 

See Also

examples,RootOf