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//--------------------------------------------------------------------------
// Copyright (C) 2004 Andrew Ross
// Copyright (C) 2004-2014 Alan W. Irwin
//
// 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
//--------------------------------------------------------------------------
//
//--------------------------------------------------------------------------
// Implementation of PLplot example 4 in C++.
//--------------------------------------------------------------------------
#include "plc++demos.h"
#ifdef PL_USE_NAMESPACE
using namespace std;
#endif
class x04 {
public:
x04( int, char ** );
void plot1( int );
private:
// Class data
plstream *pls;
};
x04::x04( int argc, char ** argv )
{
// plplot initialization
pls = new plstream();
// Parse and process command line arguments.
pls->parseopts( &argc, argv, PL_PARSE_FULL );
// Initialize PLplot.
pls->init();
pls->font( 2 );
// Make log plots using two different styles.
plot1( 0 );
plot1( 1 );
// pls->end();
delete pls;
}
// Log-linear plot.
void x04::plot1( int type )
{
int i;
PLFLT *freql = new PLFLT[101];
PLFLT *ampl = new PLFLT[101];
PLFLT *phase = new PLFLT[101];
PLFLT f0, freq;
PLINT nlegend;
const char *text[2], *symbols[2];
PLINT opt_array[2];
PLINT text_colors[2];
PLINT line_colors[2];
PLINT line_styles[2];
PLFLT line_widths[2];
PLINT symbol_numbers[2], symbol_colors[2];
PLFLT symbol_scales[2];
PLFLT legend_width, legend_height;
pls->adv( 0 );
// Set up data for log plot.
f0 = 1.0;
for ( i = 0; i <= 100; i++ )
{
freql[i] = -2.0 + i / 20.0;
freq = pow( 10.0, freql[i] );
ampl[i] = 20.0 * log10( 1.0 / sqrt( 1.0 + pow( ( freq / f0 ), 2. ) ) );
phase[i] = -( 180.0 / M_PI ) * atan( (PLFLT) ( freq / f0 ) );
}
pls->vpor( 0.15, 0.85, 0.1, 0.9 );
pls->wind( -2.0, 3.0, -80.0, 0.0 );
// Try different axis and labelling styles.
pls->col0( 1 );
switch ( type )
{
case 0:
pls->box( "bclnst", 0.0, 0, "bnstv", 0.0, 0 );
break;
case 1:
pls->box( "bcfghlnst", 0.0, 0, "bcghnstv", 0.0, 0 );
break;
}
// Plot ampl vs freq.
pls->col0( 2 );
pls->line( 101, freql, ampl );
pls->col0( 2 );
pls->ptex( 1.6, -30.0, 1.0, -20.0, 0.5, "-20 dB/decade" );
// Put labels on.
pls->col0( 1 );
pls->mtex( "b", 3.2, 0.5, 0.5, "Frequency" );
pls->mtex( "t", 2.0, 0.5, 0.5, "Single Pole Low-Pass Filter" );
pls->col0( 2 );
pls->mtex( "l", 5.0, 0.5, 0.5, "Amplitude (dB)" );
nlegend = 1;
// For the gridless case, put phase vs freq on same plot.
if ( type == 0 )
{
pls->col0( 1 );
pls->wind( -2.0, 3.0, -100.0, 0.0 );
pls->box( "", 0.0, 0, "cmstv", 30.0, 3 );
pls->col0( 3 );
pls->line( 101, freql, phase );
pls->string( 101, freql, phase, "#(728)" );
pls->col0( 3 );
pls->mtex( "r", 5.0, 0.5, 0.5, "Phase shift (degrees)" );
nlegend = 2;
}
// Draw a legend
// First legend entry.
opt_array[0] = PL_LEGEND_LINE;
text_colors[0] = 2;
text[0] = "Amplitude";
line_colors[0] = 2;
line_styles[0] = 1;
line_widths[0] = 1.0;
// note from the above opt_array the first symbol (and box) indices
// do not have to be specified
// Second legend entry.
opt_array[1] = PL_LEGEND_LINE | PL_LEGEND_SYMBOL;
text_colors[1] = 3;
text[1] = "Phase shift";
line_colors[1] = 3;
line_styles[1] = 1;
line_widths[1] = 1.0;
symbol_colors[1] = 3;
symbol_scales[1] = 1.;
symbol_numbers[1] = 4;
symbols[1] = "#(728)";
// from the above opt_arrays we can completely ignore everything
// to do with boxes.
pls->scol0a( 15, 32, 32, 32, 0.70 );
pls->legend( &legend_width, &legend_height,
PL_LEGEND_BACKGROUND | PL_LEGEND_BOUNDING_BOX, 0,
0.0, 0.0, 0.1, 15,
1, 1, 0, 0,
nlegend, opt_array,
1.0, 1.0, 2.0,
1., text_colors, (const char * const *) text,
NULL, NULL, NULL, NULL,
line_colors, line_styles, line_widths,
symbol_colors, symbol_scales, symbol_numbers, (const char **) symbols );
delete[] freql;
delete[] ampl;
delete[] phase;
}
int main( int argc, char ** argv )
{
x04 *x = new x04( argc, argv );
delete x;
}
//--------------------------------------------------------------------------
// End of x04.cc
//--------------------------------------------------------------------------
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