Overview of the interpreter

Mx?
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A programming language for
scientific computation.
Related Languages:
Matlab
IDL
Maple, Mathcad, Mathematica
Goals
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Portability - interpreted and executed by
a java interpreter.
Efficiency - greatly improves
programming efficiency. Program
involving many matrix and vector
operations are very short in Mx.
Ease of use - very simple and quick to
start
What can the language do?
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Basic matrix operations –
addition, multiplication…
Advanced operations – matrix slicing
and masking.
Internal functions – Print, input,
load, save, plot, paint
Operations and Relations
Arithmetic Operations *, /, %, /’, ‘, +, -
Logical Operations
not and or
Relational Operations >, >=, <, <=, ==,
!=
Array and Range
Range Specifier
:
i.e.. A[1:10, 1:2]
::
i.e.. A[1::2]
Array Constructor
[1,2;3,4]
Statements
Block Statement
{}
iteration
for (n = 1:100);
loop
=
if (exp) <stat>;
if (exp) <stat> else
<stat>
break;
continue;
Assignments
Conditional Statements
Break and Continue
Functions and Function call
Self Defined
Functions
func <id> (para-list)
= exp;
func <id> (paralist){}
Function Call
id(para-list);
Note: can either be
stand-lone or right
value depends on if it
has returned value
Internal functions
•Console output
print() print arguments to the standard output one by one.
•Picture drawing
paint() draws a matrix in a new window as an image
plot() takes a matrix and plots it as a graph
•Color
color() sets the current color (in RGB)
colormap() take a matrix with rows as RGB, and sets a colormap.
•File I/O functions
load( file, type, m, n )
save( matrix, file, type )
•Matrix generator
zeros( m, n )
random( m, n )
•matrix operator
inv( matrix )
flip( matrix )
Example 1:
Mr. Potato
A = load( "potato.dat", "byte", 128,128 );
colormap(1);
paint( [ A, flip(A), mirror(A), flip(mirror(A));
A', flip(A'), mirror(A'), flip(mirror(A'))] );
return 0;
Overview of the interpreter
Currently the Mx programming language is implemented
interpretively.

The interpreter parses and executes the user input or
programs in files, and generates printed output and/or
pictures.

The parser of the interpreter is written in Antlr, and the rest
routines are in Java.

For a small portion of our code, we tried macro expansion
in Java.

Adequate functionalities made our project quite large,
luckily most of the functions are tested and work well
(maybe we have forgotten the existences of some
functions?)

Code Statistics
Parts
Frontend
Statistics 481
(lines)
Total
Interpret Matrix
er
class
test code
2090
941
2731
5891 lines (generated code not
included)
(partial, currently in CVS)
Why another matrix class?
•The Mx programming language has important
functionalities: in-place matrix slicing and masking
•Existing Java matrix classes do not support these
What can we do in Mx with slicing
and masking?
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A = zeros(256,256);

A[10:40,:] = 1;
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A[25::50,60::50] = random(50,50);
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A[A>=0.75 or A<=0.25] = 0.5;
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A[100:199,100:199] = random(100,100)
+ A[0::100,0::100]*A[0::100, 100::100] ;
An example of masking: paint
selected entries
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A = load( "mri-anat.sdt", "short", 256, 256 );
B = load( "mri-func.fdt", "float", 256, 256 );
A = flip(A');
B = flip(B');
paint( A );
colormap(4);
opaint( B, B>0.7, 0, 0, 0.7, 1.0 );
The features of our matrix class
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Arithmetic operations: + - * / ...
Sharing data between matrices
Matrix slicing and masking
Inversion and solving linear equations
Comparing matrices
Painting and plotting
Transpose, flipping and mirroring
And more...
The type system
Testing Plan
• 3 Stages:
• Unit Testing
 Creation of our own library using Matlab as
guidance.
 Library contains its own unit testing program.
• Regressive Testing
 Creation of a script to automate regressive testing
written in tcl
 Takes a database of one or more *.mx programs
 See example
Example of the Testing Database
;;; samples.tdb: a sample of testing
;;; database for the Mx
;; assign
1 2 3 4 { a = [1,2;3.4]; return a; }
;; transpose
1 3 2 4 { a = [1.2;3,4]’ ; return a;}
;; transpose transpose
1 2 3 4 { a = [1,2;3,4]’’ ; return a;}
;; triple transposes
1 2 4 { return [1;2;4]’’’ ; }
;; matrix add
1 2 3 4 { return [1,1;1,1] + [0,1;2,3]; }
Testing Plan
• Advanced Testing
 Necessity for larger testing programs

Integrated all the examples from the
tutorial and used them as our
advanced testing examples.
Lessons Learned
1. Fully investigate the feasibility of the
supporting tools
 Original Matrix classes lacked many
functions
 Plotting, painting, masking, etc.
2. Get advice from experienced
3. When an easier method of implementing
classes of function exists, use it

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