magnitude and phase response

i have to plot magnitude and phase response of a real time signal

my code:

t = linspace(0,1,1000); A = 10; f = 5; phi = pi/4;

sig = A*sin(2*pi*f*t + phi); plot(t , sig)

res = fft(sig); plot(t,res) res1 = abs(sig); plot(t,res1)

i am confused in fft part, or suggest me other commands through which i can find magnitude and phase

Answer 1

[Daniel Shub]

Maybe I am missing something, but isn't the magnitude A and the phase phi?

[pinna Afff]

i have to plot magnitude and phase response of this sinosoidal

Answer 2

[Greg Heath]

N = 1000, tmax = 1, dt = tmax/(N-1), Fs = 1/dt, T = N*dt

t = linspace(0,tmax,N);

t = dt*linspace(0,N-1,N);

t = linspace(0,T-dt,N);

A = 10; f0 = 5; phi = pi/4;

sig = A*cos(2*pi*f0*t + phi); % NOTE: cos, NOT sin

figure(1); plot(t , sig)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

df = Fs/N, fmax = (N-1)*df

f = linspace(0,fmax,N);

f = df*linspace(0,N-1,N);

f = linspace(0,Fs-df,N);

SIG = fft(sig); absSIG = abs(SIG); phaseSIG = angle(SIG); figure(2), t(t,res) rsees1 = abs(sig); plot(t,res1)

[Greg Heath]

Delete:

t(t,res) rsees1 = abs(sig); plot(t,res1)