Viewing Variable's memory location content?

Hi,

I would like to ask a question on variable display.

In C/C++, during debugging one can view variables directly at their memory location, and in most IDEs could you could choose display option (decimal, hex, binary, etc.).

Is it possible view variables like this in Matlab?

Does Matlab allow memory access? A little deeper: if Matlab is written in Java, does JVM, during bytecode execution, allow viewing memory location contents of variables?

Bob

Answer 1

[Jan]

Matlab is not written in Java.

You can display the memory location of arrays by:

format debug

In addtion you can call a C-Mex file, which allows full access of the underlying data structure. But this structure is not documented and subject to changes. You can look in the FEX submissions of James Tursa to learn more about this: FEX: Author James Tursa

[Bob Li]

http://en.wikipedia.org/wiki/MATLAB

The 1st able on the right: Written in C,Java

Picking up the Pace with the MATLAB Profiler

http://www.mathworks.cn/company/newsletters/news_notes/may03/profiler.html

Is it a mixture? How much part in C and how much in Java?

[Jan]

The computations are done in C. The GUI is based on Java, e.g. all visible GUI-elements are modified Java-Objects.

But you can run Matlab without Java, if you do not create GUI outputs. In addition, most toolbox functions of Matlab are written in Matlab. Before we discuss the relation of Java versus C code, the term "Matlab" must be defined clearly.

I think, this discussion is very accademic. Do you have a specific problem?

[Bob Li]

Jan,

Just interested:)

"most toolbox functions of Matlab are written in Matlab."

You mean toolbox functions are built on top of basic Matlab functions? It is quite clear if one opens some .m file of functions.

So I guess some very basic structures and their associated operations are written in C, and then uses Matlab commands to build the toolbox hierarchically?

[Jan]

@Bob: Correct. The memory management, mxArray structs, indexing, +-*/ is implemented in C. Linear algebra calls BLAS (I assume the FORTRAN version) or MKL (Assembler), and MEAN is an M-file.

[Bob Li]

Jan,

Do you know how to enable email notification for answer's comments? I never got a single notification for comments, and it seems there is no things like "configuration/options" in account setting to enable this?