Top
Back: boundDes
Forward: maxabs
FastBack:
FastForward:
Up: rootsur_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.12.8.7 allrealst

Procedure from library rootsur.lib (see rootsur_lib).

Usage:
allrealst(p); poly p

Return:
int: 1 if and only if all the roots of p are real, 0 otherwise. Checks by using Sturm's Theorem whether all the roots of p are real

Assume:
p is a univariate polynomial with rational coefficients

Example:
 
LIB "rootsur.lib";
ring r = 0,x,dp;
poly p = (x+2)*(x-1)*(x-5);
allrealst(p);
==> 1
p = p*(x2+1);
allrealst(p);
==> 0
See also: allreal; sturm; sturmha.


Top Back: boundDes Forward: maxabs FastBack: FastForward: Up: rootsur_lib Top: Singular Manual Contents: Table of Contents Index: Index About: About this document
            User manual for Singular version 4-0-3, 2016, generated by texi2html.