RandomTools
GenerateSimilarODE
create a random differential equation similar to the one given
Calling Sequence
Parameters
Description
Examples
Compatibility
GenerateSimilarODE( eqn )
eqn
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differential equation with one dependent and one independent variable
The GenerateSimilarODE command takes an ordinary differential equation (ODE) eqn with 1 dependent and 1 independent variable and returns a similar ODE in the same variables.
Linear ordinary differential equations with constant coefficients that have order higher than 1 return a linear ordinary differential equations with constant coefficients that have similar roots to the characteristic polynomial of the ODE. Each real root in eqn will have a corresponding real root in the output ODE, each repeated root in eqn will correspond to a repeated root in the output ODE. A pair of complex conjugate roots in eqn will correspond to a pair of complex conjugate roots in the output ODE.
Linear ordinary differential equations with constant coefficients that have order higher than 1 and a forcing function that contains functions that are linearly dependent to the solution of the homogeneous ODE produce an ODE with the similar roots described above and a forcing function that has functions that are linearly dependent to the solutions of the homogeneous output ODE.
Bessel differential equations or differential equations that can be converted into Bessel differential equations return Bessel differential equations or differential equations that can be converted into Bessel differential equations.
Differential equations that when solved produce terminating Legendre polynomials return differential equations that when solved produce terminating Legendre polynomials.
Differential equations that when solved produce terminating Laguerre polynomials return differential equations that when solved produce terminating Laguerre polynomials.
Chebyshev differential equations produce Chebyshev differential equations.
with⁡RandomTools:
ODE1≔%diff⁡y⁡x,x⁢y⁡x+sin⁡x=exp⁡x⁢y⁡x
ODE1≔ⅆⅆxy⁡x⁢y⁡x+sin⁡x=ⅇx⁢y⁡x
GenerateSimilarODE⁡ODE1
4⁢ⅆⅆxy⁡x⁢y⁡x−9⁢cos⁡x=−7⁢ⅇ−6⁢x⁢y⁡x
2nd order linear ODE with constant coefficients with a characteristic polynomial that has real roots.
ODE2≔%diff⁡y⁡x,`$`⁡x,2+%diff⁡y⁡x,x−6⁢y⁡x=0
ODE2≔ⅆ2ⅆx2y⁡x+ⅆⅆxy⁡x−6⁢y⁡x=0
dsolve⁡ODE2
y⁡x=c__1⁢ⅇ2⁢x+c__2⁢ⅇ−3⁢x
newODE2≔GenerateSimilarODE⁡ODE2
newODE2≔19⁢ⅆⅆxy⁡x−ⅆ2ⅆx2y⁡x−90⁢y⁡x=0
dsolve⁡newODE2
y⁡x=c__1⁢ⅇ9⁢x+c__2⁢ⅇ10⁢x
2nd order linear ODE with constant coefficients with a repeated root.
ODE3≔%diff⁡y⁡x,`$`⁡x,2−6⁢%diff⁡y⁡x,x+9⁢y⁡x=0
ODE3≔ⅆ2ⅆx2y⁡x−6⁢ⅆⅆxy⁡x+9⁢y⁡x=0
dsolve⁡ODE3
y⁡x=c__1⁢ⅇ3⁢x+c__2⁢ⅇ3⁢x⁢x
newODE3≔GenerateSimilarODE⁡ODE3
newODE3≔−16⁢ⅆⅆxy⁡x+ⅆ2ⅆx2y⁡x+64⁢y⁡x=0
dsolve⁡newODE3
y⁡x=c__1⁢ⅇ8⁢x+c__2⁢ⅇ8⁢x⁢x
2nd order linear ODE with a pair of complex conjugate roots.
ODE4≔%diff⁡y⁡x,`$`⁡x,2−2⁢%diff⁡y⁡x,x+2⁢y⁡x=0
ODE4≔ⅆ2ⅆx2y⁡x−2⁢ⅆⅆxy⁡x+2⁢y⁡x=0
dsolve⁡ODE4
y⁡x=c__1⁢ⅇx⁢sin⁡x+c__2⁢ⅇx⁢cos⁡x
newODE4≔GenerateSimilarODE⁡ODE4
newODE4≔−20⁢ⅆⅆxy⁡x+ⅆ2ⅆx2y⁡x+101⁢y⁡x=0
dsolve⁡newODE4
y⁡x=c__1⁢ⅇ10⁢x⁢sin⁡x+c__2⁢ⅇ10⁢x⁢cos⁡x
2nd order linear ODE with forcing function that contains a function that is linearly dependent to a solution to the homogeneous ODE.
ODE5≔%diff⁡y⁡x,`$`⁡x,2+%diff⁡y⁡x,x−6⁢y⁡x=x⁢exp⁡2⁢x
ODE5≔ⅆ2ⅆx2y⁡x+ⅆⅆxy⁡x−6⁢y⁡x=x⁢ⅇ2⁢x
dsolve⁡ODE5
y⁡x=ⅇ2⁢x⁢c__2+ⅇ−3⁢x⁢c__1+ⅇ2⁢x⁢x⁢5⁢x−250
newODE5≔GenerateSimilarODE⁡ODE5
newODE5≔−18⁢ⅆⅆxy⁡x−ⅆ2ⅆx2y⁡x−80⁢y⁡x=−10⁢x⁢ⅇ−8⁢x
dsolve⁡newODE5
y⁡x=ⅇ−8⁢x⁢c__2+ⅇ−10⁢x⁢c__1+5⁢x⁢x−1⁢ⅇ−8⁢x2
Bessel differential equation.
ODE6≔x2⁢%diff⁡y⁡x,`$`⁡x,2+x⁢%diff⁡y⁡x,x+x2⁢y⁡x=0
ODE6≔x2⁢ⅆ2ⅆx2y⁡x+x⁢ⅆⅆxy⁡x+x2⁢y⁡x=0
dsolve⁡ODE6
y⁡x=c__1⁢BesselJ⁡0,x+c__2⁢BesselY⁡0,x
newODE6≔GenerateSimilarODE⁡ODE6
newODE6≔x2⁢ⅆ2ⅆx2y⁡x+x⁢ⅆⅆxy⁡x+x2−36⁢y⁡x=0
dsolve⁡newODE6
y⁡x=c__1⁢BesselJ⁡6,x+c__2⁢BesselY⁡6,x
ODE7≔x2⁢%diff⁡y⁡x,`$`⁡x,2+x⁢%diff⁡y⁡x,x+x2−9⁢y⁡x=0
ODE7≔x2⁢ⅆ2ⅆx2y⁡x+x⁢ⅆⅆxy⁡x+x2−9⁢y⁡x=0
dsolve⁡ODE7
y⁡x=c__1⁢BesselJ⁡3,x+c__2⁢BesselY⁡3,x
newODE7≔GenerateSimilarODE⁡ODE7
newODE7≔x2⁢ⅆ2ⅆx2y⁡x+x⁢ⅆⅆxy⁡x+x2−49⁢y⁡x=0
dsolve⁡newODE7
y⁡x=c__1⁢BesselJ⁡7,x+c__2⁢BesselY⁡7,x
ODEs that can be converted to a Bessel differential equation.
ODE8≔x2⁢%diff⁡y⁡x,`$`⁡x,2+2⁢x⁢%diff⁡y⁡x,x+x2⁢y⁡x=0
ODE8≔x2⁢ⅆ2ⅆx2y⁡x+2⁢x⁢ⅆⅆxy⁡x+x2⁢y⁡x=0
dsolve⁡ODE8
y⁡x=c__1⁢sin⁡xx+c__2⁢cos⁡xx
newODE8≔GenerateSimilarODE⁡ODE8
newODE8≔x2⁢ⅆ2ⅆx2y⁡x+3⁢x⁢ⅆⅆxy⁡x+x2−4⁢y⁡x=0
dsolve⁡newODE8
y⁡x=c__1⁢BesselJ⁡5,xx+c__2⁢BesselY⁡5,xx
ODE9≔2⁢x2⁢%diff⁡y⁡x,`$`⁡x,2+x⁢%diff⁡y⁡x,x+x2⁢y⁡x=0
ODE9≔2⁢x2⁢ⅆ2ⅆx2y⁡x+x⁢ⅆⅆxy⁡x+x2⁢y⁡x=0
dsolve⁡ODE9
y⁡x=c__1⁢x14⁢BesselJ⁡14,2⁢x2+c__2⁢x14⁢BesselY⁡14,2⁢x2
newODE9≔GenerateSimilarODE⁡ODE9
newODE9≔5⁢x2⁢ⅆ2ⅆx2y⁡x+x⁢ⅆⅆxy⁡x+x2−4⁢y⁡x=0
dsolve⁡newODE9
y⁡x=c__1⁢x25⁢BesselJ⁡2⁢65,5⁢x5+c__2⁢x25⁢BesselY⁡2⁢65,5⁢x5
Terminating Laguerre polynomials.
ODE10≔x⁢%diff⁡y⁡x,`$`⁡x,2+1−x⁢%diff⁡y⁡x,x+y⁡x=0
ODE10≔x⁢ⅆ2ⅆx2y⁡x+1−x⁢ⅆⅆxy⁡x+y⁡x=0
dsolve⁡ODE10
y⁡x=c__1⁢x−1+c__2⁢x−1⁢Ei1⁡−x+ⅇx
newODE10≔GenerateSimilarODE⁡ODE10
newODE10≔x⁢ⅆ2ⅆx2y⁡x+1−x⁢ⅆⅆxy⁡x+2⁢y⁡x=0
dsolve⁡newODE10
y⁡x=c__1⁢x2−4⁢x+2+c__2⁢x2−4⁢x+2⁢Ei1⁡−x4+x−3⁢ⅇx4
ODE11≔x⁢%diff⁡y⁡x,`$`⁡x,2+1−x⁢%diff⁡y⁡x,x+5⁢y⁡x=0
ODE11≔x⁢ⅆ2ⅆx2y⁡x+1−x⁢ⅆⅆxy⁡x+5⁢y⁡x=0
dsolve⁡ODE11
y⁡x=c__1⁢x5−25⁢x4+200⁢x3−600⁢x2+600⁢x−120+c__2⁢x5−25⁢x4+200⁢x3−600⁢x2+600⁢x−120⁢Ei1⁡−x600+ⅇx⁢x4−24⁢x3+177⁢x2−444⁢x+274600
newODE11≔GenerateSimilarODE⁡ODE11
newODE11≔x⁢ⅆ2ⅆx2y⁡x+1−x⁢ⅆⅆxy⁡x=0
dsolve⁡newODE11
y⁡x=c__1+Ei1⁡−x⁢c__2
Terminating Legendre polynomials.
ODE12≔1−x2⁢%diff⁡y⁡x,`$`⁡x,2−2⁢x⁢%diff⁡y⁡x,x+6⁢y⁡x=0
ODE12≔−x2+1⁢ⅆ2ⅆx2y⁡x−2⁢x⁢ⅆⅆxy⁡x+6⁢y⁡x=0
dsolve⁡ODE12
y⁡x=c__1⁢−3⁢x2+1+c__2⁢3⁢x2−1⁢ln⁡x−12+−3⁢x2+1⁢ln⁡x+12+3⁢x
newODE12≔GenerateSimilarODE⁡ODE12
newODE12≔−x2+1⁢ⅆ2ⅆx2y⁡x−2⁢x⁢ⅆⅆxy⁡x−y⁡x−x2+1=0
dsolve⁡newODE12
y⁡x=c__1⁢x−x2+1+c__2−x2+1
ODE13≔1−x2⁢%diff⁡y⁡x,`$`⁡x,2−2⁢x⁢%diff⁡y⁡x,x+12⁢y⁡x=0
ODE13≔−x2+1⁢ⅆ2ⅆx2y⁡x−2⁢x⁢ⅆⅆxy⁡x+12⁢y⁡x=0
dsolve⁡ODE13
y⁡x=c__1⁢−53⁢x3+x+c__2⁢−19+5⁢x3−3⁢x⁢ln⁡x−124+−5⁢x3+3⁢x⁢ln⁡x+124+5⁢x212
newODE13≔GenerateSimilarODE⁡ODE13
newODE13≔−x2+1⁢ⅆ2ⅆx2y⁡x−2⁢x⁢ⅆⅆxy⁡x+20⁢y⁡x=0
dsolve⁡newODE13
y⁡x=c__1⁢353⁢x4−10⁢x2+1+c__2⁢35⁢x4−30⁢x2+3⁢ln⁡x−16+−35⁢x4+30⁢x2−3⁢ln⁡x+16+35⁢x33−55⁢x9
Chebyshev differential equation.
ODE14≔1−x2⁢%diff⁡y⁡x,`$`⁡x,2−x⁢%diff⁡y⁡x,x+25⁢y⁡x=0
ODE14≔−x2+1⁢ⅆ2ⅆx2y⁡x−x⁢ⅆⅆxy⁡x+25⁢y⁡x=0
dsolve⁡ODE14
y⁡x=c__1x+x2−15+c__2⁢x+x2−15
newODE14≔GenerateSimilarODE⁡ODE14
newODE14≔−x2+1⁢ⅆ2ⅆx2y⁡x−x⁢ⅆⅆxy⁡x+36⁢y⁡x=0
dsolve⁡newODE14
y⁡x=c__1x+x2−16+c__2⁢x+x2−16
The RandomTools[GenerateSimilarODE] command was introduced in Maple 2021.
For more information on Maple 2021 changes, see Updates in Maple 2021.
See Also
HowDoI,WorkWithRandomGenerators
InertForm
rand
RandomTools[Generate]
RandomTools[GenerateSimilar]
randpoly
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