modelSphBessel_jzeros

Zeros of Spherical Bessel functions

Extends from Icons.Example (Icon for runnable examples).

Information

Determination of zeros of spherical Bessel functions, j0(xi)=0 and j1(xi)=0, via Modelica/GSL and via direct GSL routines to compare.

Plots of zeroj0.y and zeroj1.y should display steps with lower-right corners at ( t , y ) = ( xi,Modelica , xi,GSL ) and such values should be equal at these corners.

The location of the zeros of spherical Bessel functions is a crucial element in some boundary value problems involving spherical symmetry and this example shows how the 'Bessel_zeroJnu' block (with nu=n+1/2; n integer) provides said info quickly.

As not all special functions' zeros are provided via GSL routines, the displayed use of Modelica's zero-crossing logical blocks could be useful for finding such information for these other functions.

Components

TypeNameDefaultDescription
Modelica.Blocks.Logical.ZeroCrossingzeroCrossj0
Modelica.Blocks.Logical.ZeroCrossingzeroCrossj1
Modelica.Blocks.MathInteger.TriggeredAddtrigAddj0
Modelica.Blocks.MathInteger.TriggeredAddtrigAddj1
Modelica.Blocks.Sources.IntegerConstantintegerConstant
Modelica.Blocks.Sources.BooleanConstantenZj0
Modelica.Blocks.Sources.BooleanConstantenZj1
GNU_ScientificLibrary.Blocks.specfunc.SphBessel_jlsphBessel_j0
GNU_ScientificLibrary.Blocks.specfunc.SphBessel_jlsphBessel_j1
GNU_ScientificLibrary.Blocks.specfunc.Bessel_zeroJnuzeroj0
Blocks.specfunc.Bessel_zeroJnuzeroj1
Modelica.Blocks.Sources.Rampramp