gnuplot_i.c

图像置乱代码

  @param	d		Array of doubles.
  @param	n		Number of values in the passed array.
  @param	title	Title of the plot.
  @return	void

  Plots out a 2d graph from a list of doubles. The x-coordinate is the
  index of the double in the list, the y coordinate is the double in
  the list.

  Example:

  @code
    gnuplot_ctrl    *h ;
    double          d[50] ;
    int             i ;

    h = gnuplot_init() ;
    for (i=0 ; i<50 ; i++) {
        d[i] = (double)(i*i) ;
    }
    gnuplot_plot_x(h, d, 50, "parabola") ;
    sleep(2) ;
    gnuplot_close(h) ;
  @endcode
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_x(
    gnuplot_ctrl    *   handle,
    double          *   d,
    int                 n,
    char            *   title
)
{
    int     i ;
	int		tmpfd ;
    char    name[128] ;
    char    cmd[GP_CMD_SIZE] ;
    char    line[GP_CMD_SIZE] ;


	if (handle==NULL || d==NULL || (n<1)) return ;

    /* Open one more temporary file? */
    if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
        fprintf(stderr,
                "maximum # of temporary files reached (%d): cannot open more",
                GP_MAX_TMP_FILES) ;
        return ;
    }

    /* Open temporary file for output   */
	sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
    if ((tmpfd=mkstemp(name))==-1) {
        fprintf(stderr,"cannot create temporary file: exiting plot") ;
        return ;
    }

    /* Store file name in array for future deletion */
    strcpy(handle->to_delete[handle->ntmp], name) ;
    handle->ntmp ++ ;
    /* Write data to this file  */
    for (i=0 ; i<n ; i++) {
		sprintf(line, "%g\n", d[i]);
		write(tmpfd, line, strlen(line));
    }
    close(tmpfd) ;

    /* Command to be sent to gnuplot    */
    if (handle->nplots > 0) {
        strcpy(cmd, "replot") ;
    } else {
        strcpy(cmd, "plot") ;
    }
    
    if (title == NULL) {
        sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle) ;
    } else {
        sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
                      title, handle->pstyle) ;
    }

    /* send command to gnuplot  */
    gnuplot_cmd(handle, line) ;
    handle->nplots++ ;
    return ;
}



/*-------------------------------------------------------------------------*/
/**
  @brief	Plot a 2d graph from a list of points.
  @param	handle		Gnuplot session control handle.
  @param	x			Pointer to a list of x coordinates.
  @param	y			Pointer to a list of y coordinates.
  @param	n			Number of doubles in x (assumed the same as in y).
  @param	title		Title of the plot.
  @return	void

  Plots out a 2d graph from a list of points. Provide points through a list
  of x and a list of y coordinates. Both provided arrays are assumed to
  contain the same number of values.

  @code
    gnuplot_ctrl    *h ;
	double			x[50] ;
	double			y[50] ;
    int             i ;

    h = gnuplot_init() ;
    for (i=0 ; i<50 ; i++) {
        x[i] = (double)(i)/10.0 ;
        y[i] = x[i] * x[i] ;
    }
    gnuplot_plot_xy(h, x, y, 50, "parabola") ;
    sleep(2) ;
    gnuplot_close(h) ;
  @endcode
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_xy(
    gnuplot_ctrl    *   handle,
	double			*	x,
	double			*	y,
    int                 n,
    char            *   title
)
{
    int     i ;
	int		tmpfd ;
    char    name[128] ;
    char    cmd[GP_CMD_SIZE] ;
    char    line[GP_CMD_SIZE] ;

	if (handle==NULL || x==NULL || y==NULL || (n<1)) return ;

    /* Open one more temporary file? */
    if (handle->ntmp == GP_MAX_TMP_FILES - 1) {
        fprintf(stderr,
                "maximum # of temporary files reached (%d): cannot open more",
                GP_MAX_TMP_FILES) ;
        return ;
    }

    /* Open temporary file for output   */
	sprintf(name, "%s/gnuplot-i-XXXXXX", P_tmpdir);
    if ((tmpfd=mkstemp(name))==-1) {
        fprintf(stderr,"cannot create temporary file: exiting plot") ;
        return ;
    }
    /* Store file name in array for future deletion */
    strcpy(handle->to_delete[handle->ntmp], name) ;
    handle->ntmp ++ ;

    /* Write data to this file  */
    for (i=0 ; i<n; i++) {
        sprintf(line, "%g %g\n", x[i], y[i]) ;
		write(tmpfd, line, strlen(line));
    }
    close(tmpfd) ;

    /* Command to be sent to gnuplot    */
    if (handle->nplots > 0) {
        strcpy(cmd, "replot") ;
    } else {
        strcpy(cmd, "plot") ;
    }
    
    if (title == NULL) {
        sprintf(line, "%s \"%s\" with %s", cmd, name, handle->pstyle) ;
    } else {
        sprintf(line, "%s \"%s\" title \"%s\" with %s", cmd, name,
                      title, handle->pstyle) ;
    }

    /* send command to gnuplot  */
    gnuplot_cmd(handle, line) ;
    handle->nplots++ ;
    return ;
}



/*-------------------------------------------------------------------------*/
/**
  @brief	Open a new session, plot a signal, close the session.
  @param	title	Plot title
  @param	style	Plot style
  @param	label_x	Label for X
  @param	label_y	Label for Y
  @param	x		Array of X coordinates
  @param	y		Array of Y coordinates (can be NULL)
  @param	n		Number of values in x and y.
  @return

  This function opens a new gnuplot session, plots the provided
  signal as an X or XY signal depending on a provided y, waits for
  a carriage return on stdin and closes the session.

  It is Ok to provide an empty title, empty style, or empty labels for
  X and Y. Defaults are provided in this case.
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_once(
	char	*	title,
	char	*	style,
	char	*	label_x,
	char	*	label_y,
	double	*	x,
	double	*	y,
	int			n
)
{
	gnuplot_ctrl	*	handle ;

	if (x==NULL || n<1) return ;

	if ((handle = gnuplot_init()) == NULL) return ;
	if (style!=NULL) {
		gnuplot_setstyle(handle, style);
	} else {
		gnuplot_setstyle(handle, "lines");
	}
	if (label_x!=NULL) {
		gnuplot_set_xlabel(handle, label_x);
	} else {
		gnuplot_set_xlabel(handle, "X");
	}
	if (label_y!=NULL) {
		gnuplot_set_ylabel(handle, label_y);
	} else {
		gnuplot_set_ylabel(handle, "Y");
	}
	if (y==NULL) {
		gnuplot_plot_x(handle, x, n, title);
	} else {
		gnuplot_plot_xy(handle, x, y, n, title);
	}
	printf("press ENTER to continue\n");
	while (getchar()!='\n') {}
	gnuplot_close(handle);
	return ;
}




/*-------------------------------------------------------------------------*/
/**
  @brief	Plot a slope on a gnuplot session.
  @param	handle		Gnuplot session control handle.
  @param	a			Slope.
  @param	b			Intercept.
  @param	title		Title of the plot.
  @return	void

  Plot a slope on a gnuplot session. The provided slope has an
  equation of the form y=ax+b

  Example:

  @code
    gnuplot_ctrl    *   h ;
    double              a, b ;

    h = gnuplot_init() ;
    gnuplot_plot_slope(h, 1.0, 0.0, "unity slope") ;
    sleep(2) ;
    gnuplot_close(h) ;
  @endcode
 */
/*--------------------------------------------------------------------------*/
    

void gnuplot_plot_slope(
    gnuplot_ctrl    *   handle,
    double              a,
    double              b,
    char            *   title
)
{
    char    stitle[GP_TITLE_SIZE] ;
    char    cmd[GP_CMD_SIZE] ;

    if (title == NULL) {
        strcpy(stitle, "no title") ;
    } else {
        strcpy(stitle, title) ;
    }

    if (handle->nplots > 0) {
        sprintf(cmd, "replot %g * x + %g title \"%s\" with %s",
                      a, b, title, handle->pstyle) ;
    } else {
        sprintf(cmd, "plot %g * x + %g title \"%s\" with %s",
                      a, b, title, handle->pstyle) ;
    }
    gnuplot_cmd(handle, cmd) ;
    handle->nplots++ ;
    return ;
}


/*-------------------------------------------------------------------------*/
/**
  @brief	Plot a curve of given equation y=f(x).
  @param	h			Gnuplot session control handle.
  @param	equation	Equation to plot.
  @param	title		Title of the plot.
  @return	void

  Plots out a curve of given equation. The general form of the
  equation is y=f(x), you only provide the f(x) side of the equation.

  Example:

  @code
        gnuplot_ctrl    *h ;
        char            eq[80] ;

        h = gnuplot_init() ;
        strcpy(eq, "sin(x) * cos(2*x)") ;
        gnuplot_plot_equation(h, eq, "sine wave", normal) ;
        gnuplot_close(h) ;
  @endcode
 */
/*--------------------------------------------------------------------------*/

void gnuplot_plot_equation(
    gnuplot_ctrl    *   h,
    char            *   equation,
    char            *   title
)
{
    char    cmd[GP_CMD_SIZE];
    char    plot_str[GP_EQ_SIZE] ;
    char    title_str[GP_TITLE_SIZE] ;

    if (title == NULL) {
        strcpy(title_str, "no title") ;
    } else {
        strcpy(title_str, title) ;
    }
    if (h->nplots > 0) {
        strcpy(plot_str, "replot") ;
    } else {
        strcpy(plot_str, "plot") ;
    }

    sprintf(cmd, "%s %s title \"%s\" with %s", 
                  plot_str, equation, title_str, h->pstyle) ;
    gnuplot_cmd(h, cmd) ;
    h->nplots++ ;
    return ;
}

/* vim: set ts=4 et sw=4 tw=75 */