luke
/
ngspice
mirror of https://git.code.sf.net/p/ngspice/ngspice
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Using a real double compare to equal.

This commit is contained in:
dwarning 2008-01-02 18:52:04 +00:00
parent ee9987ca85
commit 28e90e6330
6 changed files with 64 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
ChangeLog
View File

@ -1,9 +1,16 @@
2008-01-02 Dietmar Warning
* src/frontend/outitf.c: Fixed rawfile ascii generation. Same like below.
* src/frontend/inp.c: don't need local buffer w/o getcwd
* src/conf.c: belong spice3 manual ascii is default anyway
* src/misc/missing_math.*, src/include/missig_math.h, /src/frontend/measure.c,
src/spicelib/analysis/dctran.c: Using a real double compare to equal.
2008-01-02 Paolo Nenzi <p.nenzi@ieee.org>
* src/frontend/rawfile.c: Fixed rawfile ascii generation. The prevoius patch
produced incorrect string like v(v(1)) for v(1) in the output file.
2007-12-31 Holger Vogt
* src/frontend/com_chdir.c: fix for the crashing of ngspice under Windows when
don't need buffer w/o getcwd fix for the crashing of ngspice under Windows when
started from windows explorer.
* src/frontend/inp.c: ngspice crashed when executing a file consisting of a simple
control section. Fixed.

12
src/frontend/measure.c
View File

@ -74,7 +74,7 @@ get_volt_time( struct dvec *time, struct dvec *values, double value, char polari
*failed = TRUE;
}
}
if ( AlmostEqualUlps( comp_time, 0, 3 ) ) *failed = TRUE;
if ( AlmostEqualUlps( comp_time, 0, 100 ) ) *failed = TRUE;
return comp_time;
}
@ -139,7 +139,7 @@ measure2( char *meas_type, char *vec_name, char vec_type, double from, double to
*result_time = time->v_realdata[i];
} else {
*result = ( strcmp( meas_type, "max" ) == 0 ) ? max( *result, vec->v_realdata[i] ) : min( *result, vec->v_realdata[i] );
if ( !AlmostEqualUlps( prev_result, *result, 3 ) ) *result_time = time->v_realdata[i];
if ( !AlmostEqualUlps( prev_result, *result, 100 ) ) *result_time = time->v_realdata[i];
}
}
}
@ -164,23 +164,23 @@ measure2( char *meas_type, char *vec_name, char vec_type, double from, double to
// see if y-value constant
for ( i = 0; i < xy_size-1; i++ )
if ( !AlmostEqualUlps( *(y+i), *(y+i+1), 3 ) ) constant_y = FALSE;
if ( !AlmostEqualUlps( *(y+i), *(y+i+1), 100 ) ) constant_y = FALSE;
// Compute Integral (area under curve)
i = 0;
while ( i < xy_size-1 ) {
// Simpson's 3/8 Rule
if ( AlmostEqualUlps( *(width+i), *(width+i+1), 3 ) && AlmostEqualUlps( *(width+i), *(width+i+2), 3 ) ) {
if ( AlmostEqualUlps( *(width+i), *(width+i+1), 100 ) && AlmostEqualUlps( *(width+i), *(width+i+2), 100 ) ) {
sum1 += 3*(*(width+i))*(*(y+i) + 3*(*(y+i+1) + *(y+i+2)) + *(y+i+3))/8;
i += 3;
}
// Simpson's 1/3 Rule
else if ( AlmostEqualUlps( *(width+i), *(width+i+1), 3 ) ) {
else if ( AlmostEqualUlps( *(width+i), *(width+i+1), 100 ) ) {
sum2 += *(width+i)*(*(y+i) + 4*(*(y+i+1)) + *(y+i+2))/3;
i += 2;
}
// Trapezoidal Rule
else if ( !AlmostEqualUlps( *(width+i), *(width+i+1), 3 ) ) {
else if ( !AlmostEqualUlps( *(width+i), *(width+i+1), 100 ) ) {
sum3 += *(width+i)*(*(y+i) + *(y+i+1))/2;
i++;
}

2
src/include/missing_math.h
View File

@ -8,7 +8,7 @@ Copyright 1999 Emmanuel Rouat
#ifndef MISSING_MATH_H_INCLUDED
#define MISSING_MATH_H_INCLUDED
bool AlmostEqualUlps(float, float, int);
bool AlmostEqualUlps(double, double, int);
#ifndef HAVE_ERFC
extern double erfc(double);

51
src/misc/missing_math.c
View File

@ -11,22 +11,59 @@ $Id$
#include "ngspice.h"
#include "missing_math.h"
#ifdef _MSC_VER
typedef __int64 long64;
#else
typedef long long long64;
#endif
/* Initial AlmostEqualULPs version - fast and simple, but */
/* some limitations. */
bool AlmostEqualUlps(float A, float B, int maxUlps)
#define Abs(x) ((x) < 0 ? -(x) : (x))
/* From Bruce Dawson, Comparing floating point numbers,
http://www.cygnus-software.com/papers/comparingfloats/Comparing%20floating%20point%20numbers.htm
Original this function is named AlmostEqual2sComplement but we leave it to AlmostEqualUlps
and can leave the code (measure.c, dctran.c) unchanged. The transformation to the 2's complement
prevent problems around 0.0.
One Ulp is equivalent to a maxRelativeError of between 1/4,000,000,000,000,000 and 1/8,000,000,000,000,000.
Practical: 3 < maxUlps < some hundred's (or thousand's) - depending on numerical requirements.
*/
bool AlmostEqualUlps(double A, double B, int maxUlps)
{
int intDiff;
assert(sizeof(float) == sizeof(int));
long64 aInt, bInt, intDiff;
if (A == B)
return TRUE;
intDiff = abs(*(int*)&A - *(int*)&B);
/* If not - the entire method can not work */
assert(sizeof(double) == sizeof(long64));
/* Make sure maxUlps is non-negative and small enough that the */
/* default NAN won't compare as equal to anything. */
assert(maxUlps > 0 && maxUlps < 4 * 1024 * 1024);
aInt = *(long64*)&A;
/* Make aInt lexicographically ordered as a twos-complement int */
if (aInt < 0)
#ifdef _MSC_VER
aInt = 0x8000000000000000 - aInt;
#else
aInt = 0x8000000000000000LL - aInt;
#endif
bInt = *(long64*)&B;
/* Make bInt lexicographically ordered as a twos-complement int */
if (bInt < 0)
#ifdef _MSC_VER
bInt = 0x8000000000000000 - bInt;
#else
bInt = 0x8000000000000000LL - bInt;
#endif
#ifdef _MSC_VER
intDiff = Abs(aInt - bInt);
#else
intDiff = llabs(aInt - bInt);
#endif
/* printf("A:%e B:%e aInt:%d bInt:%d diff:%d\n", A, B, aInt, bInt, intDiff); */
if (intDiff <= maxUlps)
return TRUE;
return FALSE;
}

2
src/misc/missing_math.h
View File

@ -6,7 +6,7 @@
#ifndef MISSING_MATH_H_INCLUDED
#define MISSING_MATH_H_INCLUDED
bool AlmostEqualUlps(float, float, int);
bool AlmostEqualUlps(double, double, int);
#ifndef HAVE_ERFC
double erfc(double);

8
src/spicelib/analysis/dctran.c
View File

@ -459,7 +459,7 @@ nextTime:
ckt->CKTstat->STAToldIter = ckt->CKTstat->STATnumIter;
if(check_autostop("tran") ||
fabs(ckt->CKTtime - ckt->CKTfinalTime) < ckt->CKTminBreak ||
AlmostEqualUlps( ckt->CKTtime, ckt->CKTfinalTime, 3 ) ) {
AlmostEqualUlps( ckt->CKTtime, ckt->CKTfinalTime, 100 ) ) {
#ifdef STEPDEBUG
printf(" done: time is %g, final time is %g, and tol is %g\n",
ckt->CKTtime,ckt->CKTfinalTime,ckt->CKTminBreak);
@ -526,7 +526,7 @@ resume:
#ifdef XSPICE
/* gtri - begin - wbk - Cut integration order if first timepoint after breakpoint */
//if(ckt->CKTtime == g_mif_info.breakpoint.last)
if ( AlmostEqualUlps( ckt->CKTtime, g_mif_info.breakpoint.last, 3 ) )
if ( AlmostEqualUlps( ckt->CKTtime, g_mif_info.breakpoint.last, 100 ) )
ckt->CKTorder = 1;
/* gtri - end - wbk - Cut integration order if first timepoint after breakpoint */
@ -535,7 +535,7 @@ resume:
/* are we at a breakpoint, or indistinguishably close? */
//if ((ckt->CKTtime == *(ckt->CKTbreaks)) || (*(ckt->CKTbreaks) -
if ( AlmostEqualUlps( ckt->CKTtime, *(ckt->CKTbreaks), 3 ) || (*(ckt->CKTbreaks) -
if ( AlmostEqualUlps( ckt->CKTtime, *(ckt->CKTbreaks), 100 ) || (*(ckt->CKTbreaks) -
(ckt->CKTtime) <= ckt->CKTdelmin)) {
/* first timepoint after a breakpoint - cut integration order */
/* and limit timestep to .1 times minimum of time to next breakpoint,
@ -589,7 +589,7 @@ resume:
#ifdef STEPDEBUG
printf(" brk_pt: %g ckt_time: %g ckt_min_break: %g\n",*(ckt->CKTbreaks), ckt->CKTtime, ckt->CKTminBreak);
#endif
if(AlmostEqualUlps(*(ckt->CKTbreaks),ckt->CKTtime,3) || *(ckt->CKTbreaks) <= (ckt->CKTtime + ckt->CKTminBreak)) {
if(AlmostEqualUlps(*(ckt->CKTbreaks),ckt->CKTtime, 100) || *(ckt->CKTbreaks) <= (ckt->CKTtime + ckt->CKTminBreak)) {
#ifdef STEPDEBUG
printf("throwing out permanent breakpoint times <= current time (brk pt: %g)\n",*(ckt->CKTbreaks));
printf(" ckt_time: %g ckt_min_break: %g\n",ckt->CKTtime, ckt->CKTminBreak);