libplplot-dev 5.10.0+dfsg2-0.1ubuntu2 / usr / share / doc / libplplot12 / examples / c++ / x01cc.cc

//--------------------------------------------------------------------------
// $Id: x01cc.cc 11297 2010-11-02 03:31:14Z airwin $
//--------------------------------------------------------------------------
//
//--------------------------------------------------------------------------
// Copyright (C) 1994 Geoffrey Furnish
// Copyright (C) 1995, 2000 Maurice LeBrun
// Copyright (C) 2002, 2002, 2003, 2004 Alan W. Irwin
// Copyright (C) 2004  Andrew Ross
//
// This file is part of PLplot.
//
// PLplot is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; version 2 of the License.
//
// PLplot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with PLplot; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
//--------------------------------------------------------------------------
//
//--------------------------------------------------------------------------
// This example program demonstrates the use of the plstream C++ class, and
// some aspects of its improvements over the klunky C API, mostly those
// relating to 2-d plotting.
//--------------------------------------------------------------------------

#include "plc++demos.h"

#ifdef PL_USE_NAMESPACE
using namespace std;
#endif

//--------------------------------------------------------------------------
// In the real world, the user has his own Matrix class, so he just includes
// the header for it.  Here we conjure up a dopey stand in.

class Matrix {
    int   nx, ny;
    PLFLT *v;
public:
    Matrix( int _nx, int _ny ) : nx( _nx ), ny( _ny ) { v = new PLFLT[nx * ny]; }
    ~Matrix() { delete[] v; }

    PLFLT & operator()( int i, int j )
    {
        // Should do bounds checking, pass for now.
        return v[ j * ny + i ];
    }

    PLFLT operator()( int i, int j ) const
    {
        // Should do bounds checking, pass for now.
        return v[ j * ny + i ];
    }

    void redim( int i, int j )
    {
        delete[] v;
        nx = i, ny = j;
        v  = new PLFLT[nx * ny];
    }
};

//--------------------------------------------------------------------------
// To perform contouring, we have to concretize the abstract contouring
// interface.  Do this by deriving from Contourable_Data, and implementing
// the indexing operator.

class ContourableMatrix : public Contourable_Data {
    int    nx, ny;
    Matrix m;
    int    wrapy;               // periodic in 2nd coord ?
public:
    ContourableMatrix( int _nx, int _ny, int wy = 0 )
        : Contourable_Data( _nx, _ny ),
        nx( _nx ), ny( _ny ), m( nx, ny ), wrapy( wy )
    {}
    void elements( int& _nx, int& _ny ) const
    {
        _nx = nx;
        if ( wrapy )
            _ny = ny + 1;
        else
            _ny = ny;
    }
    PLFLT & operator()( int i, int j )
    {
        if ( wrapy ) j %= ny;
        return m( i, j );
    }
    PLFLT operator()( int i, int j ) const
    {
        if ( wrapy ) j %= ny;
        return m( i, j );
    }
};

//--------------------------------------------------------------------------
// For general mesh plotting, we also need to concretize the abstract
// coordinate interface.  Do this by deriving from Coord_2d and filling in
// the blanks.

class CoordinateMatrix : public Coord_2d {
    int    nx, ny;
    Matrix m;
    int    wrapy;
public:
    CoordinateMatrix( int _nx, int _ny, int wy = 0 )
        : nx( _nx ), ny( _ny ), m( nx, ny ), wrapy( wy )
    {}

    PLFLT operator()( int ix, int iy ) const
    {
        if ( wrapy ) iy %= ny;
        return m( ix, iy );
    }

    PLFLT & operator()( int ix, int iy )
    {
        if ( wrapy ) iy %= ny;
        return m( ix, iy );
    }

    void elements( int& _nx, int& _ny )
    {
        _nx = nx;
        if ( wrapy )
            _ny = ny + 1;
        else
            _ny = ny;
    }

    void min_max( PLFLT& _min, PLFLT& _max )
    {
        _min = _max = m( 0, 0 );
        for ( int i = 0; i < nx; i++ )
            for ( int j = 0; j < ny; j++ )
            {
                if ( m( i, j ) < _min ) _min = m( i, j );
                if ( m( i, j ) > _max ) _max = m( i, j );
            }
    }
};

class x01cc {
public:
    x01cc( int, const char** );
    void plot1();
    void plot2();


private:
    plstream *pls;
};

//--------------------------------------------------------------------------
// Just a simple little routine to show simple use of the plstream object.
//--------------------------------------------------------------------------

void x01cc::plot1()
{
    pls->col( Red );
    pls->env( 0., 1., 0., 1., 0, 0 );

    pls->col( Yellow );
    pls->lab( "(x)", "(y)", "#frPLplot Example 1 - y=x#u2" );

    PLFLT x[6], y[6];
    for ( int i = 0; i < 6; i++ )
    {
        x[i] = .2 * i;
        y[i] = x[i] * x[i];
    }

    pls->col( Cyan );
    pls->poin( 6, x, y, 9 );

    pls->col( Green );
    pls->line( 6, x, y );
}

//--------------------------------------------------------------------------
// Demonstration of contouring using the C++ abstract interface which does
// not impose fascist requirements on storage order/format of user data as
// the C and Fortran API's do.
//--------------------------------------------------------------------------

void x01cc::plot2()
{
    pls->adv( 0 );

// First declare some objects to hold the data and the coordinates.  Note,
// if you don't want to go to the trouble of making these derived classes so
// easy to use (const and non-const indexing operators, etc), such as if you
// have existing code using a Matrix class, and all you want to do now is
// plot it, then you could just make these derived classes have a
// constructor taking a Matrix (previously calculated somewhere else) by
// reference through the constructor.  That way the calculation engine can
// continue to use the normal container class, and only the plotting code
// needs the auxiliary class to concretize the C++ abstract contouring
// interface.

// Since this is a "polar" plot ( :-), see below), we need to enable the
// "wrapy" option in our special purpose data and coordinate classes.  Note
// that this allows "reconnection" of lines, etc, with trivial effort, IFF
// done from C++.  For C-- and Dogtran, one would have to copy the data to a
// new buffer, and pad one side with an image copy of the other side.

    ContourableMatrix d( 64, 64, 1 );
    CoordinateMatrix  xg( 64, 64, 1 ), yg( 64, 64, 1 );

    int   i, j;
    PLFLT twopi = 2. * 3.1415927;

// Set up the data and coordinate matrices.

    for ( i = 0; i < 64; i++ )
    {
        PLFLT r = i / 64.;
        for ( j = 0; j < 64; j++ )
        {
            PLFLT theta = twopi * j / 64.;

            xg( i, j ) = r * cos( theta );
            yg( i, j ) = r * sin( theta );;
            d( i, j )  = exp( -r * r ) * cos( twopi * 2 * r ) * sin( 3 * theta );
        }
    }

// Now draw a normal shaded plot.

    PLFLT zmin   = -1., zmax = 1.;
    int   NCONTR = 20;
    PLFLT shade_min, shade_max, sh_color;
    int   sh_cmap   = 1, sh_width;
    int   min_color = 1, min_width = 0, max_color = 0, max_width = 0;

    pls->vpor( .1, .9, .1, .9 );
    pls->wind( 0., 1., 0., twopi );

    for ( i = 0; i < NCONTR; i++ )
    {
        shade_min = zmin + ( zmax - zmin ) * i / (PLFLT) NCONTR;
        shade_max = zmin + ( zmax - zmin ) * ( i + 1 ) / (PLFLT) NCONTR;
        sh_color  = i / (PLFLT) ( NCONTR - 1 );
        sh_width  = 2;
        pls->psty( 0 );

        pls->shade( d, 0., 1., 0., twopi,
            shade_min, shade_max, sh_cmap, sh_color, sh_width,
            min_color, min_width, max_color, max_width,
            true, NULL );
    }

    pls->col( Red );
    pls->box( "bcnst", 0.0, 0, "bcnstv", 0.0, 0 );

// Now do it again, but with the coordinate transformation taken into
// account.

    pls->adv( 0 );

    cxx_pltr2 tr( xg, yg );

    pls->vpas( .1, .9, .1, .9, 1. );
    pls->wind( -1., 1., -1., 1. );

    for ( i = 0; i < NCONTR; i++ )
    {
        shade_min = zmin + ( zmax - zmin ) * i / (PLFLT) NCONTR;
        shade_max = zmin + ( zmax - zmin ) * ( i + 1 ) / (PLFLT) NCONTR;
        sh_color  = i / (PLFLT) ( NCONTR - 1 );
        sh_width  = 2;
        pls->psty( 0 );

        pls->shade( d, 0., 1., 0., twopi,
            shade_min, shade_max, sh_cmap, sh_color, sh_width,
            min_color, min_width, max_color, max_width,
            false, &tr );
    }

    pls->col( Red );

// Now draw the border around the drawing region.

    PLFLT x[65], y[65];

    for ( i = 0; i < 65; i++ )
    {
        x[i] = xg( 63, i );
        y[i] = yg( 63, i );
    }

    pls->line( 65, x, y );

// Finally, let's "squoosh" the plot, and draw it all again.

    PLFLT X1 = 1., X2 = .1, Y1 = 1.2, Y2 = -.2;

    for ( i = 0; i < 64; i++ )
    {
        PLFLT r = i / 64.;
        for ( j = 0; j < 64; j++ )
        {
            PLFLT theta = twopi * j / 64.;

            xg( i, j ) = X1 * r * cos( theta ) +
                         X2 * r*r * cos( 2 * theta );

            yg( i, j ) = Y1 * r * sin( theta ) +
                         Y2 * r*r * sin( 2 * theta );
        }
    }

    PLFLT xmin, xmax, ymin, ymax;
    xg.min_max( xmin, xmax ), yg.min_max( ymin, ymax );

    pls->adv( 0 );

    pls->vpas( .1, .9, .1, .9, 1. );
    pls->wind( xmin, xmax, ymin, ymax );

    for ( i = 0; i < NCONTR; i++ )
    {
        shade_min = zmin + ( zmax - zmin ) * i / (PLFLT) NCONTR;
        shade_max = zmin + ( zmax - zmin ) * ( i + 1 ) / (PLFLT) NCONTR;
        sh_color  = i / (PLFLT) ( NCONTR - 1 );
        sh_width  = 2;
        pls->psty( 0 );

        pls->shade( d, 0., 1., 0., twopi,
            shade_min, shade_max, sh_cmap, sh_color, sh_width,
            min_color, min_width, max_color, max_width,
            false, &tr );
    }

    pls->col( Red );

// Now draw the border around the drawing region.

    for ( i = 0; i < 65; i++ )
    {
        x[i] = xg( 63, i );
        y[i] = yg( 63, i );
    }

    pls->line( 65, x, y );
}

x01cc::x01cc( int argc, const char **argv )
{
    pls = new plstream();

    // Parse and process command line arguments.

    pls->parseopts( &argc, argv, PL_PARSE_FULL );

    // Initialize plplot.

    pls->init();
    plot1();
    plot2();
    delete pls;
}

//--------------------------------------------------------------------------
// Finally!
//--------------------------------------------------------------------------

int main( int argc, const char **argv )
{
    x01cc *x = new x01cc( argc, argv );

    delete x;
}

//--------------------------------------------------------------------------
//                              End of x01cc.cc
//--------------------------------------------------------------------------