gray coding

[Yoshiaki Katada]

Hi, all. 

I have a trouble with using gray coding. 

At GABin2DecGenome in API.html, I found the 
sentences, "It contains a mechanism for customized 
encoding of the bit string; binary-to-decimal and one 
form of Gray coding are built in to the library. The 
default is binary-to-decimal mapping (counting in base 2)."

And I also found the function prototypes for the encoding and 
decoding in gavincvt.h. 

But I dont understand how to use the gray coding. 
I'm trying to compare the effect of binary coding and gray coding. 
Its best to tell me the way to use gray coding in ex9.C, a 
sample program in GALIB.  

Please, can somebody help me? 

Thanks. 
Regards, 
Katada