TRACE

Trace in VC

This macro only appears in the DEBUG version of the program. When RELEASE, the macro disappears completely, which helps you debug and reduce the amount of code when RELEASE.

Very simple to use, the format is as follows: TRACE("DDDDDDDDDDD"); TRACE("wewe%d",333); TRACE0, TRACE1, TRACE2 also exist. . . Corresponding to 0, 1, 2, respectively. . The parameter TRACE information is output to the output window of the VC IDE environment (this window is the window where you are prompted to compile the project error), but only if you run your DEBUG version of the program in VC.

TRACE information can also be captured using DEBUGVIEW. In this case, you cannot run your program in the IDE environment of VC, but run the DEBUG version of the program with good BUILD alone. At this time, you can see the output in the DEBUGVIEw format in the DEBUGVIEW window.

There are four usages of TRACE in VC:

1: TRACE, that is, the output string without dynamic parameters, similar to C's printf ("output string");

2: The string in TRACE can be output with a parameter, similar to C's printf (".%d", variable);

3: TRACE can take two parameters to output, similar to C's printf(".%d.%f", variable 1, variable 2);

4: TRACE can be output with three parameters, similar to C's printf (".%d, %d, %d", variable 1, variable 2, variable 3);

The TRACE macro is a bit like the Printf function we used in the C language before, so that the program outputs some debugging information during the process, so that we can understand some status of the program. But there is one difference: the TRACE macro is only output in the debugging state, and the Printf function used before has output in any case.

Like the Printf function, the TRACE function can accept multiple parameters such as: int x = 1; int y = 16; float z = 32.0; TRACE( "This is a TRACE statement\n" ); TRACE( "The value of x is %d\n", x ); TRACE( "x = %d and y = %d\n", x, y ); TRACE( "x = %d and y = %x and z = %f\n" , x, y, z ); It should be noted that the TRACE macro only affects the Debug version of the project. In the Release version of the project, the TRACE macro will be ignored.

MATLAB functions

Function introduction

Function function: In FreeMat and Matlab, this function is used to find the trace of the two-dimensional square matrix, that is, the sum of the elements on the diagonal of the square matrix.

Syntax format:

y = trace(x)

Here x is a square matrix.

Algorithm implementation of trace function: t = sum(diag(A));

Related functions: det, diag

Program example

--> A = [1 2 3; 4 5 6; 7 8 9];

--> trace(A)

ans = 15

--> B = [1 0 0; 0 1 0; 0 0 1];

--> trace(B)

ans = 3

--> sum(diag(A))

ans = 15

--> sum(diag(B))

ans = 3

Debugging information display function in Flex

trace(.):void

Used for output in debug mode, similar to System.out.println() in java;

1. Run the program in debug mode;

2. Click on the console;

3. Run the program block with trace() function, the console will output debugging information;

API introduction:

Display expressions or write log files during debugging. A single trace statement can support multiple parameters. If any parameter in the trace statement contains a data type other than String, the trace function will call the toString() method associated with that data type. For example, if the parameter is a Boolean value, the tracking function will call Boolean.toString() and display the return value.

parameter:

arguments One or more (comma separated) expressions to be evaluated. For multiple expressions, a space is inserted between each expression in the output.

language version:

3.0

Player version:

Flash 9, AIR 1.0, Lite 4