ParametricNDSolve
ParametricNDSolve[eqns,u,{x,xmin,xmax},pars]
finds a numerical solution to the ordinary differential equations eqns for the function u with the independent variable x in the range xmin to xmax with parameters pars.
ParametricNDSolve[eqns,u,{x,xmin,xmax},{y,ymin,ymax},pars]
solves the partial differential equations eqns over a rectangular region.
ParametricNDSolve[eqns,u,{x,y}∈Ω,pars]
solves the partial differential equations eqns over the region Ω.
ParametricNDSolve[eqns,u,{t,tmin,tmax},{x,y}∈Ω,pars]
solves the time-dependent partial differential equations eqns over the region Ω.
ParametricNDSolve[eqns,{u1,u2,…},…]
solves for the functions ui.
Details and Options
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- ParametricNDSolve gives results in terms of ParametricFunction objects.
- A specification for the parameters pars of {pspec1,pspec2,…} can be used to specify ranges.
- Possible forms for pspeci are:
-
p p has range Reals or Complexes Element[p,Reals] p has range Reals Element[p,Complexes] p has range Complexes Element[p,{v1,…}] p has discrete range {v1,…} {p,pmin,pmax} p has range - In ParametricNDSolve[eqns,{u1,u2,…},…], ui can be any expression. Typically, ui will depend on the parameters indirectly through the solution of the differential equations but may depend explicitly on the parameters. A ParametricFunction object that will return a list can be obtained using ParametricNDSolve[eqns,{{u1,u2,…}},…] or by using ParametricNDSolveValue[eqns,{u1,u2,…},…].
- Derivatives of the resulting ParametricFunction objects with respect to the parameters are computed using a combination of symbolic and numerical sensitivity methods when possible.
- ParametricNDSolve takes the same options and settings as NDSolve.
- NDSolve and ParametricNDSolve typically solve differential equations by going through several different stages, depending on the type of equations. With Method->{s1->m1,s2->m2,…}, stage si is handled by method mi. The actual stages used and their order are determined by NDSolve, based on the problem to be solved.
- Possible solution stages are the same as for NDSolve, with the addition of:
-
"ParametricCaching" caching of computed solutions "ParametricSensitivity" computation of derivatives with respect to parameters
List of all options
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Examples
open allclose allBasic Examples (3)
Get a parametric solution for y:
Evaluating with a numerical value of a gives an approximate function solution for y:
Plot the solutions for several different values of the parameter:
Get a function of the parameter a that gives the function f at :
This plots the value of f[10] as a function of the parameter a:
Find a value of a for which y[10]=0:
Show the sensitivity of the solution of a differential equation to parameters:
Scope (5)
Parameter Dependence (3)
ParametricNDSolve returns a substitution to a ParametricFunction object:
Plot solutions for values of ranging from
to
:
Initial conditions can be specified as parameters:
Plot solutions with with
for values of
ranging from
to
:
Plot solutions with with
for values of
ranging from
to
:
Differential equation coefficients and boundary conditions can be specified as parameters:
Plot solutions with for values of
ranging from
to
and with
and
:
Parameter Sensitivity (2)
Solve the classical harmonic oscillator with parametric amplitude :
Plot the solution for and several nearby values of
:
The sensitivity of with respect to
is by definition
. Plot the sensitivity at
:
Plot the sensitivity as a band around the solution
for
:
Sensitivity analysis of a differential equation with multiple parameters:
Plot the sensitivity with respect to the initial condition at
,
:
Plot the sensitivity with respect to the initial condition at
,
:
Generalizations & Extensions (1)
Solve ,
for various values of WorkingPrecision and plot the error:
Options (2)
Method (2)
ParametricCaching (1)
Applications (10)
Parameter Sweeps (4)
Find an initial value for which the solution
of a differential equation will have
:
Compare to nearby values of the parameter s:
Find several solutions to the boundary value problem ,
,
. First consider several possible values for
:
Run a parameter sweep to determine nontrivial solution values of :
Using approximate initial values from the graph above:
Plot the solutions that were found:
Find all eigenvalues and eigenfunctions
for
with
. Start by exploring the possible parameter values:
Find the value of for which the solution of
,
has minimal arc length from
to
. Begin by plotting the solutions for values of
ranging from 0 to 1:
Plot versus the arc length of the solution:
The minimum arc length solution for seems to occur at
:
Find the local minimum, which appears near :
Plot the corresponding solution of (locally) minimal arc length together with some nearby solutions:
Parameter Sensitivities (4)
Perturb a parameter in a differential equation and view several of the resulting perturbed solutions:
Plotting the sensitivity solutions gives qualitatively the same result:
Simulate an inverted pendulum stabilized by an oscillating base:
Sensitivity of with respect to the amplitude a increases with time:
Parametric dependence of the heat equation ,
:
Plot the corresponding sensitivity bands:
Indicate sensitivity to a and c by changing the color of the solution surface:
Find the sensitivity of the Lorenz equations to a parameter:
Parameter Fitting (2)
Sample the solution of a differential equation and add noise:
Fit a trigonometric model to the noisy data:
A quadratic model is a better fit:
Find the parameters that make the solution of a differential equation the best fit to data:
The data comes from a cooling body, so use Newton's law of cooling:
Properties & Relations (1)
Use SystemModelParametricSimulate to simulate larger hierarchical system models:
Simulate with two sets of resistor and spring damper parameters:
Text
Wolfram Research (2012), ParametricNDSolve, Wolfram Language function, https://reference.wolfram.com/language/ref/ParametricNDSolve.html (updated 2014).
CMS
Wolfram Language. 2012. "ParametricNDSolve." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2014. https://reference.wolfram.com/language/ref/ParametricNDSolve.html.
APA
Wolfram Language. (2012). ParametricNDSolve. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ParametricNDSolve.html