[pspp] / src / chart.c

/* PSPP - computes sample statistics.
   Copyright (C) 2004 Free Software Foundation, Inc.
   Written by John Darrington <john@darrington.wattle.id.au>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program 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
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA. */

#include <config.h>
#include <stdio.h>
#include <plot.h>
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include <float.h>
#include <assert.h>
#include <math.h>

#include "chart.h"
#include "str.h"


const char *data_colour[] = {
  "brown",
  "red",
  "orange",
  "yellow",
  "green",
  "blue",
  "violet",
  "grey",
  "pink"
};



int
chart_initialise(struct chart *chart)
{

  chart->pl_params = pl_newplparams();

  chart->lp = pl_newpl_r ("X",0,stdout,stderr,chart->pl_params);

  if (pl_openpl_r (chart->lp) < 0)      /* open Plotter */
      return 1;

  pl_fspace_r (chart->lp, 0.0, 0.0, 1000.0, 1000.0); /* set coordinate system */
  pl_flinewidth_r (chart->lp, 0.25);    /* set line thickness */
  pl_pencolorname_r (chart->lp, "black"); 

  pl_erase_r (chart->lp);               /* erase graphics display */
  pl_filltype_r(chart->lp,0);



  pl_savestate_r(chart->lp);

  /* Set default chartetry */
  chart->data_top =   900;
  chart->data_right = 800;
  chart->data_bottom = 120;
  chart->data_left = 150;
  chart->abscissa_top = 70;
  chart->ordinate_right = 120;
  chart->title_bottom = 920;
  chart->legend_left = 810;
  chart->legend_right = 1000;
  chart->font_size = 0;
  strcpy(chart->fill_colour,"red");


  /* Get default font size */
  if ( !chart->font_size) 
    chart->font_size = pl_fontsize_r(chart->lp, -1);

  /* Draw the data area */
  pl_box_r(chart->lp, 
           chart->data_left, chart->data_bottom, 
           chart->data_right, chart->data_top);

  return 0;

}



/* Draw a tick mark at position
   If label is non zero, then print it at the tick mark
*/
void
draw_tick(struct chart *chart, 
          enum tick_orientation orientation, 
          double position, 
          const char *label, ...)
{
  const int tickSize = 10;

  pl_savestate_r(chart->lp);

  pl_move_r(chart->lp, chart->data_left, chart->data_bottom);

  if ( orientation == TICK_ABSCISSA ) 
    pl_flinerel_r(chart->lp, position, 0, position, -tickSize);
  else if (orientation == TICK_ORDINATE ) 
      pl_flinerel_r(chart->lp, 0, position, -tickSize, position);
  else
    assert(0);

  if ( label ) {
    char buf[10];
    va_list ap;
    va_start(ap,label);
    vsnprintf(buf,10,label,ap);

    if ( orientation == TICK_ABSCISSA ) 
      pl_alabel_r(chart->lp, 'c','t', buf);
    else if (orientation == TICK_ORDINATE ) 
      {
        if ( fabs(position) < DBL_EPSILON )
            pl_moverel_r(chart->lp, 0, 10);

        pl_alabel_r(chart->lp, 'r','c', buf);
      }

    va_end(ap);
  }
    
  pl_restorestate_r(chart->lp);
}




/* Write the title on a chart*/
void  
chart_write_title(struct chart *chart, const char *title, ...)
{
  va_list ap;
  char buf[100];

  pl_savestate_r(chart->lp);
  pl_ffontsize_r(chart->lp,chart->font_size * 1.5);
  pl_move_r(chart->lp,chart->data_left, chart->title_bottom);

  va_start(ap,title);
  vsnprintf(buf,100,title,ap);
  pl_alabel_r(chart->lp,0,0,buf);
  va_end(ap);

  pl_restorestate_r(chart->lp);
}



void
chart_finalise(struct chart *chart)
{
  pl_restorestate_r(chart->lp);

  if (pl_closepl_r (chart->lp) < 0)     /* close Plotter */
    {
      fprintf (stderr, "Couldn't close Plotter\n");
    }


  pl_deletepl_r(chart->lp);

  pl_deleteplparams(chart->pl_params);

}



  
/* Adjust tick to be a sensible value 
   ie:  ... 0.1,0.2,0.5,   1,2,5,  10,20,50 ... */
double
chart_rounded_tick(double tick)
{

  int i;

  double diff = DBL_MAX;
  double t = tick;
    
  static const double standard_ticks[] = {1, 2, 5, 10};

  const double factor = pow(10,ceil(log10(standard_ticks[0] / tick))) ;

  for (i = 3  ; i >= 0 ; --i) 
    {
      const double d = fabs( tick - standard_ticks[i] / factor ) ;

      if ( d < diff ) 
        {
          diff = d;
          t = standard_ticks[i] / factor ;
        }
    }

  return t;
    
}