Develop a code in MATLAB for one dimensional, discrete unit step function.
t=-10:20; %definition of time period step=heaviside(t); %heaviside(x) is Matlab function
and has the value 0 for x < 0, 1 for x > 0,
and 0.5 for x = 0. step(t==0)=1; figure; %command for drawn picture stem(t,step); grid on; xlabel('n'); ylabel('f(n)'); title('1D discrete step function'); axis([-10 10 -1 3]);
Develop a code in MATLAB for sine wave generation.
range=6*pi; %max. time of the signal t=0:0.001:range; %time points A=[1 0.13]; %vector of amplitudes w=[1 3]; %vector of frequencies [Hz] phi=[0 0]; %vector of phases sig1=A(1)*sin(w(1)*t+phi(1)); % definition of particular signals sig2=A(2)*sin(w(2)*t+phi(2)); signal=sig1+sig2; figure; plot(t,sig1,':r','LineWidth',2); hold on; plot(t,sig2,'--g','LineWidth',2); hold on; plot(t,signal,'LineWidth',2); grid on; axis([0 rozsah -1.2*sum(A) 1.2*sum(A)]); xlabel('t [s]'); ylabel('f(t)'); title('Harmonic signals and their sum');
Develop a code in MATLAB for Discrete Fourier transformation and frequency characteristics.
count=32; Ts=4/count; %sampling frequency per=4; %number of periods syms k; %symbol variable syms n; signal=[3.*ones(1,count/4) 2.*ones(1, count /4) ones(1, count /4) zeros(1, count /4)]; fn=[]; for n=1:per fn=[fn signal]; end n=0:count*per-1; figure; stem(n,fn); title('Discrete signal'); axis([0 length(fn) min(abs(fn))-0.5 max(abs(fn))+0.5]); grid on; figure; Xk=fft(signal); %discrete Fourier transformation os=0:length(Xk)-1; stem(os,abs(Xk)); %magnitude frequency characteristic title('Magnitude frequency characteristic'); grid on; figure; stem(os,angle(Xk)); %phase frequency characteristic title('Phase frequency characteristic'); grid on;