src/mathutils.h: add fvec_quadratic_peak_mag to find the magnitude of interpolated...

[aubio.git] / src / mathutils.h

diff --git a/src/mathutils.h b/src/mathutils.h
index d4905a7..fe04647 100644 (file)
--- a/src/mathutils.h
+++ b/src/mathutils.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
+  Copyright (C) 2003-2014 Paul Brossier <piem@aubio.org>
 
   This file is part of aubio.
 
@@ -234,6 +234,19 @@ smpl_t fvec_median (fvec_t * v);
 */
 smpl_t fvec_quadratic_peak_pos (fvec_t * x, uint_t p);
 
+/** finds magnitude of peak by quadratic interpolation
+
+  See [Quadratic Interpolation of Spectral
+  Peaks](https://ccrma.stanford.edu/~jos/sasp/Quadratic_Peak_Interpolation.html),
+  by Julius O. Smith III
+
+  \param x vector to get the magnitude of the interpolated peak position from
+  \param p index of the peak in vector `x`
+  \return magnitude of interpolated peak
+
+*/
+smpl_t fvec_quadratic_peak_mag (fvec_t * x, smpl_t p);
+
 /** Quadratic interpolation using Lagrange polynomial.
  
   Inspired from ``Comparison of interpolation algorithms in real-time sound