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//---------------------------------------------------------------------------//
// $Id: x04.java,v 1.8 2004/01/17 16:41:39 rlaboiss Exp $
//---------------------------------------------------------------------------//
//---------------------------------------------------------------------------//
// Copyright (C) 2001 Geoffrey Furnish
// Copyright (C) 2001, 2002 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//---------------------------------------------------------------------------//
//---------------------------------------------------------------------------//
// Implementation of PLplot example 4 in Java.
//---------------------------------------------------------------------------//
package plplot.examples;
import plplot.core.*;
import java.lang.Math;
class x04 {
PLStreamc plsdummy = new PLStreamc();
plplotjavac pls = new plplotjavac();
public static void main( String[] args )
{
x04 x = new x04( args );
}
public x04( String[] args )
{
// Parse and process command line arguments.
pls.plParseOpts( args, pls.PL_PARSE_FULL | pls.PL_PARSE_NOPROGRAM );
// Initialize plplot.
pls.plinit();
pls.plfont(2);
// Make log plots using two different styles.
plot1(0);
plot1(1);
pls.plend();
}
// Log-linear plot.
void plot1( int type )
{
int i;
double[] freql = new double[101];
double[] ampl = new double[101];
double[] phase = new double[101];
double f0, freq;
pls.pladv(0);
// Set up data for log plot.
f0 = 1.0;
for (i = 0; i <= 100; i++) {
freql[i] = -2.0 + i / 20.0;
freq = Math.pow(10.0, freql[i]);
// Unbelievably, Java has no log10() that I can find...
ampl[i] = 20.0 * Math.log(1.0 / Math.sqrt(1.0 + Math.pow((freq / f0), 2.))) / Math.log(10.);
phase[i] = -(180.0 / Math.PI) * Math.atan(freq / f0);
}
pls.plvpor(0.15, 0.85, 0.1, 0.9);
pls.plwind(-2.0, 3.0, -80.0, 0.0);
// Try different axis and labelling styles.
pls.plcol0(1);
switch (type) {
case 0:
pls.plbox("bclnst", 0.0, 0, "bnstv", 0.0, 0);
break;
case 1:
pls.plbox("bcfghlnst", 0.0, 0, "bcghnstv", 0.0, 0);
break;
}
// Plot ampl vs freq.
pls.plcol0(2);
pls.plline(freql, ampl);
pls.plcol0(1);
pls.plptex(1.6, -30.0, 1.0, -20.0, 0.5, "-20 dB/decade");
// Put labels on.
pls.plcol0(1);
pls.plmtex("b", 3.2, 0.5, 0.5, "Frequency");
pls.plmtex("t", 2.0, 0.5, 0.5, "Single Pole Low-Pass Filter");
pls.plcol0(2);
pls.plmtex("l", 5.0, 0.5, 0.5, "Amplitude (dB)");
// For the gridless case, put phase vs freq on same plot.
if (type == 0) {
pls.plcol0(1);
pls.plwind(-2.0, 3.0, -100.0, 0.0);
pls.plbox("", 0.0, 0, "cmstv", 30.0, 3);
pls.plcol0(3);
pls.plline(freql, phase);
pls.plcol0(3);
pls.plmtex("r", 5.0, 0.5, 0.5, "Phase shift (degrees)");
}
}
}
//---------------------------------------------------------------------------//
// End of x04.java
//---------------------------------------------------------------------------//
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