import numpy as np
import holoviews as hv
from holoviews import opts

hv.extension('matplotlib')

xvals  = np.linspace(-4, 0, 202)
yvals  = np.linspace(4, 0, 202)
xs, ys = np.meshgrid(xvals, yvals)

def waves_image(alpha, beta):
    return hv.Image(np.sin(((ys/alpha)**alpha+beta)*xs))

waves_image(1,0) + waves_image(1,4)

dmap = hv.DynamicMap(waves_image, kdims=['alpha', 'beta'])
dmap

dmap[1,2] + dmap.select(alpha=1, beta=2)

dmap.redim.range(alpha=(1, 5.0), beta=(1, 6.0))

dmap.redim.values(alpha=[1, 2, 3], beta=[0.1, 1.0, 2.5])

dmap.current_key

def shapes(N, radius=0.5): # Positional keyword arguments are fine
    paths = [hv.Path([[(radius*np.sin(a), radius*np.cos(a)) 
                        for a in np.linspace(-np.pi, np.pi, n+2)]], 
                     extents=(-1,-1,1,1)) 
             for n in range(N,N+3)]
    return hv.Overlay(paths)

holomap = hv.HoloMap({(N,r):shapes(N, r) for N in [3,4,5] for r in [0.5,0.75]},  kdims=['N', 'radius'])
dmap = hv.DynamicMap(shapes, kdims=['N','radius'])
holomap + dmap

dtype = type(dmap.data).__name__
length = len(dmap.data)
print("DynamicMap 'dmap' has an {dtype} .data attribute of length {length}".format(dtype=dtype, length=length))

hv.HoloMap(dmap)

hv.HoloMap(dmap[{(2,0.3), (2,0.6), (3,0.3), (3,0.6)}])

samples = hv.HoloMap(dmap[{2,3},{0.5,1.0}])
samples

samples.data.keys()

from holoviews.util import Dynamic
dynamic = Dynamic(samples)
print('After apply Dynamic, the type is a {dtype}'.format(dtype=type(dynamic).__name__))
dynamic

dmap = hv.DynamicMap(shapes, kdims=['N','radius']).redim.range(N=(2,20), radius=(0.5,1.0))

sliced = dmap[4:8, :]
sliced

sliced[:, 0.8:1.0]

xs = np.linspace(0, 2*np.pi,100)

def sin(ph, f, amp):
    return hv.Curve((xs, np.sin(xs*f+ph)*amp))

kdims=[hv.Dimension('phase', range=(0, np.pi)),
       hv.Dimension('frequency', values=[0.1, 1, 2, 5, 10]),
       hv.Dimension('amplitude', values=[0.5, 5, 10])]

waves_dmap = hv.DynamicMap(sin, kdims=kdims)

wave_grid = waves_dmap.overlay('amplitude').grid('frequency')
wave_grid.opts(fig_size=200, show_legend=True)

opts.defaults(opts.Path(color=hv.Palette('Blues')))

def spiral_equation(f, ph, ph2):
    r = np.arange(0, 1, 0.005)
    xs, ys = (r * fn(f*np.pi*np.sin(r+ph)+ph2) for fn in (np.cos, np.sin))
    return hv.Path((xs, ys))

spiral_dmap = hv.DynamicMap(spiral_equation, kdims=['f','ph','ph2'])
spiral_dmap = spiral_dmap.redim.values(
    f=np.linspace(1, 10, 10),
    ph=np.linspace(0, np.pi, 10),
    ph2=np.linspace(0, np.pi, 4))

spiral_grid = spiral_dmap.groupby(['f', 'ph'], group_type=hv.NdOverlay, container_type=hv.GridSpace)
spiral_grid.opts(
    opts.GridSpace(xaxis=None, yaxis=None),
    opts.Path(bgcolor='white', xaxis=None, yaxis=None))

ls = np.linspace(0, 10, 200)
xx, yy = np.meshgrid(ls, ls)

def cells(time):
    return hv.Image(time*np.sin(xx+time)*np.cos(yy+time), vdims='Intensity')

dmap = hv.DynamicMap(cells, kdims='time').redim.range(time=(1,20))
(dmap + dmap.redim.range(Intensity=(0,10))).opts(
    opts.Image(axiswise=True))