c# - Dynamic-length array using Singleton -

okay, way outside comfort zone here , struggling new concepts hope can make myself clear.
understand it, global variables bad in c# (and dangerous in general) don't want debate. after research led believe singletons can help. please feel free offer alternatives here if wrong situation describe below.

trying create dynamic multi-dimensional array contain numerical data. matrix varying in size , must created during runtime (i pulling data logging device through gui).
see being solution create class has variable can can get , set dynamic size.

public class mysingleton {     public static int datasize { get; set; }     public double[] dataset = new double[datasize] { get; set; }                } 

something effect wrong , not work. have been trying research how initialize array @ runtime cannot figure out, feel don't know terms search. help?

what want use explicit (rather implicit) backing fields can add logic getter , setter. this:

public class mysingleton {     private static int _datasize;    // might want set sensible default     public static int datasize      {          { return _datasize; }         set          {              _datasize = value;             _dataset = null;        // changing size implicitly clear array - write code resize if wanted         }     }     private static double[] _dataset;     public static double[] dataset      {                   {             if (_dataset == null)              {                 _dataset = new double[_datasize];             }             return _dataset;         }         // can include setter if want let consumer set dataset directly - in case should update _datasize field.     }                }