[giac] fix for rsolve(u(n+2)=3*u(n+1)+2*u(n),u(n),[u(1)=4,u(2)=14])

git-svn-id: https://dev.geogebra.org/svn/trunk/geogebra/giac@70115 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
geogebra · May 16, 2023 · 3b9a8f2 · 3b9a8f2
1 parent f50ceef
commit 3b9a8f2
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Showing 3 changed files with 4 additions and 4 deletions.
diff --git a/src/giac/cpp/csturm.cc b/src/giac/cpp/csturm.cc
@@ -3108,7 +3108,7 @@ void add(mpfr_t & rr,mpfr_t & ri,const gen & Pi,int nbits,long & loss,long & siz
 
 // find r=P(x) and r1=diff(P)(x)
 // returns largest number of bits of mantissa in intermediate computations
-long horner2_mpfr(const vdbl & P,dbl x,dbl & r,dbl & r1,int nbits,long & size,bool pdiff){
+long horner2_mpfr(const vdbl & P,const dbl & x,dbl & r,dbl & r1,int nbits,long & size,bool pdiff){
   if (P.empty())
     return 0;
   long loss=0;
@@ -3740,7 +3740,7 @@ int aberth_mpfr(const vdbl & P0,bool realpoly,int & nbits,int N,double eps,vdbl
             ){
           for (size_t j=0;j<R.size();++j){
             R[j] += dr;
-            if (!isolate)
+            if (!isolate && eps>1e-14)
               R[j]=evalf_double(R[j],1,contextptr);
           }
           return 2;

diff --git a/src/giac/cpp/solve.cc b/src/giac/cpp/solve.cc
@@ -4323,7 +4323,7 @@ namespace giac {
     vecteur B,R(x);
     gen rep;
     if (A.size()==2 && x.size()==2){
-      gen a00=A[0][0];
+      gen a00=A[0][0]; a00=simplify(a00,contextptr);
       if (is_zero(a00,contextptr))
 	B=makevecteur(A[1],A[0]);
       else 

diff --git a/src/giac/cpp/usual.cc b/src/giac/cpp/usual.cc
@@ -7564,7 +7564,7 @@ namespace giac {
       if (a2.type==_INT_)
         return a1.eval(a2.val,contextptr);
       a1=eval(a1,eval_level(contextptr),contextptr);
-      if (a2.type==_STRNG && a2._STRNGptr->size()==4){
+      if (a1.type==_STRNG && a2.type==_STRNG && a2._STRNGptr->size()==4){
         const char * ptr=a2._STRNGptr->c_str();
         if (ptr[0]=='a' && ptr[1]=='s' && ptr[2]=='m' && ptr[3]==platform_type && a1.type==_STRNG){
           const char * ptr=a1._STRNGptr->c_str();