Continued Fractions

*To*: mathgroup at smc.vnet.net*Subject*: [mg75070] Continued Fractions*From*: "Wu Weidong" <ghcgwgwg at singnet.com.sg>*Date*: Mon, 16 Apr 2007 04:13:11 -0400 (EDT)

Hi, I'm working on a function which takes 2 integer values as input, a and b an= d outputs a list of integers corresponding to the continued fraction repres= entation of the rational number a/b. My function is as follows: build[a_Integer,b_Integer, l_List] :== Module[{r==1,q,temp}, While[r!==0, If[a>==b, q==Quotient[a,b]; l==Append[l,q]; r == a-b*q; a == r, temp == a; a == b; b == temp; ]; ]; l ]; Essentially, if the fraction given is less than 1, the first number in the = list is 0. The function then proceeds to find the quotient of the numerator= and denominator (and add that to the list) and the remainder. If the remai= nder is less than one, it takes the reciprocal and splits it into a whole-n= umber part plus another fraction which will be less than 1 and repeat. It s= tops when the remainder is 0. When I tried to run the program, I get the following error messages: Set::shape: Lists {} and {2} are not the same shape. Set::setraw: Cannot assign to raw object 45. Set::shape: Lists {} and {2} are not the same shape. Set::setraw: Cannot assign to raw object 45. Set::shape: Lists {} and {2} are not the same shape. General::stop: Further output of Set::shape will be suppressed during this calculation. Set::setraw: Cannot assign to raw object 45. General::stop: Further output of Set::setraw will be suppressed during this calculation. However, if I just run the While part of the function with a==45, b==16, l= =={}, r==1 (so I can enter the while loop), I can find the right result (2,= 1,4,3), so I believe my algorithm should be correct. The errors only appear= when I put the while loop under the Module structure. What is wrong with my program? Thank you. Regards, Rayne