Example.
Use fixed point iteration to
find the fixed point(s) for the function.
Solution.
Plot the function and determine graphically that there are two solutions to
the equation.
Will iteration prove successful as a computational tool to numerically find
these two fixed points.
Use fixed point iteration to find a numerical approximation.
First, do the iteration one step at a time.Type each of the following commands
in a separate cell and execute them one at a time.
Now use the FixedPointIteration subroutine to perform the computations.
Are 7 iterations enough to locate the fixed point?
How many decimal places agreement do you see to the equation
?
If it is not sufficient for your purposes you must request more iterations!
Comparison 1. Compare with Mathematica's
built in "FindRoot" subroutine for numerically finding solutions.
Did Mathematica get all of the digits?Why?
There are options to every built in Mathematica subroutine. For FindRoot
it is:
Options[FindRoot]
{AccuracyGoal->Automatic,Compiled->True,DampingFactor->1, Jacobian->Automatic,MaxIterations->15,WorkingPrecision->16}
It is the purpose of numerical analysis to study the last two items "MaxIterations,""WorkingPrecision."
Comparison 2. Compare with Mathematica's
built in "Solve" subroutine for symbolically finding solutions.
Mathematica's answers are "mathematically perfect."
Now investigate fixed point iteration near the other fixed point,.
Now use the FixedPointIteration subroutine to perform the computations.
Remark. You need to look carefully at the
above output and determine what it means !Did it converge ?
The distinguishing property for determining convergence is the size of.
Ifis
near the fixed pointpandthen
the iteration will converge top.
Ifis
near the fixed pointpandthen
the iteration will not converge top.
The distinguishing property for determining convergence is the size of.
Ifis
near the fixed pointandin
the neighborhood, then the iteration will converge to.
Ifis
near the fixed pointandin
the neighborhood, then the iteration will not converge to.
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