Commit e7ef8d47 authored by Michele Maris's avatar Michele Maris
Browse files

u

parent 45d22d3a

src/yapsut/colored_noise.py

+12 −2
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ Also look at: 
https://pypi.org/project/colorednoise/

pip3 colorednoise --user



Note that the kneew frequency fknee can have any value, it is not restricted to fsamp/2



"""
@@ -30,7 +31,7 @@ class gaussian_colored_noise : 
      return self._wn_sigma

   @property

   def fknee(self) :

      """fknee in units of the fsamp, fknee in [0,0.5]"""

      """fknee>=0 in units of the fsamp"""

      return self._fknee

   @property

   def alpha(self) :
@@ -38,7 +39,7 @@ class gaussian_colored_noise : 
      return self._alpha

   @property

   def freq(self) :

      """the frequencies in units of fsamp in the range [0,0.5]."""

      """the sampled frequencies in units of fsamp in the range [0,0.5]."""

      return self._freq

   @property

   def ps_shape(self) :
@@ -73,6 +74,7 @@ Keywords: 
                    'I' : P(0)**0.5 is left as it is

                    'M' : P(0)**0.5 = wn_mean

                    '100x1' : P(0)**0.5=(1+100*fknee/freq[1])**alpha/2

                    'midf1' : P(0)=P(f[1]/2) = exp((log P[2]-log P[1])/(log f2 - log f1)*(log f1/2 - log f1)+log P(1))

                    note that zero_policy affects the mean value of the chunck but not its variance

                    default value is 'I' that for alpha > 0 gives P(0)=1
@@ -105,6 +107,14 @@ Keywords: 
         self._S[0]=self.wn_mean

      elif self._zero_policy=='100x1' :

         self._S[0]=1 if fknee>ff[1] else (1+100*(self.fknee/self._freq[1])**pl)**0.5

      elif self._zero_policy=='midf1' :

         y1=np.log(self._S[1])

         y2=np.log(self._S[2])

         x1=np.log(self._freq[1])

         x2=np.log(self._freq[2])

         r=(y2-y1)/(x2-x1)

         z=r*(np.log(self._freq[1]/2)-x1)+y1

         self._S[0]=np.exp(z)

      else : # self._zero_policy=='I' :

         # left things as they are

         pass