# coding: utf-8

# # Sounds as Vectors

# In[16]:

import numpy as np
import matplotlib.pyplot as pt

from html5_audio import DEFAULT_RATE, get_html5_wave_player


# Here's a function that produces a 'beep' with a parabola as an 'envelope':

# In[17]:

def make_beep(freq, duration=0.3):
    nsamples = DEFAULT_RATE * duration

    t = np.linspace(0, duration, nsamples)
    data = np.sin(freq*2*np.pi*t)

    ramp = np.linspace(0, 1, nsamples)
    data = data * (1-ramp)**2
    
    return data


# Let's put one into the variable `beep`:

# In[18]:

beep = make_beep(440)


# It's just a numpy array:

# In[19]:

type(beep)


# A pretty long one though:

# In[20]:

beep.shape


# Let's take a look:

# In[21]:

pt.plot(beep)


# This consists of 44100 'samples' (=data points) per second of sound.

# In[22]:

get_html5_wave_player(beep)


# -----------------------
# Can we compose some simple 'music' with this? Let's shoot for three seconds...

# In[10]:

music = np.zeros(DEFAULT_RATE * 3, dtype=np.float32)


# In[23]:

beep1 = make_beep(880, duration=0.8)
beep2 = make_beep(880 * 1.5, duration=0.8)
beep3 = make_beep(880 * 2, duration=0.8)
l = len(beep1)


# In[24]:

music.fill(0)
music[0:l] += beep1
s = int(0.3*DEFAULT_RATE)
music[s:s+l] += 0.1*beep2
s = int(0.6*DEFAULT_RATE)
music[s:s+l] += 0.5*beep3


# In[25]:

get_html5_wave_player(0.3*music)


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