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/*
* =========================================================================
* utilities - A library of utility functions used by the drawmap program.
* Copyright (c) 1997 Fred M. Erickson
*
* 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
* =========================================================================
*/
/*
* Convert latitudes in degree/min/sec format into decimal degrees.
*
* We assume that there is no decimal point, or other punctuation,
* and that the numeric latitude is in the DDMMSS format,
* and that the latitude is immediately followed by 'N' or 'S'.
*/
double lat_conv(unsigned char *ptr)
{
double lat;
double min;
double sec;
lat = *ptr - '0';
lat = lat * 10.0 + *(ptr + 1) - '0';
min = *(ptr + 2) - '0';
min = min * 10.0 + *(ptr + 3) - '0';
sec = *(ptr + 4) - '0';
sec = sec * 10.0 + *(ptr + 5) - '0';
lat = lat + min / 60.0 + sec / 3600.0;
if (*(ptr + 6) == 'S') {
lat = -lat;
}
return(lat);
}
/*
* Convert longitudes in degree/min/sec format into decimal degrees.
*
* We assume that there is no decimal point, or other punctuation,
* and that the numeric longitude is in the DDDMMSS format,
* and that the longitude is immediately followed by 'W' or 'E'.
*/
double lon_conv(unsigned char *ptr)
{
double lon;
double min;
double sec;
lon = *ptr - '0';
lon = lon * 10.0 + *(ptr + 1) - '0';
lon = lon * 10.0 + *(ptr + 2) - '0';
min = *(ptr + 3) - '0';
min = min * 10.0 + *(ptr + 4) - '0';
sec = *(ptr + 5) - '0';
sec = sec * 10.0 + *(ptr + 6) - '0';
lon = lon + min / 60.0 + sec / 3600.0;
if (*(ptr + 7) == 'W') {
lon = -lon;
}
return(lon);
}
/* Round double values to long integers. */
long
round(double f)
{
long i;
double ff;
i = (long)f;
ff = (double)i;
if (f < 0.0) {
if ((ff - f) >= 0.5) {
return(i - 1);
}
}
else {
if ((f - ff) >= 0.5) {
return(i + 1);
}
}
return(i);
}
/* Find the maximum of two long integers. */
long
max(long a, long b)
{
if (a > b) {
return(a);
}
else {
return(b);
}
}
/* Find the minimum of three doubles */
double
min3(double a, double b, double c)
{
if (a < b) {
if (a < c) {
return(a);
}
else {
return(c);
}
}
else {
if (b < c) {
return(b);
}
else {
return(c);
}
}
}
/* Find the maximum of three doubles */
double
max3(double a, double b, double c)
{
if (a > b) {
if (a > c) {
return(a);
}
else {
return(c);
}
}
else {
if (b > c) {
return(b);
}
else {
return(c);
}
}
}
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