Hi
This is Manoj doing my Btech 3rd year at IIT Kharagpur.I am
working on trigonometric simplication by fu..http://rfdz.ph-noe.ac.at/
fileadmin/Mathematik_Uploads/ACDCA/DESTIME2006/DES_contribs/Fu/
simplification.pdf
i have samll query
this is the code i have written
matchers = (
(a*sin(b+c)**d, (a*sin(b)*cos(c) + a* sin(c)*cos(b))**d, 4),
(a*cos(b+c)**d, (a*cos(b)*cos(c) - a* sin(c)*sin(b))**d, 4),
#(a*tan(b + c)**d, (a*(tan(b) + tan(c))/(1 -
tan(c)*tan(b)))**d),
(a*cos(2*b)**c, (1 - 2*a*sin(b)**2)**c, 3),
(a*sin(2*b)**c, (2*a*sin(b)*cos(b))**c, 3)
)
elif expr.is_Add:
expr = expr.n()
if expr.has(sin,cos) and not expr.has(tan):
for pattern,result,n in matchers:
ret = S.Zero
res = None
if expr.is_Add:
for term in expr.args:
res = term.match(pattern)
if res is not None:
if len(res) == n and (0 not in
res.values()):
<b> # if pattern == (matchers[2][0] or
matchers[3,0]) and res[b].is_Mul:
# ret += term </b>
ret += result.subs(res).expand()
else:
ret += term
if res is None:
ret += term
expr = ret.n()
else:
break
return expr
in trigsimp_recursive simplify.py
The code is not yet completed...i am presetly working on Rule list 2
TR 10-TR 4-TR3 -''TR 11''-TR5.
The problem is (bolded in the code) if the expr contains sin(x).cos(x)
etc which were expanded in TR10 ... now using the TR 11 for expr.args
its converting sin(x),cos(x) into half angle arguements which is not
required and aslo converting cos(2x) in terms of x which is
required.What can a solution so that it understands that there is a
double angle and converts only that.
Is there any sympy function that analyses the arg..ie if there is an
expression sin(x) + sin(y) + sin(x/2) then it should return all the
symbols in the expr as a tuple (x,y,x/2)..so that it can understand
there is a double angle and it can covert only that.
or please suggest me some other matcher which evaluates the expansion
of only double angle..
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