How to 'break' a Gaussian pulse into discrete parts

Hi guys,

I need to break down a continuous Gaussian pulse into 50 discrete parts so I can use each of the 50 individual amplitudes in calculations. Here is what I've tried:

    % Gauss pulse discretisation

tg = 20*10^(-3);         % pulse duration [sec]
B1 = 1;                  % max amplitude [muT]
t  = -tg/2:tg/50:tg/2;   % sampling times
sd = 0.25;               % pulse standard deviation
% pulse shape
p  = B1*exp(-((t-tg/2).^2)/(2*sd.^2));

plot(t,p);

However, the plot looks nothing like a Gaussian pulse of 20ms in duration! If instead the sampling time is changed to

t  = -1:tg/50:1

then the pulse does look like a Gaussian but it is broken down in 5001 parts. Could someone please point me in the right direction? Thank you.