def fr2fc(a,b,t):
"Return continuos fraction fc0 [a1,a2,a3,...at] from a fraction a/b"
a=float(a);b=float(b);t0=0
fc0=[];c=(a/b);pe=int(c);pf=c-pe
while (t0 < t):
fc0.append(pe);t0+=1
c=1.0/pf;pe=int(c);pf=c-pe
return fc0
def fc2dec(fc0):
"Return a number from a continuos fraction fc0 [a1,a2,a3,...]"
ff=list(fc0); ff.reverse()
return reduce(lambda x,y: y+(1.0/x),ff)
def fc2fr(fc0):
"Return a fraction from a continuos fraction fc0 [a1,a2,a3,...]"
fc3=list(fc0)
a=fc3.pop()
b=1
fc3.reverse()
for k in fc3:
a,b=k*a+b,a
return [a,b]
if __name__ == "__main__":
f1= fr2fc(3.141516,1,10)
print f1
for k in range(1,len(f1)+1):
f2= fc2fr(f1[0:k]);print f1[0:k],f2 ,float(f2[0])/f2[1]
print fc2dec(f1)
Diff to Previous Revision
--- revision 1 2014-09-19 07:56:31
+++ revision 2 2014-09-23 14:30:00
@@ -15,19 +15,19 @@
def fc2fr(fc0):
"Return a fraction from a continuos fraction fc0 [a1,a2,a3,...]"
fc3=list(fc0)
- s2=[fc3.pop(),1]
+ a=fc3.pop()
+ b=1
fc3.reverse()
for k in fc3:
- s2.reverse()
- s2=[k*s2[1]+s2[0],s2[1]]
- return s2
+ a,b=k*a+b,a
+ return [a,b]
if __name__ == "__main__":
f1= fr2fc(3.141516,1,10)
print f1
- for k in range(1,lenf1+1):
+ for k in range(1,len(f1)+1):
f2= fc2fr(f1[0:k]);print f1[0:k],f2 ,float(f2[0])/f2[1]
print fc2dec(f1)
