eval: command line calculator Files

Eval: command line and console calculator.

File Eval_Code.zip contains source code for the program.
eval.zip contains binary for windows.
concalc.tar.gz contains binary for Linux.

Building from sources.

The program is written in Free Pascal and can be built either with Lazarus or 
with a Free Pascal text.mode IDE. It uses LMath library and CRTExt unit from 
NVUtils package.

Sources of these libraries are included together with the sourse of
eval. To build the program from sourse, first compile these packages,
then the program itself.

Installing

Windows.
Unpack and copy eval.exe and eval.txt to a location of your preference.

Linux.
Linux version is called concalc to avoid name conflict with built-in eval
command. Correspondingly, in all examples below, in Linux write concalc 
instead of eval.
 
Usage

I. Command line

Command line parameter(s) are interpreted as a mathematical expression. 
All spaces are ignored. The expression is evaluated, result is printed in 
the console and the program terminates.

Example 1:
c:\>eval sin(3.14159/2) + 1
    1.0000

If no command line parameter is present, interactive session is started and 
prompt ">" is displayed.

II. Interactive session

Enter an expression to evaluate. Result of evaluation will be 
printed out and automatically assigned to "_LAST" variable which may be used 
in further calculations.

Example 2:
c:\>eval
Console calculator. Enter expression to evaluate.
Type "help" or "?" to get help; type "exit" or "q" to exit.
> exp(4.5)
   90.0171
> x/2
   45.0086
> _last
   45.0086
   
Alternatively, you can explicitly assign the result of evaluation to another 
variable using ":=" operator. 

Variable names can consist of latin letters "A"-"Z", "a"-"z", numbers and 
symbol "_". 
Variable name cannot begin with a number. It is not recommended to use 
names beginning with "_". They are reserved for internal use. 
Names are case-insensitive.

Example 3:
> MyVar := 25
   25.0000
> a := 30
   30.0000
> a+MyVar
   55.0000
   
Assign value to _DECIMAL variable to change number of digits after the decimal 
dot. The setting will be preserved for future sessions and command line use.

Example 4:
>_decimal
4.0000
>2+3
5.0000
>_decimal := 6
6.0000
>2+3
5.000000

Type "help" or "?" to get help in a session. Type "q" or "exit" to terminate.

III.Mathematical operators and functions

Operators: +, -, *, /, \ (integer division),% (modulus), ^, ** (exponentiation).
Bitwise: > shift right, < shift left, & and,| or, $ xor, ! not, @ imp, = EQV.

Precedence: !, &, |, $, =, @, ^, * and /, \, %, < and >, + and - .
Parenthesis may be used to override the precedence.');

Following functions are defined (names are case-insensitive). 

Elementary functions: 
abs(X), Sgn(X), Int(X), Sqrt(X), Exp(X), Ln(X), Log10(X),
Log2(X), Fact(N), Binomial(N,K), Rnd().

Trigonometric functions:
Deg(X), Rad(X), Sin(X), Cos(X), Tan(X),
ArcSin(X), ArcCos(X), ArcTan(X), ArcTan2(X,Y).

Hyperbolic trigonometric functios:
Sinh(X), Cosh(X), Tanh(X), ArcSinh(X), ArcCosh(X), ArcTanh(X).

Special functions:
Gamma(X), IGamma(X), Beta(X,Y), IBeta(A,B,X), Erf(X), LambertW(X)

Probability functions:
PBinom(N,P,K), FBinom(N,P,K), PPoisson(Mu,K), FPoisson(Mu,K), 
DExpo(A,X), FExpo(A,X),
DGamma(A,B,X), FGamma(A,B,X), DBeta(A,B,X), FBeta(A,B,X),
DNorm(X), FNorm(X), PNorm(X), InvNorm(X), 
DStudent(N,X), FStudent(F,X), PStudent(N,X), InvStudent(N,P), 
DKhi2(N,X), FKhi2(N,X), PKhi2(N,X), InvKhi2(N,P)
DSnedecor(N1,N2,X), FSnedekor(N1,N2,X), 
PSnedecor(N1,N2,X), InvSnedecor(N1,N2,P)

Examples 5 - 7:
4 * arctan(1)  -->  3.1416
sin(0.5)^2 + cos(0.5)^2    -->  1.0000
sinh(0.5)^2 - cosh(0.5)^2 --> -1.0000