examples/c/x01c.c

//      Simple line plot and multiple windows demo.
//
// Copyright (C) 2004 Rafael Laboissiere
// Copyright (C) 2000-2018 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; either version 2 of the License, or
// (at your option) any later version.
//
// 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
//
//

#include "plcdemos.h"
#include "plevent.h"
#ifdef PL_HAVE_NANOSLEEP
#include <time.h>
#endif
#ifdef PL_HAVE_UNISTD_H
# include <unistd.h>
#endif

// Variables and data arrays used by plot generators

static PLFLT        x[101], y[101];
static PLFLT        xscale, yscale, xoff, yoff, xs[6], ys[6];
static PLGraphicsIn gin;

static int          locate_mode;
static int          test_xor;
static int          fontset = 1;
static int          pl_parse_skip_mode;
static char         *f_name = NULL;

// Options data structure definition.

static PLOptionTable options[] = {
    {
        "pl_parse_skip",
        NULL,
        NULL,
        &pl_parse_skip_mode,
        PL_OPT_BOOL,
        "-pl_parse_skip",
        "Test using PL_PARSE_SKIP mode for plparseopts (this option must precede non-PLplot options)"
    },
    {
        "locate",               // Turns on test of API locate function
        NULL,
        NULL,
        &locate_mode,
        PL_OPT_BOOL,
        "-locate",
        "Turns on test of API locate function"
    },
    {
        "xor",                  // Turns on test of xor function
        NULL,
        NULL,
        &test_xor,
        PL_OPT_BOOL,
        "-xor",
        "Turns on test of XOR"
    },
    {
        "font",                 // For switching between font set 1 & 2
        NULL,
        NULL,
        &fontset,
        PL_OPT_INT,
        "-font number",
        "Selects stroke font set (0 or 1, def:1)"
    },
    {
        "save",                 // For saving in postscript
        NULL,
        NULL,
        &f_name,
        PL_OPT_STRING,
        "-save filename",
        "Save plot in color postscript `file'"
    },
    {
        NULL,                   // option
        NULL,                   // handler
        NULL,                   // client data
        NULL,                   // address of variable to set
        0,                      // mode flag
        NULL,                   // short syntax
        NULL
    }                           // long syntax
};

PLCHAR_VECTOR        notes[] = { "Make sure you get it right!", NULL };

// Function prototypes

void plot1( int );
void plot2( void );
void plot3( void );

//--------------------------------------------------------------------------
// main
//
// Generates several simple line plots.  Demonstrates:
//   - subwindow capability
//   - setting up the window, drawing plot, and labelling
//   - changing the color
//   - automatic axis rescaling to exponential notation
//   - placing the axes in the middle of the box
//   - gridded coordinate axes
//--------------------------------------------------------------------------

int
main( int argc, char *argv[] )
{
    PLINT digmax, cur_strm, new_strm;
    char  ver[80];
    PLINT i;

// plplot initialization

// Parse and process command line arguments

    plMergeOpts( options, "x01c options", notes );
    // See if -pl_parse_skip has been specified without
    // changing argc or argv
    plparseopts( &argc, argv, PL_PARSE_NODELETE );
    if ( pl_parse_skip_mode )
    {
        printf( "argv prior to call of plparseopts(..., PL_PARSE_SKIP)\n" );
        for ( i = 0; i < argc; i++ )
        {
            printf( "i = %3d, argument = %s\n", i, argv[i] );
        }
        plparseopts( &argc, argv, PL_PARSE_SKIP );
        printf( "argv after call to plparseopts(..., PL_PARSE_SKIP)\n" );
        for ( i = 0; i < argc; i++ )
        {
            printf( "i = %3d, argument = %s\n", i, argv[i] );
        }
    }
    else
    {
        // parse the command line again, and after such parsing
        // argc and argv are typically reduced to 1 and the name
        // of the programme that is being executed.
        plparseopts( &argc, argv, PL_PARSE_FULL );
    }

// Get version number, just for kicks

    plgver( ver );
    fprintf( stdout, "PLplot library version: %s\n", ver );

// Initialize plplot
// Divide page into 2x2 plots
// Note: calling plstar replaces separate calls to plssub and plinit
    plstar( 2, 2 );

// Select font set as per input flag

    if ( fontset )
        plfontld( 1 );
    else
        plfontld( 0 );

// Set up the data
// Original case

    xscale = 6.;
    yscale = 1.;
    xoff   = 0.;
    yoff   = 0.;

// Do a plot

    plot1( 0 );

// Set up the data

    xscale = 1.;
    yscale = 0.0014;
    yoff   = 0.0185;

// Do a plot

    digmax = 5;
    plsyax( digmax, 0 );

    plot1( 1 );

    plot2();

    plot3();

    //
    // Show how to save a plot:
    // Open a new device, make it current, copy parameters,
    // and replay the plot buffer
    //

    if ( f_name )   // command line option '-save filename'

    {
        printf( "The current plot was saved in color Postscript under the name `%s'.\n", f_name );
        plgstrm( &cur_strm );    // get current stream
        plmkstrm( &new_strm );   // create a new one

        plsfnam( f_name );       // file name
        plsdev( "psc" );         // device type

        plcpstrm( cur_strm, 0 ); // copy old stream parameters to new stream
        plreplot();              // do the save by replaying the plot buffer
        plend1();                // finish the device

        plsstrm( cur_strm );     // return to previous stream
    }

// Let's get some user input

    if ( locate_mode )
    {
        for (;; )
        {
            if ( !plGetCursor( &gin ) )
                break;
            if ( gin.keysym == PLK_Escape )
                break;

            pltext();
            printf( "subwin = %d, wx = %f,  wy = %f, dx = %f,  dy = %f\n",
                gin.subwindow, gin.wX, gin.wY, gin.dX, gin.dY );
            printf( "keysym = 0x%02x, button = 0x%02x, string = '%s', type = 0x%02x, state = 0x%02x\n",
                gin.keysym, gin.button, gin.string, gin.type, gin.state );
            plgra();
        }
    }

// Don't forget to call plend() to finish off!

    plend();
    exit( 0 );
}

//--------------------------------------------------------------------------

void
plot1( int do_test )
{
    int   i;
    PLFLT xmin, xmax, ymin, ymax;

    for ( i = 0; i < 60; i++ )
    {
        x[i] = xoff + xscale * ( i + 1 ) / 60.0;
        y[i] = yoff + yscale * pow( x[i], 2. );
    }

    xmin = x[0];
    xmax = x[59];
    ymin = y[0];
    ymax = y[59];

    for ( i = 0; i < 6; i++ )
    {
        xs[i] = x[i * 10 + 3];
        ys[i] = y[i * 10 + 3];
    }

// Set up the viewport and window using PLENV. The range in X is
// 0.0 to 6.0, and the range in Y is 0.0 to 30.0. The axes are
// scaled separately (just = 0), and we just draw a labelled
// box (axis = 0).
//
    plcol0( 1 );
    plenv( xmin, xmax, ymin, ymax, 0, 0 );
    plcol0( 2 );
    pllab( "(x)", "(y)", "#frPLplot Example 1 - y=x#u2" );

// Plot the data points

    plcol0( 4 );
    plpoin( 6, xs, ys, 9 );

// Draw the line through the data

    plcol0( 3 );
    plline( 60, x, y );

// xor mode enable erasing a line/point/text by replotting it again
// it does not work in double buffering mode, however

    if ( do_test && test_xor )
    {
#ifdef PL_HAVE_NANOSLEEP
        PLINT           st;
        struct timespec ts;
        ts.tv_sec  = 0;
        ts.tv_nsec = 50000000;
        plxormod( 1, &st ); // enter xor mode
        if ( st )
        {
            for ( i = 0; i < 60; i++ )
            {
                plpoin( 1, x + i, y + i, 9 );   // draw a point
                nanosleep( &ts, NULL );         // wait a little
                plflush();                      // force an update of the tk driver
                plpoin( 1, x + i, y + i, 9 );   // erase point
            }
            plxormod( 0, &st );                 // leave xor mode
        }
#else
        printf( "The -xor command line option can only be exercised if your "
            "system\nhas nanosleep(), which does not seem to happen.\n" );
#endif
    }
}

//--------------------------------------------------------------------------

void
plot2( void )
{
    int i;

// Set up the viewport and window using PLENV. The range in X is -2.0 to
// 10.0, and the range in Y is -0.4 to 2.0. The axes are scaled separately
// (just = 0), and we draw a box with axes (axis = 1).
//
    plcol0( 1 );
    plenv( -2.0, 10.0, -0.4, 1.2, 0, 1 );
    plcol0( 2 );
    pllab( "(x)", "sin(x)/x", "#frPLplot Example 1 - Sinc Function" );

// Fill up the arrays

    for ( i = 0; i < 100; i++ )
    {
        x[i] = ( i - 19.0 ) / 6.0;
        y[i] = 1.0;
        if ( x[i] != 0.0 )
            y[i] = sin( x[i] ) / x[i];
    }

// Draw the line

    plcol0( 3 );
    plwidth( 2 );
    plline( 100, x, y );
    plwidth( 1 );
}

//--------------------------------------------------------------------------

void
plot3( void )
{
    PLINT space0 = 0, mark0 = 0, space1 = 1500, mark1 = 1500;
    int   i;

// For the final graph we wish to override the default tick intervals, and
// so do not use plenv().
//
    pladv( 0 );

// Use standard viewport, and define X range from 0 to 360 degrees, Y range
// from -1.2 to 1.2.
//
    plvsta();
    plwind( 0.0, 360.0, -1.2, 1.2 );

// Draw a box with ticks spaced 60 degrees apart in X, and 0.2 in Y.

    plcol0( 1 );
    plbox( "bcnst", 60.0, 2, "bcnstv", 0.2, 2 );

// Superimpose a dashed line grid, with 1.5 mm marks and spaces.
// plstyl expects a pointer!
//
    plstyl( 1, &mark1, &space1 );
    plcol0( 2 );
    plbox( "g", 30.0, 0, "g", 0.2, 0 );
    plstyl( 0, &mark0, &space0 );

    plcol0( 3 );
    pllab( "Angle (degrees)", "sine", "#frPLplot Example 1 - Sine function" );

    for ( i = 0; i < 101; i++ )
    {
        x[i] = 3.6 * i;
        y[i] = sin( x[i] * M_PI / 180.0 );
    }

    plcol0( 4 );
    plline( 101, x, y );
}