# mag2db

Computes magnitude from decibels (dB).

YDB = mag2db(Y)

Y
A matrix.

YDB
A matrix

## Examples

Matrix input:
A = [10     51;4    -1.2];
r1 = mag2db(A)
r2 = mag2db(1)
r1 = [Matrix] 2 x 2
20.00000  34.15140
12.04120       NaN
r2 = 0
Draw a bode plot including the mag2db function:
sys.num=[0 0 0 1];          % Numerator coefficients
sys.den=[1 5 6 0];          % Denominator coefficients
w=logspace(-2,2,100);       % Frequency
magnitude=1./(w.*sqrt(w.^2+3^2).*sqrt(w.^2+2^2));  % Magnitude expression
mag_db=mag2db(magnitude)         % Magnitude in dB
semilogx(w,mag_db);
xlabel('Frequency');
ylabel('Magnitude [dB]');
mag_db = [Matrix] 1 x 100 Row[1] Columns[1:6]
24.43682  23.62871  22.82059  22.01246  21.20432  20.39617
-- (f)orward, (b)ack, (q)uit, (e)xit, (↑), (↓), (←), (→)

## Comments

YDB = mag2db(Y) computes the decibel (dB) value YDB for a magnitude Y.

The formula used to convert between magnitude and decibels is ydb = 20 * log10(y).

Negative values of Y are mapped to NaN.