speccentroid

The speccentroid function determines the spectral centroid or “center of mass” for any given spectral power distribution (SPD) as in the following equation:

\lambda_{\textrm{c}} = \frac{\sum \lambda \cdot s(\lambda) \,\textrm{d}\lambda}{\sum s(\lambda) \,\textrm{d}\lambda}

See also: specpeak

Usage:

sc = speccentroid(lam,spec)

Where:

Parameter	Description
sc	Returns the spectral centroid, or center of mass wavelength.
lam	Specifies the wavelengths, vector or matrix.
spec	Specifies the spectral power distribution(s), vector or matrix.

Examples:

Determine spectral centroid of the V(\lambda) curve:

lam = 380:780;
VL = ciespec(lam,'VL');
sc = speccentroid(lam,VL)

% plotting the result
plot(lam,VL)
grid minor
hold on
plot([sc sc],[0 1],'k--')
xlabel('\lambda in nm')
ylabel('relative SPD')
hold off

See also: ciespec

Result:

sc = 560.19

Determine the spectral centroids of the α-opic functions:

lam = 380:780;
spec = ciespec(lam,'aopic');
aopiccent = speccentroid(lam,spec)

See also: ciespec

Result:

aopiccent =

   450.03
   536.41
   561.34
   502.40
   489.69

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