This code example is to animate VBAP, VBIP, MDAP interactively

In [6]:

    

import numpy as np
import scipy as sp
from numpy.linalg import inv

def vectorpan(xys,xyls,simplices):
    g=np.zeros(xyls.shape[1])
    for n in range(0,simplices.shape[0]):
        na=simplices[n,0]
        nb=simplices[n,1]
        M=np.array([xyls[:,na],xyls[:,nb]]).T
        gnm=np.dot(inv(M),xys)
        if np.sum(gnm<-1e-3)==0:
            g[na]=gnm[0]
            g[nb]=gnm[1]
            break
    return g


def r_vector(g,xyls):
    thx=xyls[0,:]
    thy=xyls[1,:]
    rx=np.dot(thx,g).T
    ry=np.dot(thy,g).T
    normalizer=sum(g,0)
    rx/=normalizer
    ry/=normalizer
    return np.array([rx,ry])

from scipy.spatial import ConvexHull
import math

L=5
phils=np.arange(0,L)*2*np.pi/L
xyls=np.array([np.cos(phils),np.sin(phils)])
phis=0
xys=np.array([np.cos(phis),np.sin(phis)])
qh=ConvexHull(xyls.T)
    
def get_panning_gains(xys,xyls,simplices,pantype):
    if (pantype == 'MDAP') or (pantype == 'MDIP'):
        alpha=np.arccos(np.dot(xyls[:,0],xyls[:,1]))
        R=np.array([np.cos(alpha/2), -np.sin(alpha/2), np.sin(alpha/2), np.cos(alpha/2)]).reshape(2,2)
        xys2=np.dot(R,xys)
        xys3=np.dot(R.T,xys)
        g=vectorpan(xys,xyls,simplices)+vectorpan(xys2,xyls,simplices)+vectorpan(xys3,xyls,simplices)
        if pantype == 'MDIP':
            g=np.abs(g)
            g=np.sqrt(g)
        g/=np.sqrt(np.sum(g**2))
    elif pantype == 'VBAP':
        g=vectorpan(xys,xyls,simplices)
    else:
        g=np.sqrt(np.abs(vectorpan(xys,xyls,simplices)))
    return g

from bokeh.plotting import figure, output_file, show
from bokeh.io import push_notebook, output_notebook
import ipywidgets as widgets
import time, threading

L_widget = widgets.IntSlider(min=4, max=12, step=1,value=L,description="L")
phis_widget= widgets.FloatSlider(min=-180.0,max=180.0,step=1.0,value=0.0,description="phi")
pantype_widget= widgets.SelectionSlider(options=['VBAP','VBIP','MDAP','MDIP'],value='VBAP',description="weight")
animate_widget=widgets.Checkbox(value=False,description="anim")

L=L_widget.value;
phils=np.mod((2*np.pi*np.arange(0,L))/L+np.pi,2*np.pi)-np.pi
xys=np.array([np.cos(phis),np.sin(phis)])
qh=ConvexHull(xyls.T)
simplices=qh.simplices
phis=phis_widget.value*np.pi/180.0
xys=np.array([np.cos(phis),np.sin(phis)])
pantype=pantype_widget.value
gls=get_panning_gains(xys,xyls,simplices,pantype)

output_notebook()
p = figure(title="2D VBAP, VBIP, MDAP, and MDIP Panning",plot_width=600, plot_height=270, x_range=(-180,180), y_range=(-.4,1.1))
ll=p.circle(phils*180/np.pi, gls , line_width=3, color="red")
pp=p.line(np.array([phis, phis])*180/np.pi, np.array([0, 1]), color="black")
rE=r_vector(gls**2,xyls)
dirE=np.arctan2(rE[1],rE[0])*180/np.pi;
lenE=np.sqrt(np.sum(rE**2))
prE=p.line(np.array([1, 1])*dirE, np.array([0, 1])*lenE, color="red",line_width=3,legend="rE")
rV=r_vector(gls,xyls)
dirV=np.arctan2(rV[1],rV[0])*180/np.pi;
lenV=np.sqrt(np.sum(rV**2))
prV=p.line(np.array([1, 1])*dirV, np.array([0, 1])*lenV, color="green",line_width=3,legend="rV")
show(p,notebook_handle=True)

def update_plot(xys,xyls,simplices,pantype):
    pp.data_source.data['x']=np.mod(np.array([1, 1])*np.arctan2(xys[1],xys[0])*180/np.pi+180,360)-180
    gls=get_panning_gains(xys,xyls,simplices,pantype)
    ll.data_source.data['y']=gls
    ll.data_source.data['x']=np.arctan2(xyls[1,:],xyls[0,:])*180/np.pi
    rE=r_vector(gls**2,xyls)
    dirE=np.arctan2(rE[1],rE[0])*180/np.pi;
    lenE=np.sqrt(np.sum(rE**2))
    prE.data_source.data['x']=np.array([1, 1])*dirE
    prE.data_source.data['y']=np.array([0, 1])*lenE
    rV=r_vector(gls,xyls)
    dirV=np.arctan2(rV[1],rV[0])*180/np.pi;
    lenV=np.sqrt(np.sum(rV**2))
    prV.data_source.data['x']=np.array([1, 1])*dirV
    prV.data_source.data['y']=np.array([0, 1])*lenV
    push_notebook()

def on_value_change(change):
    global simplices
    phis=phis_widget.value*np.pi/180.0
    xys=np.array([np.cos(phis),np.sin(phis)])
    pantype=pantype_widget.value
    L=L_widget.value
    phils=np.mod((2*np.pi*np.arange(0,L))/L+np.pi,2*np.pi)-np.pi
    xyls=np.array([np.cos(phils),np.sin(phils)])
    if change.owner == L_widget:
        qh=ConvexHull(xyls.T)
        simplices=qh.simplices
    update_plot(xys,xyls,simplices,pantype)

#widgets.jslink((play,'value'),(phis_widget,'value'))
#interactive(update_plot, L=L_widget, phis=phis_widget, weight=weights_widget)

phis_widget.observe(on_value_change,names='value')
L_widget.observe(on_value_change,names='value')
pantype_widget.observe(on_value_change,names='value')

def animate_plot(change):
    if animate_widget.value:
        phis=phis_widget.value
        phis=np.mod(phis+3+180,360)-180
        phis_widget.value=phis
        threading.Timer(0.001, animate_plot,[1]).start()

animate_widget.observe(animate_plot,names='value')
widgets.HBox([phis_widget,L_widget,pantype_widget,animate_widget])


    

    






    

        
        Loading BokehJS ...