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

inpptree.c, PTdifferentiate(), cleanup, use a #define 

to express the expressions arguments more readable
This commit is contained in:
rlar 2016-12-21 20:58:25 +01:00
parent d696aa8781
commit f12ff5464e
1 changed files with 36 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
src/spicelib/parser/inpptree.c
View File

@ -296,33 +296,37 @@ static INPparseNode *PTdifferentiate(INPparseNode * p, int varnum)
break;
case PT_POWER:
if (p->right->type == PT_CONSTANT) {
#define a p->left
#define b p->right
if (b->type == PT_CONSTANT) {
/*
* D(f^C) = C * f^(C-1) * D(f)
* D(a^C) = C * a^(C-1) * D(a)
*/
arg1 = PTdifferentiate(p->left, varnum);
arg1 = PTdifferentiate(a, varnum);
newp = mkb(PT_TIMES, mkb(PT_TIMES,
mkcon(p->right->constant),
mkb(PT_POWER, p->left,
mkcon(p->right->constant - 1))),
mkcon(b->constant),
mkb(PT_POWER, a,
mkcon(b->constant - 1))),
arg1);
} else {
/*
* D(f^g) = D(exp(g*log(f)))
* = exp(g*log(f)) * D(g*log(f))
* = exp(g*log(f)) * (D(g)*log(f) + g*D(f)/f)
* D(a^b) = D(exp(b*log(a)))
* = exp(b*log(a)) * D(b*log(a))
* = exp(b*log(a)) * (D(b)*log(a) + b*D(a)/a)
*/
arg1 = PTdifferentiate(p->left, varnum);
arg2 = PTdifferentiate(p->right, varnum);
arg1 = PTdifferentiate(a, varnum);
arg2 = PTdifferentiate(b, varnum);
newp = mkb(PT_TIMES, mkf(PTF_EXP, mkb(PT_TIMES,
p->right, mkf(PTF_LOG,
p->left))),
b, mkf(PTF_LOG,
a))),
mkb(PT_PLUS,
mkb(PT_TIMES, p->right,
mkb(PT_DIVIDE, arg1, p->left)),
mkb(PT_TIMES, arg2, mkf(PTF_LOG, p->left))));
mkb(PT_TIMES, b,
mkb(PT_DIVIDE, arg1, a)),
mkb(PT_TIMES, arg2, mkf(PTF_LOG, a))));
}
#undef b
#undef a
break;
case PT_TERN: /* ternary_fcn(cond,exp1,exp2) */
@ -552,17 +556,19 @@ static INPparseNode *PTdifferentiate(INPparseNode * p, int varnum)
pow(a,b)
p->left: ',' p->left->left: a p->left->right: b
*/
#define a p->left->left
#define b p->left->right
if (p->left->right->type == PT_CONSTANT) {
if (b->type == PT_CONSTANT) {
/*
* D(f^C) = C * f^(C-1) * D(f)
*/
arg1 = PTdifferentiate(p->left->left, varnum);
arg1 = PTdifferentiate(a, varnum);
newp = mkb(PT_TIMES, mkb(PT_TIMES,
mkcon(p->left->right->constant),
mkb(PT_POWER, p->left->left,
mkcon(p->left->right->constant - 1))),
mkcon(b->constant),
mkb(PT_POWER, a,
mkcon(b->constant - 1))),
arg1);
#ifdef TRACE
printf("pow, %s, returns; ", __func__);
@ -575,17 +581,19 @@ static INPparseNode *PTdifferentiate(INPparseNode * p, int varnum)
* = exp(g*log(f)) * D(g*log(f))
* = exp(g*log(f)) * (D(g)*log(f) + g*D(f)/f)
*/
arg1 = PTdifferentiate(p->left->left, varnum);
arg2 = PTdifferentiate(p->left->right, varnum);
arg1 = PTdifferentiate(a, varnum);
arg2 = PTdifferentiate(b, varnum);
newp = mkb(PT_TIMES, mkf(PTF_EXP, mkb(PT_TIMES,
p->left->right, mkf(PTF_LOG,
p->left->left))),
b, mkf(PTF_LOG,
a))),
mkb(PT_PLUS,
mkb(PT_TIMES, p->left->right,
mkb(PT_DIVIDE, arg1, p->left->left)),
mkb(PT_TIMES, arg2, mkf(PTF_LOG, p->left->left))));
mkb(PT_TIMES, b,
mkb(PT_DIVIDE, arg1, a)),
mkb(PT_TIMES, arg2, mkf(PTF_LOG, a))));
}
return mkfirst(newp, p);
#undef b
#undef a
}
break;