meanval -- mean of the values in a view
   -1: vector, float, random values
   -2: vector, float, index is 0
   -3: vector, float, index is size-1
  -11: vector,   int, random values
  -21: vector, float, random values, get/put
  -31: vector, unsigned short, random values
  -32: vector, unsigned short, random values, no index result
  -33: vector, unsigned short, random values, no index result, unsigned long result
 -101: matrix, float