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This software is provided AS IS with NO WARRANTY.

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Hi Fortran Programmers

OK, the function interpreter is now finished (at least to a level that
satisfies me).

PLEASE, this code comes AS IS without any warranty of any kind.  I have
developed this code enough to satisfy my own needs and no body elses. 
If you find a use for it, well and good.  If you manage to improve on
it, please me know and I will put the improvements in my own code.

The interpreter does 61 functions 

    cos(x)
    sin(x)
    tan(x)
    exp(x)
    log(x)
    log10(x)
    logn(x,y)
    sqrt(x)
    cbrt(x)
    acos(x)
    asin(x)
    atan(x)
    cosh(x)
    sinh(x)
    tanh(x)
    anint(x)
    aint(x)
    abs(x)
    delta(x)
    step(x)
    hat(x)
    min(x,y)
    max(x,y)
    besj0(x)
    besj1(x)
    besjn(n,x)
    besy0(x)
    besy1(x)
    besyn(n,x)
    besi0(x)
    besi1(x)
    besin(n,x)
    besk0(x)
    besk1(x)
    beskn(n,x)
    erf(x)
    erfc(x)
    ierf(x)
    ierfc(x)
    gamma(x)
    lgamma(x)
    csch(x)
    sech(x)
    coth(x)
    if(conditional, true, false)
    gauss(x)
    sinc(x)
    fresc(x)
    fress(x)
    expi(x)
    sini(x)
    cosi(x)
    logi(x)
    elle(x)
    ellk(x)
    ielle(x, phi)
    iellf(x, phi)
    modulo(x,y)
    mod(x,y)
    floor(x)
    ceiling(y)

16 operators

    +
    -
    *
    /
    //		Integer Divide
    %		Integer modulo
    **
    ^
    >
    >=
    =>
    <
    <=
    =<
    ==
    =
    !=

brackets and correct order of operation.

Numbers are all assumed to be double precision real and are entered in
the usual fortran double precision way (or any way that read(*,*) num
will interpret)

# = integer

	#
	.#
	#.#
	#.#d#
	#.#d-#
	#.#d+#
	#.#e#
	#.#e-#
	#.#e+#
	#.#D#
	#.#D-#
	#.#D+#
	#.#E#
	#.#E-#
	#.#E+#

etc...

The functions are simply strings with any number of possible variables



****  THE CODE NOW HAS ERROR DETECTION  ****

Yes, I got around to adding it at the request of a user of my code.
Basically, the code will try to detect when an illegal function is
entered.  It is quite basic, but seems to work quite well.

Basically, when calling the function, you have the option of
including an error field ( character(len=#)::error ).  If no error
occurs, this error field will contain OK.  If an error is detected
then error will contain the first # chacters of the error explanation.

It will still return a valid number (that obtained previously) but you
can at least have some primitive idea of what went wrong.

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****  THE CODE NOW DOES ERROR LIMIT COMPUTATIONS  ****

The code now allows the computation of error calculations of the form

	D = delta (error)
	d = partial derivative

	Df = df/dx Dx + df/dy Dy

You input the variables using a square bracket

	x[0.1]

would give an error of 0.1 on the variable x.

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Anyway, the code isn't documented, though it should be really easy to
follow.



KNOWN PROBLEMS

No known problems.


If you have any problems, let me know.

Stu.