When constructing active filters,  odd values of resistor are often required 
(i.e. something like a 3.14 K Ohm resistor).(It seems best to choose common 
capacitor values and cope with the strange resistances then demanded).

Is there a PD program out there that will work out how best to make up such
a resistance, given fixed resistors of the standard 12 values per decade?.(1,
1.2,1.5,1.8,2.2,3.3 etc ).  It is a common enough problem,  yet I cant 
recall seing a program that tells that Rx+Ry//Rz gives Rq,  starting with 
q and finding prefered values x,y and z.
