Example 4.  Error analysis.  The Taylor series method of order  [Graphics:Images/TaylorDEMod_gr_75.gif]  allegedly has a Final Global Error (FGE) of order  [Graphics:Images/TaylorDEMod_gr_76.gif].  Hence, the error at the right endpoint should appear to decrease by [Graphics:Images/TaylorDEMod_gr_77.gif] when the number of sub-intervals is doubled. Use the D.E. in exercise 1 and investigate this behavior for  [Graphics:Images/TaylorDEMod_gr_78.gif]  sub-intervals of  [Graphics:Images/TaylorDEMod_gr_79.gif].  
Solution  4.

Notice. The subroutine TayorMeth  stores the values in a list starting with subscript 1 and ending with subscript  [Graphics:../Images/TaylorDEMod_gr_80.gif]. We need only check this last point with the value obtained from the analytic solution.  

[Graphics:../Images/TaylorDEMod_gr_81.gif]
[Graphics:../Images/TaylorDEMod_gr_82.gif] [Graphics:../Images/TaylorDEMod_gr_83.gif]
[Graphics:../Images/TaylorDEMod_gr_84.gif] [Graphics:../Images/TaylorDEMod_gr_85.gif]
[Graphics:../Images/TaylorDEMod_gr_86.gif] [Graphics:../Images/TaylorDEMod_gr_87.gif]
[Graphics:../Images/TaylorDEMod_gr_88.gif] [Graphics:../Images/TaylorDEMod_gr_89.gif]
[Graphics:../Images/TaylorDEMod_gr_90.gif]

Does the error decrease in the fashion [Graphics:../Images/TaylorDEMod_gr_91.gif]?  i.e.  [Graphics:../Images/TaylorDEMod_gr_92.gif] should be [Graphics:../Images/TaylorDEMod_gr_93.gif], etc.
Do the following ratios tend to 16 ?  

[Graphics:../Images/TaylorDEMod_gr_94.gif]

[Graphics:../Images/TaylorDEMod_gr_95.gif]

 {-79.3339, 14.5167, 15.8344, 15.9399}

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2003