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Tweaks to interpolator code.

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This commit is contained in:
curt 2001-03-14 06:24:52 +00:00
parent 95e5e90791
commit 777386ea67
2 changed files with 20 additions and 16 deletions
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30
simgear/math/interpolater.cxx
View File

@ -26,9 +26,7 @@
#include <simgear/compiler.h>
#ifdef __MWERKS__
#include <stdlib.h> // for exit()
#endif
#include STL_STRING
@ -38,14 +36,16 @@
#include "interpolater.hxx"
FG_USING_STD(string);
// Constructor -- loads the interpolation table from the specified
// file
fgINTERPTABLE::fgINTERPTABLE( const string& file ) {
SGInterpTable::SGInterpTable( const string& file ) {
FG_LOG( FG_MATH, FG_INFO, "Initializing Interpolator for " << file );
fg_gzifstream in( file );
if ( !in ) {
if ( !in.is_open() ) {
FG_LOG( FG_GENERAL, FG_ALERT, "Cannot open file: " << file );
exit(-1);
}
@ -55,6 +55,7 @@ fgINTERPTABLE::fgINTERPTABLE( const string& file ) {
while ( in ) {
if ( size < MAX_TABLE_SIZE ) {
in >> table[size][0] >> table[size][1];
in >> skipws;
size++;
} else {
FG_LOG( FG_MATH, FG_ALERT,
@ -67,28 +68,31 @@ fgINTERPTABLE::fgINTERPTABLE( const string& file ) {
// Given an x value, linearly interpolate the y value from the table
double fgINTERPTABLE::interpolate(double x) {
double SGInterpTable::interpolate(double x) {
int i;
double y;
i = 0;
while ( (x > table[i][0]) && (i < size) ) {
// cout << " i = " << i << " table[i][0] = " << table[i][0] << endl;
// cout << " size = " << size << endl;
i++;
}
// printf ("i = %d ", i);
if ( (i == 0) && (x < table[0][0]) ) {
FG_LOG( FG_MATH, FG_ALERT,
"fgInterpolateInit(): lookup error, x to small = " << x );
return(0.0);
FG_LOG( FG_MATH, FG_DEBUG,
"interpolate(): lookup error, x to small = " << x );
return table[0][1];
}
if ( x > table[i][0] ) {
FG_LOG( FG_MATH, FG_ALERT,
"fgInterpolateInit(): lookup error, x to big = " << x );
return(0.0);
// cout << " table[size-1][0] = " << table[size-1][0] << endl;
if ( x > table[size-1][0] ) {
FG_LOG( FG_MATH, FG_DEBUG,
"interpolate(): lookup error, x to big = " << x );
return table[size-1][1];
}
// y = y1 + (y0 - y1)(x - x1) / (x0 - x1)
@ -102,7 +106,7 @@ double fgINTERPTABLE::interpolate(double x) {
// Destructor
fgINTERPTABLE::~fgINTERPTABLE( void ) {
SGInterpTable::~SGInterpTable( void ) {
}

6
simgear/math/interpolater.hxx
View File

@ -40,7 +40,7 @@ FG_USING_STD(string);
#define MAX_TABLE_SIZE 32
class fgINTERPTABLE {
class SGInterpTable {
int size;
double table[MAX_TABLE_SIZE][2];
@ -48,13 +48,13 @@ public:
// Constructor -- loads the interpolation table from the specified
// file
fgINTERPTABLE( const string& file );
SGInterpTable( const string& file );
// Given an x value, linearly interpolate the y value from the table
double interpolate(double x);
// Destructor
~fgINTERPTABLE( void );
~SGInterpTable( void );
};