Recently I found that the default g++ (Version 1.37.1 on Unix machine) byte length for data type "double" (8 bytes) is not enough for my project. Is there any way that I can change it to 12 bytes? Reply by e-mail preferably. Thanks for the help. Tachen Ni, Bioengineering Program, Univ. of Mich. e-mail: tcnyyf@caen.engin.umich.edu