3.20 How to sample a sin signal and plot it?

Sample a sin signal of one second period at 8 times its frequency.

Mathematica

period   = 1; (*sec*) 
f        = 1/period; 
fs       = 8*f; (*sample at 8 times*) 
Ts       = 1/fs; (*sampling period*) 
nSamples = Round[period/Ts]; 
x        = Array[# &, nSamples, {0, period - Ts}]; (*linspace*) 
signal   = {#, Sin[2 Pi f #]} & /@ x; 
text     = MapIndexed[Text[ToString@First[#2], #1, {2, 0}] &, signal]; 
 
Show[ 
  ListPlot[signal, PlotStyle -> Red, Filling -> Axis, Frame -> True, 
   FrameLabel -> {{"f(t)", None}, {"time (sec)", "sampled sin at f2=20 hz"}}, 
   Epilog -> text, PlotTheme -> "Classic", 
   PlotRangePadding -> 0 
   ], 
  Plot[Sin[2 Pi f t], {t, 0, period}, PlotTheme -> "Classic"], 
  BaseStyle -> 10, PlotRange -> {{0, period}, {-1.1, 1.1}}]
 

Matlab

clear all; close all; 
period   = 1; 
f        = 1/period; 
fs       = 8*f; 
Ts       = 1/fs; 
nSamples = round(period/Ts); 
x        = linspace(0,period-Ts,nSamples); 
signal   = sin(2*pi*f*x); 
 
stem(x,signal) 
for i = 1:length(x) 
    text(x(i),sign(signal(i))*0.1+signal(i),num2str(i)) 
end 
hold on; 
x  = linspace(0,period,10*nSamples); 
plot(x,sin(2*pi*f*x)) 
ylim([-1.2,1.2]);