ALADDIN Language Format and Data Types

[ Command Language Format ] [ Data Types ]


COMMAND LANGUAGE FORMAT

The ALADDIN command language corresponds to individual statements, and sequences of statements.

     statement 1;    
     statement 2;    
     ........
     statement N;

Each statement ends with a semi-colon (;).

Comment Statements

As with C, comment statements are enclosed between /* .... */ , as in

    /*
     *  =========================================================
     *  Here is a comment that introduces a block of N statements
     *  =========================================================
     */

     statement 1;         /* the  first ALADDIN statement */
     statement 2;         /* the second ALADDIN statement */
     ........
     statement N;         /* the   n^th ALADDIN statement */

Last Statement : The last statement in an ALADDIN session should be

    quit;


DATA TYPES

ALADDIN support three data types, character strings, physical quantities, and matrices of physical quantities. Here are some examples of each type:

Character Strings

A character string is simply a sequence of characters enclosed between quotes. To print the character string

     "My First Character String"
just type something like
     print "My First Character String\n";
The end-of-line character (\n) forces output onto a new line.

Physical Quantities

A physical quantity is a number plus a set of physical units. For example, the script

     2 cm/sec;
defines a velocity of two centimeters-per-second. In ALADDIN, numbers are simply physical quantities without dimensions.

Matrices

In ALADDIN a matrix is a rectangular array of physical quantities. For example, the statement

    A = [ 1, 2, 3;
          4, 5, 6 ];
defines a (2x3) array of numbers. The script
Spectra = [ 0.0 sec,  10.0 cm/sec/sec;
            0.1 sec,  12.3 cm/sec/sec;
            0.2 sec,  12.3 cm/sec/sec;
            0.4 sec,   5.0 cm/sec/sec ];
defines a (4x2) array of physical quantities. Entries in the first and second columns have units of time and acceleration, respectively. The command
PrintMatrix ( Spectra );
generates the output
MATRIX : "Spectra"

row/col                  1            2   
        units          sec      m/sec^2   
   1            0.00000e+00  1.00000e-01
   2            1.00000e-01  1.23000e-01
   3            2.00000e-01  1.23000e-01
   4            4.00000e-01  5.00000e-02


Developed in April 1996 by Mark Austin
Last Modified June 20, 1996
Copyright © 1996, Mark Austin, Department of Civil Engineering, University of Maryland