TomAllen/Testing/Testing01

NB. ... script Signature1.ijs ...

gXo1=:>@(0{[)
gXo2=:>@(1{[)
gXa0=:>@(2{[)
gXb0=:>@(3{[)

gXbox0R=:>@(0{])
gXbox1R=:>@(1{])

NB. ... from 'numeric' ...

gXsteps=:{.+(1&{-{.)*(i.@>:%])@{:

NB. ... tolerant 'set zero' (see 'Essays/Tolerant Comparison') ...

gXtsz=:$@]$[0:`(I.@([>!.0|@]))`]},@]
gXts0=:(2^_44)&gXtsz

NB. ... tolerant 'equal' (see 'Essays/Tolerant Comparison') ...

gXteq=:*./@,@((gXbox0R|@:-gXbox1R)<:!.0[*gXbox0R>.&:|gXbox1R)

NB. ... verbs useful for tolerant comparison ...

gXnzmin  =:<./@:|@((0<!.0|)#])@,
gXnzmax  =:>./@:|@((0<!.0|)#])@,
gXnzcount=:+/@(0<!.0|)@,

NB. ... axes sum ...

gXsmx=:+/@(*"1)"1 _

NB. ... trig verbs ...

sin=:1&o.
cos=:2&o.
arctant1=:(1p1+_3&o.@({:%{.))`( (2p1+_3&o.@({:%{.))`(_3&o.@({:%{.))@.(>:&0@{:) )@.(>&0@{.)
arctant0=:3r2p1"_`( 1r2p1"_)@.(>&0@{:)`0:@.(=&0@{:)
arctan  =:arctant1`arctant0@.(=&0@{.)"1



\begin{gather*}
\intertext
{\texttt
{... Bessel's equation ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
+
x
\frac{dy}{dx}
+
(
x^2
-
p^2
)
y
=
0
\end{split}    \\
\intertext
{\texttt
{... solution of the form ...
}
}
\begin{split}
y
=
\sum_{n=0}^\infty
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... where ...
\newline
...
\newline
... $a_0 \neq 0$ ...
\newline
... $a_n=0$ for all negative $n$ ...
\newline
... $\rho$ is allowed to be any number ...
\newline
...
\newline
... so ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
(n+\rho-1)
x^{n+\rho}    \\
x
\frac{dy}{dx}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
x^{n+\rho}    \\
x^2
y
=
&
\sum_{n=0}^\infty
a_{n-2}
x^{n+\rho}    \\
-
p^2
y
=
&
\sum_{n=0}^\infty
-
p^2
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
\sum_{n=0}^\infty
\biggl(
a_n
(n+\rho)
(n+\rho-1)
+
a_n
(n+\rho)
+
a_{n-2}
-
p^2
a_n
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\begin{split}
\sum_{n=0}^\infty
\biggl(
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\intertext
{\texttt
{... then ...
\newline
... for all $n$ ...
}
}
\begin{split}
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
=
0
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
a_n
=
-
\frac
{
1
}
{
(n+\rho)^2
-
p^2
}
a_{n-2}
\end{split}    \\
\intertext
{\texttt
{... therefore ...
\newline
...
\newline
... $n=0$ ...
}
}
\begin{split}
\Bigl(
(0+\rho)^2
-
p^2
\Bigr)
a_0
+
0
=
0
\end{split}    \\
\begin{split}
\rho
=
\pm
p
\end{split}    \\
\intertext
{\texttt
{... and ...
\newline
... (provided denominator does not vanish) ...
\newline
...
\newline
... $n=1$ ...
}
}
\begin{align*}
\begin{split}
a_1
=
&
-
\frac
{
1
}
{
(1+\rho)^2
-
\rho^2
}
a_{-1}    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=2$ ...
}
}
\begin{split}
a_2
=
&
-
\frac
{
1
}
{
(2+\rho)^2
-
\rho^2
}
a_0    \\
=
&
-
\frac
{
1
}
{
2
(2\rho+2)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=3$ ...
}
}
\begin{split}
a_3
=
&
-
\frac
{
1
}
{
(3+\rho)^2
-
\rho^2
}
a_1    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=4$ ...
}
}
\begin{split}
a_4
=
&
-
\frac
{
1
}
{
(4+\rho)^2
-
\rho^2
}
a_2    \\
=
&
\frac
{
1
}
{
(2)
(4)
(2\rho+2)
(2\rho+4)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=5$ ...
}
}
\begin{split}
a_5
=
&
-
\frac
{
1
}
{
(5+\rho)^2
-
\rho^2
}
a_3    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=6$ ...
}
}
\begin{split}
a_6
=
&
-
\frac
{
1
}
{
(6+\rho)^2
-
\rho^2
}
a_4    \\
=
&
-
\frac
{
1
}
{
(2)
(4)
(6)
(2\rho+2)
(2\rho+4)
(2\rho+6)
}
a_0
\end{split}    \\
\end{align*}
\intertext
{\texttt
{... etc ...
}
}
\end{gather*}





\begin{gather*}
\intertext
{\texttt
{... Bessel's equation ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
+
x
\frac{dy}{dx}
+
(
x^2
-
p^2
)
y
=
0
\end{split}    \\
\intertext
{\texttt
{... solution of the form ...
}
}
\begin{split}
y
=
\sum_{n=0}^\infty
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... where ...
\newline
...
\newline
... $a_0 \neq 0$ ...
\newline
... $a_n=0$ for all negative $n$ ...
\newline
... $\rho$ is allowed to be any number ...
\newline
...
\newline
... so ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
(n+\rho-1)
x^{n+\rho}    \\
x
\frac{dy}{dx}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
x^{n+\rho}    \\
x^2
y
=
&
\sum_{n=0}^\infty
a_{n-2}
x^{n+\rho}    \\
-
p^2
y
=
&
\sum_{n=0}^\infty
-
p^2
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
\sum_{n=0}^\infty
\biggl(
a_n
(n+\rho)
(n+\rho-1)
+
a_n
(n+\rho)
+
a_{n-2}
-
p^2
a_n
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\begin{split}
\sum_{n=0}^\infty
\biggl(
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\intertext
{\texttt
{... then ...
\newline
... for all $n$ ...
}
}
\begin{split}
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
=
0
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
a_n
=
-
\frac
{
1
}
{
(n+\rho)^2
-
p^2
}
a_{n-2}
\end{split}    \\
\intertext
{\texttt
{... therefore ...
\newline
...
\newline
... $n=0$ ...
}
}
\begin{split}
\Bigl(
(0+\rho)^2
-
p^2
\Bigr)
a_0
+
0
=
0
\end{split}    \\
\begin{split}
\rho
=
\pm
p
\end{split}    \\
\intertext
{\texttt
{... and ...
\newline
... (provided denominator does not vanish) ...
\newline
...
\newline
... $n=1$ ...
}
}
\begin{align*}
\begin{split}
a_1
=
&
-
\frac
{
1
}
{
(1+\rho)^2
-
\rho^2
}
a_{-1}    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=2$ ...
}
}
\begin{split}
a_2
=
&
-
\frac
{
1
}
{
(2+\rho)^2
-
\rho^2
}
a_0    \\
=
&
-
\frac
{
1
}
{
2
(2\rho+2)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=3$ ...
}
}
\begin{split}
a_3
=
&
-
\frac
{
1
}
{
(3+\rho)^2
-
\rho^2
}
a_1    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=4$ ...
}
}
\begin{split}
a_4
=
&
-
\frac
{
1
}
{
(4+\rho)^2
-
\rho^2
}
a_2    \\
=
&
\frac
{
1
}
{
(2)
(4)
(2\rho+2)
(2\rho+4)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=5$ ...
}
}
\begin{split}
a_5
=
&
-
\frac
{
1
}
{
(5+\rho)^2
-
\rho^2
}
a_3    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=6$ ...
}
}
\begin{split}
a_6
=
&
-
\frac
{
1
}
{
(6+\rho)^2
-
\rho^2
}
a_4    \\
=
&
-
\frac
{
1
}
{
(2)
(4)
(6)
(2\rho+2)
(2\rho+4)
(2\rho+6)
}
a_0
\end{split}    \\
\end{align*}
\intertext
{\texttt
{... etc ...
}
}
\end{gather*}





\begin{gather*}
\intertext
{\texttt
{... Bessel's equation ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
+
x
\frac{dy}{dx}
+
(
x^2
-
p^2
)
y
=
0
\end{split}    \\
\intertext
{\texttt
{... solution of the form ...
}
}
\begin{split}
y
=
\sum_{n=0}^\infty
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... where ...
\newline
...
\newline
... $a_0 \neq 0$ ...
\newline
... $a_n=0$ for all negative $n$ ...
\newline
... $\rho$ is allowed to be any number ...
\newline
...
\newline
... so ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
(n+\rho-1)
x^{n+\rho}    \\
x
\frac{dy}{dx}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
x^{n+\rho}    \\
x^2
y
=
&
\sum_{n=0}^\infty
a_{n-2}
x^{n+\rho}    \\
-
p^2
y
=
&
\sum_{n=0}^\infty
-
p^2
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
\sum_{n=0}^\infty
\biggl(
a_n
(n+\rho)
(n+\rho-1)
+
a_n
(n+\rho)
+
a_{n-2}
-
p^2
a_n
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\begin{split}
\sum_{n=0}^\infty
\biggl(
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\intertext
{\texttt
{... then ...
\newline
... for all $n$ ...
}
}
\begin{split}
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
=
0
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
a_n
=
-
\frac
{
1
}
{
(n+\rho)^2
-
p^2
}
a_{n-2}
\end{split}    \\
\intertext
{\texttt
{... therefore ...
\newline
...
\newline
... $n=0$ ...
}
}
\begin{split}
\Bigl(
(0+\rho)^2
-
p^2
\Bigr)
a_0
+
0
=
0
\end{split}    \\
\begin{split}
\rho
=
\pm
p
\end{split}    \\
\intertext
{\texttt
{... and ...
\newline
... (provided denominator does not vanish) ...
\newline
...
\newline
... $n=1$ ...
}
}
\begin{align*}
\begin{split}
a_1
=
&
-
\frac
{
1
}
{
(1+\rho)^2
-
\rho^2
}
a_{-1}    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=2$ ...
}
}
\begin{split}
a_2
=
&
-
\frac
{
1
}
{
(2+\rho)^2
-
\rho^2
}
a_0    \\
=
&
-
\frac
{
1
}
{
2
(2\rho+2)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=3$ ...
}
}
\begin{split}
a_3
=
&
-
\frac
{
1
}
{
(3+\rho)^2
-
\rho^2
}
a_1    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=4$ ...
}
}
\begin{split}
a_4
=
&
-
\frac
{
1
}
{
(4+\rho)^2
-
\rho^2
}
a_2    \\
=
&
\frac
{
1
}
{
(2)
(4)
(2\rho+2)
(2\rho+4)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=5$ ...
}
}
\begin{split}
a_5
=
&
-
\frac
{
1
}
{
(5+\rho)^2
-
\rho^2
}
a_3    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=6$ ...
}
}
\begin{split}
a_6
=
&
-
\frac
{
1
}
{
(6+\rho)^2
-
\rho^2
}
a_4    \\
=
&
-
\frac
{
1
}
{
(2)
(4)
(6)
(2\rho+2)
(2\rho+4)
(2\rho+6)
}
a_0
\end{split}    \\
\end{align*}
\intertext
{\texttt
{... etc ...
}
}
\end{gather*}





\begin{gather*}
\intertext
{\texttt
{... Bessel's equation ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
+
x
\frac{dy}{dx}
+
(
x^2
-
p^2
)
y
=
0
\end{split}    \\
\intertext
{\texttt
{... solution of the form ...
}
}
\begin{split}
y
=
\sum_{n=0}^\infty
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... where ...
\newline
...
\newline
... $a_0 \neq 0$ ...
\newline
... $a_n=0$ for all negative $n$ ...
\newline
... $\rho$ is allowed to be any number ...
\newline
...
\newline
... so ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
(n+\rho-1)
x^{n+\rho}    \\
x
\frac{dy}{dx}
=
&
\sum_{n=0}^\infty
a_n
(n+\rho)
x^{n+\rho}    \\
x^2
y
=
&
\sum_{n=0}^\infty
a_{n-2}
x^{n+\rho}    \\
-
p^2
y
=
&
\sum_{n=0}^\infty
-
p^2
a_n
x^{n+\rho}
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
\sum_{n=0}^\infty
\biggl(
a_n
(n+\rho)
(n+\rho-1)
+
a_n
(n+\rho)
+
a_{n-2}
-
p^2
a_n
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\begin{split}
\sum_{n=0}^\infty
\biggl(
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
\biggr)
x^{n+\rho}
=
0
\end{split}    \\
\intertext
{\texttt
{... then ...
\newline
... for all $n$ ...
}
}
\begin{split}
\Bigl(
(n+\rho)^2
-
p^2
\Bigr)
a_n
+
a_{n-2}
=
0
\end{split}    \\
\intertext
{\texttt
{... and ...
}
}
\begin{split}
a_n
=
-
\frac
{
1
}
{
(n+\rho)^2
-
p^2
}
a_{n-2}
\end{split}    \\
\intertext
{\texttt
{... therefore ...
\newline
...
\newline
... $n=0$ ...
}
}
\begin{split}
\Bigl(
(0+\rho)^2
-
p^2
\Bigr)
a_0
+
0
=
0
\end{split}    \\
\begin{split}
\rho
=
\pm
p
\end{split}    \\
\intertext
{\texttt
{... and ...
\newline
... (provided denominator does not vanish) ...
\newline
...
\newline
... $n=1$ ...
}
}
\begin{align*}
\begin{split}
a_1
=
&
-
\frac
{
1
}
{
(1+\rho)^2
-
\rho^2
}
a_{-1}    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=2$ ...
}
}
\begin{split}
a_2
=
&
-
\frac
{
1
}
{
(2+\rho)^2
-
\rho^2
}
a_0    \\
=
&
-
\frac
{
1
}
{
2
(2\rho+2)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=3$ ...
}
}
\begin{split}
a_3
=
&
-
\frac
{
1
}
{
(3+\rho)^2
-
\rho^2
}
a_1    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=4$ ...
}
}
\begin{split}
a_4
=
&
-
\frac
{
1
}
{
(4+\rho)^2
-
\rho^2
}
a_2    \\
=
&
\frac
{
1
}
{
(2)
(4)
(2\rho+2)
(2\rho+4)
}
a_0
\end{split}    \\
\intertext
{\texttt
{... $n=5$ ...
}
}
\begin{split}
a_5
=
&
-
\frac
{
1
}
{
(5+\rho)^2
-
\rho^2
}
a_3    \\
=
&
0
\end{split}    \\
\intertext
{\texttt
{... $n=6$ ...
}
}
\begin{split}
a_6
=
&
-
\frac
{
1
}
{
(6+\rho)^2
-
\rho^2
}
a_4    \\
=
&
-
\frac
{
1
}
{
(2)
(4)
(6)
(2\rho+2)
(2\rho+4)
(2\rho+6)
}
a_0
\end{split}    \\
\end{align*}
\intertext
{\texttt
{... etc ...
}
}
\end{gather*}



\begin{gather*}
\intertext
{\texttt
{...
\newline
... when $\rho$ is a nonnegative integer ...
\newline
... simplify by use of factorials ...
\newline
...
}
}
\begin{split}
y
=
&
a_0
x^{\rho}
\biggl[
1
-
\frac
{
x^2
}
{
(2)
(2\rho+2)
}
+
\frac
{
x^4
}
{
(2)
(4)
(2\rho+2)
(2\rho+4)
}
-
\dotsb
\biggr]    \\
=
&
a_0
x^{\rho}
\biggl[
1
-
\frac
{
(
\frac{x}{2}
)^2
}
{
(1)
(\rho+1)
}
+
\frac
{
(
\frac{x}{2}
)^4
}
{
(1)
(2)
(\rho+1)
(\rho+2)
}
-
\dotsb
\biggr]    \\
=
&
a_0
\rho!
x^{\rho}
\biggl[
\frac
{
1
}
{
(0!)
\rho!
}
-
\frac
{
(
\frac{x}{2}
)^2
}
{
(1!)
(\rho+1)!
}
+
\frac
{
(
\frac{x}{2}
)^4
}
{
(2!)
(\rho+2)!
}
-
\dotsb
\biggr]    \\
=
&
a_0
\rho!
2^{\rho}
\Bigl(
\frac{x}{2}
\Bigr)^\rho
\biggl[
\frac
{
1
}
{
(0!)
\rho!
}
-
\frac
{
(
\frac{x}{2}
)^2
}
{
(1!)
(\rho+1)!
}
+
\frac
{
(
\frac{x}{2}
)^4
}
{
(2!)
(\rho+2)!
}
-
\dotsb
\biggr]    \\
=
&
a_0
\rho!
2^{\rho}
\biggl[
\frac
{
(
\frac{x}{2}
)^\rho
}
{
(0!)
\rho!
}
-
\frac
{
(
\frac{x}{2}
)^{2+\rho}
}
{
(1!)
(\rho+1)!
}
+
\frac
{
(
\frac{x}{2}
)^{4+\rho}
}
{
(2!)
(\rho+2)!
}
-
\dotsb
\biggr]    \\
=
&
a_0
\rho!
2^{\rho}
\sum_{n=0}^\infty
\frac
{
(-1)^n
(
\frac{x}{2}
)^{2n+\rho}
}
{
n!
(\rho+n)!
}    \\
=
&
a_0
\rho!
2^{\rho}
J_{\rho}(x)
\end{split}    \\
\intertext
{\texttt
{... where $J_{\rho}(x)$ is called the Bessel function of order $\rho$ ...
\newline
...
}
}
\end{gather*}

NB. ... script Signature1.ijs (continued) ...

NB. ... when a0=1 ...

bSrhoG  =:>@(0{[)
bSderivG=:>@(1{[)
bSlimitG=:>@(2{[)

bSrhoR  =:>@(0{])
bSderivR=:>@(1{])
bSlimitR=:>@(2{])
bSsignR =:>@(3{])
bSxR    =:>@(4{])
bSnR    =:>@(5{])
bSmltR  =:>@(6{])
bStermR =:>@(7{])
bStotR  =:>@(8{])

bSrhoL  =:>@(0{[)
bSderivL=:>@(1{[)
bSlimitL=:>@(2{[)
bSsignL =:>@(3{[)
bSxL    =:>@(4{[)
bSnL    =:>@(5{[)
bSmltL  =:>@(6{[)
bStermL =:>@(7{[)
bStotL  =:>@(8{[)

NB. ... initial term ...

bSinitd0=:]^bSrhoG
bSinitd1=:bSrhoG*]^bSrhoG-1:
bSinitd2=:bSrhoG*(bSrhoG-1:)*]^bSrhoG-2:
bSinitd3=:bSrhoG*(bSrhoG-1:)*(bSrhoG-2:)*]^bSrhoG-3:
bSinitd4=:bSrhoG*(bSrhoG-1:)*(bSrhoG-2:)*(bSrhoG-3:)*]^bSrhoG-4:

NB. ... subsequent terms ...

bStermd0Mlt=:-@bSsignL*]
bStermd0Pwr=:(bSnL+2:)+bSrhoL
bStermd0   =:bStermd0Mlt*bSxL^bStermd0Pwr

bStermd1Mlt=:-@bSsignL*]*((bSnL+2:)+bSrhoL)
bStermd1Pwr=:(bSnL+2:)+bSrhoL-1:
bStermd1   =:bStermd1Mlt*bSxL^bStermd1Pwr

bStermd2Mlt=:-@bSsignL*]*((bSnL+2:)+bSrhoL)*((bSnL+2:)+bSrhoL-1:)
bStermd2Pwr=:(bSnL+2:)+bSrhoL-2:
bStermd2   =:bStermd2Mlt*bSxL^bStermd2Pwr

bStermd3Mlt=:-@bSsignL*]*((bSnL+2:)+bSrhoL)*((bSnL+2:)+bSrhoL-1:)*((bSnL+2:)+bSrhoL-2:)
bStermd3Pwr=:(bSnL+2:)+bSrhoL-3:
bStermd3   =:bStermd3Mlt*bSxL^bStermd3Pwr

bStermd4Mlt=:-@bSsignL*]*((bSnL+2:)+bSrhoL)*((bSnL+2:)+bSrhoL-1:)*((bSnL+2:)+bSrhoL-2:)*((bSnL+2:)+bSrhoL-3:)
bStermd4Pwr=:(bSnL+2:)+bSrhoL-4:
bStermd4   =:bStermd4Mlt*bSxL^bStermd4Pwr

NB. ... verbs ...

bSinpInit=:bSinitd0`bSinitd1`bSinitd2`bSinitd3`bSinitd4@.bSderivG
bSinp    =:(bSrhoG;bSderivG;bSlimitG;1;];0;1;(];])@bSinpInit)"1 0

bSmult=:%@((bSnR+2:)*(2*bSrhoR)+bSnR+2:)*bSmltR

bSnextTerm=:bStermd0`bStermd1`bStermd2`bStermd3`bStermd4@.bSderivL
bSnext    =:bSrhoL;bSderivL;bSlimitL;-@bSsignL;bSxL;(bSnL+2:);];bSnextTerm([;[+])bStotL

NB. ... Bessel ...

bSbssl=:bStotR"1@:(]`(] bSnext bSmult)@.((bSlimitR<|@bStermR)+.0(=!.0)bStermR)^:_"1)@:bSinp
NB. ... plot (ijs) ...

NB. ... for example ...
NB. ... using p=0.75 and p=-0.75 ...

load 'plot'
pd (];( 0.75;0;(2^_44)"_)bSbssl]) gXsteps 0.01 11.62 101
pd (];(_0.75;0;(2^_44)"_)bSbssl]) gXsteps 0.5  11.62 101
pd 'pdf'
pd 'show'

graphic01.jpg

... real solutions for \rho=0.75 and \rho=-0.75 ...

NB. ... execute (ijx) ...

NB. ... check derivatives ...
NB. ... for example, using p=2 ...

   (((2;1;2^_44"_)bSbssl])((2^_19)gXteq[;])((2;0;2^_44"_)bSbssl]) D.1)"0 gXsteps _11.62 11.62 21
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

   (((2;2;2^_44"_)bSbssl])((2^_14)gXteq[;])((2;1;2^_44"_)bSbssl]) D.1)"0 gXsteps _11.62 11.62 21
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

   (((2;3;2^_44"_)bSbssl])((2^_18)gXteq[;])((2;2;2^_44"_)bSbssl]) D.1)"0 gXsteps _11.62 11.62 21
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

   (((2;4;2^_44"_)bSbssl])((2^_17)gXteq[;])((2;3;2^_44"_)bSbssl]) D.1)"0 gXsteps _11.62 11.62 21
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1



\begin{gather*}
\intertext
{\texttt
{... Bessel's equation ...
}
}
\begin{split}
x^2
\frac{d^2y}{d^2x}
+
x
\frac{dy}{dx}
+
(
x^2
-
p^2
)
y
=
0
\end{split}    \\
\end{gather*}

NB. ... execute (ijx) ...

NB. ... for example ...
NB. ... using p=0.75 ...

   p1a1t1=:(]^2:)*(0.75;2;(2^_44)"_)bSbssl]
   p1a1t2=:]*(0.75;1;(2^_44)"_)bSbssl]
   p1a1t3=:((]^2:)-0.75^2:)*(0.75;0;(2^_44)"_)bSbssl]
   p1a1  =:(p1a1t1+p1a1t2+p1a1t3)"0

   (0=!.0])@((2^_33)&gXtsz@:p1a1) gXsteps _11.62 11.62 21
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

NB. ... and ...
NB. ... using p=-0.75 ...

   p1a2t1=:(]^2:)*(_0.75;2;(2^_44)"_)bSbssl]
   p1a2t2=:]*(_0.75;1;(2^_44)"_)bSbssl]
   p1a2t3=:((]^2:)-_0.75^2:)*(_0.75;0;(2^_44)"_)bSbssl]
   p1a2  =:(p1a2t1+p1a2t2+p1a2t3)"0

   (0=!.0])@((2^_31)&gXtsz@:p1a2) gXsteps _11.62 11.62 21
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
NB. ... script Signature1.ijs (continued) ...

NB. ... verbs ...
NB. ... Bessel function of order 2 and derivatives ...

bSj2D0=:((2;0;(2^_44)"_)bSbssl])`0:@.(0=!.0])"0
bSj2D1=:((2;1;(2^_44)"_)bSbssl])`0:@.(0=!.0])"0
bSj2D2=:((2;2;(2^_44)"_)bSbssl])`2:@.(0=!.0])"0
bSj2D3=:((2;3;(2^_44)"_)bSbssl])`0:@.(0=!.0])"0
bSj2D4=:((2;4;(2^_44)"_)bSbssl])`0:@.(0=!.0])"0

graphic02.jpg

... coordinates ...



\begin{gather*}
\intertext
{\texttt
{... $x$ from $v$ ...
}
}
\begin{align*}
\begin{split}
x^1
=
&
v^1
\cos v^2    \\
x^2
=
&
v^1
\sin v^2
\end{split}    \\
\intertext
{\texttt
{... $y$ from $x$ ...
}
}
\begin{split}
y^1
=
&
x^1
+
o1    \\
y^2
=
&
x^2
+
o2
\end{split}    \\
\intertext
{\texttt
{... $q$ from $y$ ...
}
}
\begin{split}
q^1
=
&
\sqrt
{
(y^1)^2
+
(y^2)^2
}    \\
q^2
=
&
\arctan
{
\frac{y^2}{y^1}
}
\end{split}    \\
\end{align*}
\intertext
{\texttt
{...
}
}
\begin{split}
t
=
&
a_0
J2D0(b_0q^1)
\cos(2q^2)
\end{split}    \\
\intertext
{\texttt
{...
}
}
\begin{split}
t
=
&
a_0
J2D0
\biggl(
b_0
q^1
\Bigl(
y^i
\bigl(
x^i(v^1,v^2)
\bigr)
\Bigr)
\biggr)
\cos
\biggl(
2
q^2
\Bigl(
y^i
\bigl(
x^i(v^1,v^2)
\bigr)
\Bigr)
\biggr)
\end{split}    \\
\end{gather*}

NB. ... script Signature1.ijs (continued) ...

NB. ... coordinates ...

cv1=:0{]
cv2=:1{]

cx1=:0{]
cx2=:1{]

cy1=:0{]
cy2=:1{]

cq1=:0{]
cq2=:1{]

NB. ... verbs ...

x1=:(cv1*cos@cv2)"1
x2=:(cv1*sin@cv2)"1
xc=:(x1,x2)"1

y1=:(cx1+gXo1)"1
y2=:(cx2+gXo2)"1
yc=:(y1,y2)"1

q1=:((*:@cy1+*:@cy2)^0.5"_)"1
q2=:arctan@(cy1,cy2)"1
qc=:(q1,q2)"1

t=:(gXa0*bSj2D0@(gXb0*cq1)*cos@(2*cq2))"1

vGen=:(0{])(,"0"0 1&gXsteps)1{]

xcC=:xc`(''"_)@.($@]-:1$0:)
ycC=:([(yc)xc)`(''"_)@.($@]-:1$0:)
qcC=:([qc[(yc)xc)`(''"_)@.($@]-:1$0:)
NB. ... execute (ijx) ...

   p1b1=:gXts0@xcC-:gXts0@([((cy1-gXo1),cy2-gXo2)"1[((cq1*cos@cq2),cq1*sin@cq2)"1 qcC)
   (0.25;0.25;2;11.62) p1b1 vGen 0 0.646447 30,:0 2p1 100
1
NB. ... plot (ijs) ...

load 'plot'
pd 'viewpoint 3 3 1'
pd 'viewsize 1 1 0.1'
pd (0.25;0.25;2;11.62) (x1;x2;[t qcC) vGen 0 0.646447 30,:0 2p1 100
pd 'pdf'
pd 'show'

graphic03.jpg

... a surface ...

last edited 2008-07-07 05:53:00 by TomAllen