C Shell Programming

http://heather.cs.ucdavis.edu/~matloff/UnixAndC/Unix/CShellII.html
http://www-cs.canisius.edu/ONLINESTUFF/UNIX/shellprogramming.html

[Matlab] Create a figure with specified location and size

Source

Matlab Help, figure

Syntax

rect = [left bottom width height];
% The unit of rect is pixel by default.
% left = the distance between the left of the figure and the left of the screen
% bottom = the distnace between the bottom of the figure and the bottom of the screen
figure( 'Position', rect );

Code

[Matlab] Specify a figure to plot

Source

Matlab Help

Syntax

set(0,'CurrentFigure',figure_handle);

Code

h1 = figure;
h2 = figure;
set(0,'CurrentFigure',h1);
plot( x1, y1 );
set(0,'CurrentFigure',h2);
plot( x2, y2 );

[CPP] Conversion from char** to const char** Not Allowed

Source

http://coding.derkeiler.com/Archive/C_CPP/comp.lang.cpp/2004-10/1514.html

Description

If the conversion from char** to const char ** is allowed, then user may write a sequence of assignments which modifies a constant. Following is an exsample from Gianni Mariani posted at coding.derkeiler.com

const char * A[2] = { "A", "B" };
char * B[2];

int main() {

char ** b = B;
const char ** a = b; // illegal
//const char ** a = ( const char ** ) b; // BAD work-around (1)
//const char * const * a = b; // better option (2)
a[0] = A[0]; // illegal if you use (2) ok if you use (1)
b[0][0] = 'X'; // const violation - big probs if you use (1)

}

[Unix] Frequently Used Commands

grep

grep foo file

print the lines containing the pattern foo in file

ls | grep foo

print the lines from STDIN containing the pattern foo

grep -r -e 'PATTERN' ./user *.txt

Find a pattern PATTERN in all txt files, recursively search for all sub directories of directory "./user"

xrdb

xrdb RESOURCE_FILE

Load the resource file for X windows (e.g. xterm). The default resource file is ".Xdefaults"

top

top

Check the computer resource usage.

ln

ln -s

Check the computer resource usage.

find

find . -name "abcd*"

Find a file with "abcd" as part of the filename in current directory or the sub directories

[Matlab] Use Plain Text in labels and legends

Source

Matlab Help. Search for keyword 'interpreter'.

Description

To print the labels and the legends in plain text such that `_' and `^' will not be transcribed to subscript and superscript specifier.

Syntax

% Interpreter_type: 'latex' | {'tex'} | 'none'
set(handle, 'Interpreter', Interpreter_type );

Code

h_label = xlabel('MY_LABEL');
set(h_label, 'Interpreter', 'none');

h_legend = legend('LEG_1', 'LEG_2');
set(h_legend, 'Interpreter', 'none');

[Matlab][Debug]mxDestroyArray

Source

Matlab Help: Memory Management Compatibility Issues

Syndrome

The matlab engine properly opens and closes at the first time. But at the second attempt of starting matlab engine the error message pops up:

Forced Assertion: "Corrupted memory block found"

Cause

• mxDestroyArray was called on a mxArray whose data was not assigned by matlab API

  mxArray *temp = mxCreateDoubleMatrix(1,5,mxREAL);
  double data[5] = {1,2,3,4,5};
  ...
  memcpy(mxGetPr(temp), data, 5*sizeof(double));
  ...
  mxDestroyArray(temp); // <-- INCORRECT. Do NOT call mxDestroyArray on temp

Solution

• Do NOT call mxDestroyArray on such mxArray's

C++ and C FAQ

Source

Comeau C++ and C FAQ

Embedded System Design

C++ FAQ LITE

Description

You can probably find answers to the fundamental questions about c++ programming.

Memo

• Constant objects can be declared with various types and user can access the address of the constant objects.
• Enumeration Constants can only be integers and the address of enumeration constant is not available. But it also means that compilers won't generate codes for the ability to take the address, which becomes an advantage of using enumeration constants if users do not need the address of the constant.
• When writing class template, the definition and the declaration should "be seen by compiler at the same time," which means one may 1. write both the declaration and the implementation in the same file (the .h file); 2. include the implementation file (.cpp) in the header file (.h), not include the header file in the implmenetation file. To explain this in one sentence: A class template is not a real class and the compiler will not see the functions of the class template with specified type.

[LINUX] Bash Programming

Source

BASH Programming - Introduction HOW-TO by Mike G
Advanced Bash-Scripting Guide by Mendel Cooper
Bourne Shell Programming

[LINUX] If The Script Does Not Run

Check:

• Is the script saved in Linux/Unix format (If saved in DOS format you may see "Command not found" error message). The command to remove the '\r' from DOS format is

  $ tr -d '\r' < DOS_file > UNIX_file

  The '<' is to input the DOS_file to command 'tr' and '>' is to output the file without '\r'. The commands including UNIX-to-DOS conversion can be found here
• Is the script executable (if not you may see "Permission denied" error message

[Software] PSPad Issues

PSPad changes the unix permission when editing files

Forum discussion: http://forum.pspad.com/read.php?2,18205,18205#msg-18205
Solution:

Program settings --> Direct edit
[x]DontChangeFileAttribs=1

[Perl] Regular Expression With Chinese Char

Use \Q中文字\E

Windows Batch Commands

Source

http://www.computerhope.com/batch.htm

Run .bat file in a .bat file

Codes:

call bat1.bat
call bat2.bat

[Matlab] Plot lines with different markers

Source

Matlab Help:

• Find "LineSpec" to see the available markers

Codes

% Initialize a set of desired markers
MarkerSet = 'x*o+s.^v';
plot( x, y ); grid on;
% Obtain all line handles under current axes handle
hdl = findobj(gca,'Type','line');
for k=1:length(hdl)

% Assign markers to each line handle
set(hdl(k), 'marker', MarkerSet(k) );

end

[Matlab] Plotyy and the Labeling

Source:

Matlab Help

Codes:

MY_XLABEL = 'This is xlabel';
MY_Y1LABEL = 'This is y1 label';
MY_Y2LABEL = 'This is y2 label';
MY_Y1LEGEND = {'y1_lg1', 'y1_lg2' };
MY_Y2LEGEND = {'y2_lg1', 'y2_lg2' };
MY_TITLE = 'This is my title';

[AX,H1,H2] = plotyy(x1, y1, x2, y2);
xlabel( MY_XLABEL );
set(get(AX(1),'Ylabel'),'String', MY_Y1LABEL );
set(get(AX(2),'Ylabel'),'String', MY_Y2LABEL );
legend(H1, MY_Y1LEGEND, 'Location', 'NorthWest' );
legend(H2, MY_Y2LEGEND, 'Location', 'NorthEast' );
title( MY_TITLE );

[HTML] Symbol Reference

Greek, mathematical, symbolic characters, and so on.
http://everything2.com/index.pl?node=HTML%20symbol%20reference

[Matlab] Data Clipping, saturation

% 'x > upperbound' evaluates to a logical index
x = array to be clipped;
x( x > upperbound ) = upperbound;
x( x < lowerbound ) = lowerbound;

Quotes

"There is only one thing more beautiful than one guitar - Two guitars" Frederic Chopin

[EE] Forum and Sites

DSP related:
http://www.dsprelated.com/

[Math] Statistics Online Resources

http://davidmlane.com/hyperstat/index.html