Hi guys

I have a 10th order LPC with coefficients

[1.000000

-0.473154

0.638717

-0.322174

0.243055

-0.210219

0.417031

-0.452547

0.459508

-0.128858]

and i want to plot the LPC spectrum. on the X axis i want to have the

frequency (0Hz-4000Hz)and on the Y axis the magintude in dbs

How i do that in matlab??

# How to plot LPC spectrum

Started by ●July 31, 2007

Reply by ●August 2, 20072007-08-02

Hi,

use freqz command.

[H,F] = freqz(b,a,N, Fs),

where b = [1]; (coeffs of numerator polynomial)

a = [a0 a1 ... a_p] (lpc coefficients)

which are coeffs of denom polynomial.

N = number of points on the frequency axis

(samples of the spectrum), say 256 or 512.

H is the frequency response of the filter.

Fs is the sampling frequency in Hz.

You seem to have used Fs = 8000.

Use

plot(F,log(abs(H)));

You will get the LP spectrum, which is

(mostly) the envelope of short-time

spectrum.

Bye

Guru

--- ee41gi wrote:

> Hi guys

>

> I have a 10th order LPC with coefficients

> [1.000000

> -0.473154

> 0.638717

> -0.322174

> 0.243055

> -0.210219

> 0.417031

> -0.452547

> 0.459508

> -0.128858]

> and i want to plot the LPC spectrum. on the X axis i

> want to have the

> frequency (0Hz-4000Hz)and on the Y axis the

> magintude in dbs

> How i do that in matlab??

>

use freqz command.

[H,F] = freqz(b,a,N, Fs),

where b = [1]; (coeffs of numerator polynomial)

a = [a0 a1 ... a_p] (lpc coefficients)

which are coeffs of denom polynomial.

N = number of points on the frequency axis

(samples of the spectrum), say 256 or 512.

H is the frequency response of the filter.

Fs is the sampling frequency in Hz.

You seem to have used Fs = 8000.

Use

plot(F,log(abs(H)));

You will get the LP spectrum, which is

(mostly) the envelope of short-time

spectrum.

Bye

Guru

--- ee41gi wrote:

> Hi guys

>

> I have a 10th order LPC with coefficients

> [1.000000

> -0.473154

> 0.638717

> -0.322174

> 0.243055

> -0.210219

> 0.417031

> -0.452547

> 0.459508

> -0.128858]

> and i want to plot the LPC spectrum. on the X axis i

> want to have the

> frequency (0Hz-4000Hz)and on the Y axis the

> magintude in dbs

> How i do that in matlab??

>