function.cpp

graph是一款linux/unix下绘制数据曲线图形的程序

/*
 * function.cpp - класс функция, их создание/удаление
 * Copyright (C) 2007 lester
 * 
 * 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 "function.h"

FunctionList functions;

FunctionList &
functions_get_function_list()
{
    return functions;
}

void
graph_render_to_pixbuf();

Function *
functions_add_function_with_dims1 (gdouble xmin, gdouble xmax, gdouble res)
{
    Function *f = new Function();

    f->xmin = xmin;
    f->xmax = xmax;

    f->step = res != 0? res : 0.10;

    int size = static_cast<int>((xmax - xmin) / f->step);

    f->data_x = mgl_create_data_size(size, 0, 0);
    f->data_y = mgl_create_data_size(size, 0, 0);

    mgl_data_fill(f->data_x, xmin, xmax, 'x');

    functions.push_back(f);

    return f;
}

inline void
replace_arguments1(const gchar *src, std::string &dest)
{
    std::string temp;
    guint i;
    for (i = 0; i <= dest.size(); ++i)
    {
        if ( dest[i] == 'x')
        {
            temp += src;
        } else {
            temp += dest[i];
        }
    }

    dest.assign(temp);

}

void
functions_modify_function1 (Function *f, std::string str)
{

        char src[255];

        gdouble xdiff = f->xmax - f->xmin;

        f->eq = g_strdup(str.c_str());

        sprintf (src, "(%f+%f*x)", f->xmin, xdiff);

        replace_arguments1 (src, str);

        mgl_data_modify(f->data_y, str.c_str(), 0);

}

std::string
functions_get_func_info (const gint num)
{
    std::string str(_("Функция:\n"));

    Function *f = functions[num];
    char buf[32];

    str += f->eq;
    str += "\n";

    str += _("Минимум по y:\n\t");

    sprintf (buf, "%f", mgl_data_min(f->data_y));
    str += buf;
    str += "\n";

    str += _("Максимум по y:\n\t");

    sprintf (buf, "%f", mgl_data_max(f->data_y));
    str += buf;
    str += "\n";

    str += "Нули функции:\n\t";

    for (gint i = 0; i < f->data_y->nx-1; ++i)
    {

        if ( (f->data_y->a[i] > 0 && f->data_y->a[i+1] < 0) ||
            (f->data_y->a[i] < 0 && f->data_y->a[i+1] > 0) || f->data_y->a[i] == 0)
        {
            str += "X";
            sprintf (buf, "%f", (f->data_x->a[i]+f->data_x->a[i+1])/2);
            str += buf;
            str += "\n\t";
        }
    }

    return str;
}

void
functions_delete_function (const gint index)
{
    FunctionList::iterator it;
    Function *f;

    f = functions[index];

        for (it = functions.begin(); it != functions.end(); ++it)
        {
            if (*it == f)
            {
                functions.erase(it);
                delete f;
                return;
            }
        }
}

void
functions_delete ()
{
    FunctionList::iterator it;

    for (it = functions.begin(); it != functions.end(); )
    {
        delete *it;
        functions.erase(it);
    }
}

gint
functions_get_count ()
{
    return functions.size();
}