This is machine translation

Translated by Microsoft
Mouse over text to see original. Click the button below to return to the English verison of the page.


Convert power to decibels




ydb = pow2db(y) expresses in decibels (dB) the power measurements specified in y. The relationship between power and decibels is ydb = 10 log10(y).


collapse all

Generate 1024 samples of a noisy sinusoid having a normalized frequency of $2\pi/3$ rad/sample. Estimate the power spectrum of the signal using pwelch. Express the estimate in decibels and plot it.

n = 0:1024-1;
x = cos(2*pi*n/3) + randn(size(n));

[pxx,w] = pwelch(x,'power');

dB = pow2db(pxx);

xlabel('\omega / \pi')
ylabel('Power (dB)')

Repeat the computation using pwelch without output arguments.


Input Arguments

collapse all

Input array, specified as a scalar, vector, matrix, or N-D array. When y is nonscalar, pow2db is an element-wise operation.

Data Types: single | double

Output Arguments

collapse all

Power measurements in decibels, returned as a scalar, vector, matrix, or N-D array of the same size as y.

See Also

| | |

Introduced in R2007b

Was this topic helpful?