PetscFOpen with mode "a+"

[(Rebecca) Xuefei YUAN]

Hi,All,

I tried to use PetscFOpen to write the numerical result to a file, and  
I would like to use the mode "a+" to add my result to the existing  
content in my file. However, whenever the new result comes out, it  
will overwrite the existing content in the file. Is there any problem  
here?

Thanks a lot!

Rebecca