Attr3dhead - Info on header keys
Attr3d <in.H pars
[nkeys]number of keys to calculate parameters on.
name of key to calc parameters on (only necessary if nkeys < less than nkeys in dataset
string containing keys to print (can use instead of nkeys, keys_). The list should be separeted by :
[1000000] maximum amount of memory for Attr to use.
[1] 0-print only min,max, and non-zero 1-print above plust rms,mean, and norm
Calculates statistics for header values of SEP3d dataset
util/info =cut