db2mag

Convert decibels (dB) to magnitude

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    Syntax

    y = db2mag(ydb)

    Description

    y = db2mag(ydb) returns the magnitude measurements, y, that correspond to the decibel (dB) values specified in ydb. The relationship between magnitude and decibels is ydb=20∗log10(y)

    example

    Examples

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    Open Live Script

    For this example, generate a 2-by-3-by-4 array of Gaussian random numbers. Assume the numbers are expressed in decibels and compute the corresponding magnitudes.

    rng('default');
ydb = randn(2,3,4);
y = db2mag(ydb)
    y = 
y(:,:,1) =

    1.0639    0.7710    1.0374
    1.2351    1.1044    0.8602


y(:,:,2) =

    0.9513    1.5098    0.8561
    1.0402    1.3755    1.4182


y(:,:,3) =

    1.0871    1.0858    0.9858
    0.9928    0.9767    1.1871


y(:,:,4) =

    1.1761    1.0804    1.0861
    1.1772    0.8702    1.2065

    Use the definition to check the calculation.

    chck = 10.^(ydb/20)
    chck = 
chck(:,:,1) =

    1.0639    0.7710    1.0374
    1.2351    1.1044    0.8602


chck(:,:,2) =

    0.9513    1.5098    0.8561
    1.0402    1.3755    1.4182


chck(:,:,3) =

    1.0871    1.0858    0.9858
    0.9928    0.9767    1.1871


chck(:,:,4) =

    1.1761    1.0804    1.0861
    1.1772    0.8702    1.2065

    Input Arguments

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    Input array in decibels, specified as a scalar, vector, matrix, or an array. When ydb is nonscalar, db2mag is an element-wise operation.

    Data Types: single | double

    Output Arguments

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    Magnitude measurements, returned as a scalar, vector, matrix, or an array of the same size as ydb.

    Version History

    Introduced in R2008a

    See Also