Getting started
After downloading the file timedepFlowVis.tar.gz
you should unpack this file to some directory using the commands
gzip -d timedepflowVis.tar.gz
tar -xvf timedepflowVis.tar
This will extract all files you need. Next
you should compile the package using the given Makefile (command
"make").
The compile process will create a sample program which will visualize the
sample vector field data contained in the directory benard. Start the program
using the command "main".
The program will start and write a lot of
messages about what it is doing onto the screen. The gray-level output images will
be placed in the directory picture/ and the colored images will be saved in the
directory colored_picture/. The directories have been created when unpacking
the tar-file. You can use any image viewer, that can read PGM files, e.g.
xv, to view the images.
The default vector field example is called "EXAMPLE_BENARD".
The C++ source code enclose two other examples: "EXAMPLE_WHIRLPOOL"
and "EXAMPLE_CIRCLE".
If you want to create another vector field example you have to modify the source
code. The examples are defined in the main program (confer "timedepflowvis.cpp"):
int main() {
#define EXAMPLE_BENARD
//#define EXAMPLE_CIRCLE
//#define EXAMPLE_WHIRLPOOL
TransportDiffusion
*diff;
//... omitted source code
#ifdef EXAMPLE_CIRCLE
diff = new TransportDiffusion(10,400,400,0.01,
"./picture/picture%03d.pgm","./color_picture/color_picture%03d.pgm",
1./1000.,1./100.,200.,0.4,200,1.e-6,
lowColor,highColor);
#endif
#ifdef EXAMPLE_WHIRLPOOL
//...omitted source code
diff= new
TransportDiffusion(vf,T,M_width,N_height,0.01,
"./picture/whirlpool_%03d.pgm","./color_picture/color_whirlpool_%03d.pgm",
1./1000., 1./10000.,
100.0, 0.5, 500, 1.e-6,lowColor,highColor);
#endif
#ifdef EXAMPLE_BENARD
diff = new
TransportDiffusion("./benard/benard_%d.dat",10, 0.1,
"./picture/029_benard_%03d.pgm",
"./color_picture/029_color_benard_%03d.pgm",
1./100., 1./100.,
1.0, 0.4, 500, 1.e-6,lowColor,highColor);
#endif
diff->timeStep(1,9);
delete
diff;
//... omitted source code
}
As seen below you only have
to change the red lines. For example, if you like
to have the circle vector field, you have to define "EXAMPLE_CIRCLE"
and to undefine the other examples:
//#define EXAMPLE_BENARD
#define EXAMPLE_CIRCLE
//#define EXAMPLE_WHIRLPOOL
The file
FlowVisSourceCode.tar.gz contains only
the C++ source code and not the vector field data. That means that you have only
the choice between EXAMPLE_CIRCLE and EXAMPLE_WHIRLPOOL.
Available Constructors and the Function "TimeStep"
The file timedepFlowVis.cpp implements three constructors and the function
"TimeStep" computing the nonlinear anisotropic transport diffusion to visualize a vector field given in an
(M_width x N_height) array.
As seen below, the main program creates an object (e.g. diff)
using one of the three different constructors.
Each example uses another constructor.
Available constructors are:
Transport_Diffusion(char*
VFfileName, int T ,
D_TYPE tau,
char* outputFile, char* colorOutputFile,
D_TYPE lambda,
D_TYPE lambda2,
D_TYPE beta, D_TYPE scaleF,
int MAXCOUNTER, D_TYPE eps
int* lowColor, int* highColor
);
Transport_Diffusion(d3p* vf, int T,
int M_width, int N_height,
D_TYPE tau,
char* outputFile, char*
colorOutputFile,
D_TYPE lambda,
D_TYPE lambda2,
D_TYPE beta, D_TYPE scaleF,
int
MAXCOUNTER, D_TYPE eps
int* lowColor, int* highColor
);
Transport_Diffusion(int T, int M_width,
int N_height,
D_TYPE tau,
char* outputFile, char* colorOutputFile,
D_TYPE lambda,
D_TYPE lambda2,
D_TYPE beta, D_TYPE scaleF,
int MAXCOUNTER, D_TYPE eps
int* lowColor, int* highColor
);
The call of the function "timeStep" ( e. g.
diff->timeStep(1,50); ) will produce several images.
It solves some time steps of the PDE system. The first time step will be the one
with number "first", the last time step will be the one with number
"last".
Function returns 0 if it was executed successfully and some value different from 0
else.
int timeStep(int first, int last);
The Variables
As seen in the previous section you can set
many parameters for the transport diffusion process by using a constructor from
above. The following table
tells you the meaning of the parameters which have to been set. The values
below the type definitions of a parameter give the default value that will be
set by the constructor if this parameter is omitted.
This site contains the C++ source code and the documentation for routines
incorporating the anisotropic nonlinear transport diffusion for time dependent flow visualization.
The gzipped tar file contains the header file "timedepFlowVis.h",
the source file "timedepFlowVis.cpp", a Makefile, a
sample program, and this html file.
