MATLAB: Variable precision arithmetic in ode45 and others

MATLABode45Symbolic Math Toolbox

Is it possible to use vpa in ordinary differential equation solvers like ode45?

Best Answer

Sort of. The internal symbolic engine has two numeric ode routines. At the moment I do not know if there is a matlab level interface to those routines.

You might need to use feval(symengine) to access the routines.

http://www.cfm.brown.edu/people/dobrush/am33/MuPad/MuPad22.html

Related Solutions

MATLAB: Can I use numeric::odesolve as a replacement to ode45

It is possible, by using some magic. See for example,

syms y(t)
%Boundary conditions are required
eqns = {diff(y(t),t) == t*sin(y(t)), y(0) == 2};   %use a cell array! 
numdig = 16;     %number of decimal places to use
digits(numdig);
symLIST = @(varargin)feval(symengine,'DOM_LIST',varargin{:});
symRANGE = @(a,b) feval(symengine, '_range', a, b);
IVP = symLIST(eqns{:});
fields = symLIST(y(t));
IVP = feval(symengine,'numeric::ode2vectorfield', IVP, fields);
syms CK45
method = CK45;
feval(symengine, 'numeric::odesolve', IVP(1), symRANGE(IVP(2),10), IVP(3), method)

You can omit the method parameter from the call.

MATLAB: Not able to solve an ode using dsolve

Consider:

syms y(t)
ode = diff(y,t) ==  -0.127.*(-3.*(log(7e-10.*exp(0.405.*y))).*(y - 0.01)); 
cond1 = y(0) == 0.01;
cond2 = y(0) == 1;
ySol = dsolve(ode)
ysol1 = dsolve(ode,cond1)
ysol2 = dsolve(ode,cond2)

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Related Solutions

MATLAB: Can I use numeric::odesolve as a replacement to ode45

MATLAB: Not able to solve an ode using dsolve

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