point2d.c

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/*!
 * \file point2d.c
 *
 * \author
 * Lubos Mitas (original program and various modifications)
 *
 * \author
 * H. Mitasova,
 * I. Kosinovsky,
 * D. Gerdes,
 * D. McCauley
 * (GRASS4.1 version of the program and GRASS4.2 modifications)
 *
 * \author modified by McCauley in August 1995
 * \author modified by Mitasova in August 1995, Nov. 1996
 *
 * SPDX-FileCopyrightText: 1993-2006 Helena Mitasova
 * SPDX-FileCopyrightText: GRASS Development Team
 * SPDX-License-Identifier: GPL-2.0-or-later
 */
 
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <grass/gis.h>
#include <grass/vector.h>
#include <grass/dbmi.h>
 
#define POINT2D_C
#include <grass/interpf.h>
 
/* needed for AIX */
#ifdef hz
#undef hz
#endif
 
/*!
 * Checks if interpolating function interp() evaluates correct z-values at
 * given points. If smoothing is used calculate the maximum error caused
 * by smoothing.
 *
 * *ertot* is a RMS deviation of the interpolated surface.
 *
 * \todo
 * Alternative description:
 * ...calculate the maximum and RMS deviation caused by smoothing.
 */
int IL_check_at_points_2d(struct interp_params *params,
                          struct quaddata *data, /*!< current region */
                          double *b,     /*!< solution of linear equations */
                          double *ertot, /*!< total error */
                          double zmin,   /*!< min z-value */
                          double dnorm, struct triple *skip_point)
{
    int n_points = data->n_points;        /* number of points */
    struct triple *points = data->points; /* points for interpolation */
    struct triple point_writeout;
    double east = data->xmax;
    double west = data->x_orig;
    double north = data->ymax;
    double south = data->y_orig;
    double /* rfsta2, errmax, */ h, xx, yy, r2, hz, zz, err, xmm, ymm, r;
    double skip_err;
    int /* n1, */ mm, m;
 
    /* double fstar2; */
    int inside;
 
    /*  if ((site = G_site_new_struct (-1, 2, 0, 1)) == NULL)
       G_fatal_error ("Memory error for site struct"); */
 
    /* fstar2 = params->fi * params->fi / 4.; */
    /* errmax = .0; */
    /* n1 = n_points + 1; */
    for (mm = 1; mm <= n_points; mm++) {
        h = b[0];
        for (m = 1; m <= n_points; m++) {
            xx = points[mm - 1].x - points[m - 1].x;
            yy = points[mm - 1].y - points[m - 1].y;
            r2 = yy * yy + xx * xx;
            if (r2 != 0.) {
                /* rfsta2 = fstar2 * r2; */
                r = r2;
                h = h + b[m] * params->interp(r, params->fi);
            }
        }
        /* modified by helena january 1997 - normalization of z was
           removed from segm2d.c and interp2d.c
           hz = (h * dnorm) + zmin;
           zz = (points[mm - 1].z * dnorm) + zmin;
         */
        hz = h + zmin;
        zz = points[mm - 1].z + zmin;
        err = hz - zz;
        xmm = points[mm - 1].x * dnorm + params->x_orig + west;
        ymm = points[mm - 1].y * dnorm + params->y_orig + south;
        if ((xmm >= west + params->x_orig) && (xmm <= east + params->x_orig) &&
            (ymm >= south + params->y_orig) && (ymm <= north + params->y_orig))
            inside = 1;
        else
            inside = 0;
 
        if (params->create_devi) {
 
            if (inside) { /* if the point is inside the region */
                point_writeout.x = xmm;
                point_writeout.y = ymm;
                point_writeout.z = zz;
                IL_write_point_2d(point_writeout, err);
            }
        }
        (*ertot) += err * err;
    }
 
    /* cv stuff */
    if (params->cv) {
        h = b[0];
        for (m = 1; m <= n_points - 1; m++) {
            xx = points[m - 1].x - skip_point->x;
            yy = points[m - 1].y - skip_point->y;
            r2 = yy * yy + xx * xx;
            if (r2 != 0.) {
                /* rfsta2 = fstar2 * r2; */
                r = r2;
                h = h + b[m] * params->interp(r, params->fi);
            }
        }
        hz = h + zmin;
        zz = skip_point->z + zmin;
        skip_err = hz - zz;
        xmm = skip_point->x * dnorm + params->x_orig + west;
        ymm = skip_point->y * dnorm + params->y_orig + south;
 
        if ((xmm >= west + params->x_orig) && (xmm <= east + params->x_orig) &&
            (ymm >= south + params->y_orig) && (ymm <= north + params->y_orig))
            inside = 1;
        else
            inside = 0;
 
        if (inside) { /* if the point is inside the region */
            point_writeout.x = xmm;
            point_writeout.y = ymm;
            point_writeout.z = zz;
            IL_write_point_2d(point_writeout, skip_err);
        }
    } /* cv */
 
    return 1;
}
 
/*!
 * \brief A function to write out point and deviation at point to database.
 *
 * \param point point to write out
 * \param error deviation at point
 *
 * \return 1
 */
int IL_write_point_2d(struct triple point, double err)
{
 
    char buf[1024];
 
    Vect_reset_line(Pnts);
    Vect_reset_cats(Cats2);
 
    Vect_append_point(Pnts, point.x, point.y, point.z);
    Vect_cat_set(Cats2, 1, count);
    Vect_write_line(&Map2, GV_POINT, Pnts, Cats2);
 
    db_zero_string(&sql2);
    snprintf(buf, sizeof(buf), "insert into %s values ( %d ", ff->table, count);
    db_append_string(&sql2, buf);
 
    snprintf(buf, sizeof(buf), ", %f", err);
    db_append_string(&sql2, buf);
    db_append_string(&sql2, ")");
    G_debug(3, "IL_check_at_points_2d: %s", db_get_string(&sql2));
 
    if (db_execute_immediate(driver2, &sql2) != DB_OK) {
        db_close_database(driver2);
        db_shutdown_driver(driver2);
        G_fatal_error("Cannot insert new row: %s", db_get_string(&sql2));
    }
    count++;
 
    return 1;
}