IBM Release 1.93 manual FREQ 200*THz

Models: Release 1.93

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FREQ

Syntax: FREQ <frequency in Hz>

LAMBDA

Syntax: LAMBDA <wavelength in metres>

 

Specify the frequency or free-space wavelength of the excitation

 

sources (all will be the same). FREQ is an alternative to

 

LAMBDA—use one or the other, but not both.

 

Examples:

 

 

 

FREQ 200*THz

 

 

 

FREQ c/(1.464*700*nm)

/* 700 nm in fused SiO2 */

 

LAMBDA 1.55*micron

/* Communication wavelength */

 

LAMBDA 6.328e-7

/* He-Ne laser */

 

 

 

 

 

FUNCTION

Define a user math function. User functions can be anything REXX

 

can evaluate, plus elementary functions (sin, cos, tan, asin, acos,

 

atan, atan2, exp, ln), Bessel functions of the first kind of integer

 

order (Jn(x)), complete elliptic integrals, and a few other odds and

 

ends. Once defined, a user function can be used freely in

 

expressions anywhere a literal number or a variable could.

 

Functions may be defined in terms of variables, literals, or other

 

functions, subject to the file parsing rules. When optimization is

 

enabled, functions whose output values depend on variables being

 

optimized over will have their definitions updated on each iteration

 

to reflect the new values of these variables.

 

If the name of a formal parameter of the function is the same as

 

that of a user variable, the formal parameter will override the user

 

variable inside the function. Otherwise, any variables used by the

 

function will be taken from the global scope. This allows functions

 

to be parameterized by other variables, e.g. scale factors or offsets,

 

which are not in the formal parameter list.

 

Syntax:

 

 

 

FUNCTION name(arg1, arg2,..., argN) = <expression>

 

Examples:

 

 

 

FUNCTION myfunc(a,x,q)=exp(a)*atan(q/x)*sqrt(23+q)

 

FUNCTION parab(x,y,focus)=(x*x+y*y)/(4*focus)

 

FUNCTION cone(x,y)=sqrt(parab(x,y,1)

 

 

 

 

HOSTS

Specifies a file containing TCP/IP information on the hosts available

to run the current simulation. Syntax: HOSTS <hostfile>

where entries in the given file are of the form

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IBM Release 1.93 manual FREQ 200*THz