[ferret_users] How to change the value of an element of a variable?

[Xia Changshui <xiacs@xxxxxxxxxx>]

Dear all,

  I have a simple question which puzzles me for a long time. In Ferret how can I change the value of an element of a variable? For instance using set data a.nc I get an array a(100) into Ferret. If I want let the 50th element of the array 

a(50)=(a(49)+a(51))/2.0, How can I achieve this?

 

Thank you.

 

Xia