Python vq.vq函数代码示例

def _get_centroid_mask(overtones):
    flat = overtones.reshape((len(overtones) * 48, overtones.shape[2]))
    f0flat = flat[np.argmax(flat, 1) == 0]
    f0flat = f0flat[np.max(f0flat, 1) > 0]
    f0flat = (f0flat.T / np.max(f0flat, 1)).T

    centroids, distortion = kmeans(f0flat, 24)
    codes, dists = vq(f0flat, centroids)
    #centroids = centroids[np.bincount(codes) > np.median(np.bincount(codes))]    
    flat_norm = (flat.T / np.max(flat, 1)).T
    codes, dists = vq(flat_norm, centroids)

    flat_filtered = np.copy(flat)

    for i, (s, c) in enumerate(zip(flat, codes)):
        if c < 0 or c > len(centroids):
            continue

        centroid = centroids[c]
        centroid_denorm = centroid * np.max(s)
        flat_filtered[i, 1:] -= centroid_denorm[1:]
        flat_filtered[i, 1:] = np.maximum(flat_filtered[i, 1:], 0)

    overtones_filtered = flat_filtered.reshape(overtones.shape)

    return overtones_filtered

def getImageDescriptor(model, im, conf):
	im = standardizeImage(im)
	height, width = im.shape[:2]
	numWords = model.vocab.shape[1]
	frames, descrs = getPhowFeatures(im, conf.phowOpts)
	# quantize appearance
	if model.quantizer == 'vq':
		binsa, _ = vq(descrs.T, model.vocab.T)
	elif model.quantizer == 'kdtree':
		raise ValueError('quantizer kdtree not implemented')
	else:
		raise ValueError('quantizer {0} not known or understood'.format(model.quantizer))
	hist = []
	for n_spatial_bins_x, n_spatial_bins_y in zip(model.numSpatialX, model.numSpatialX):
		binsx, distsx = vq(frames[0, :], linspace(0, width, n_spatial_bins_x))
		binsy, distsy = vq(frames[1, :], linspace(0, height, n_spatial_bins_y))
		# binsx and binsy list to what spatial bin each feature point belongs to
		if (numpy.any(distsx < 0)) | (numpy.any(distsx > (width/n_spatial_bins_x+0.5))):
			print ("something went wrong")
			import pdb; pdb.set_trace()
		if (numpy.any(distsy < 0)) | (numpy.any(distsy > (height/n_spatial_bins_y+0.5))):
			print ("something went wrong")
			import pdb; pdb.set_trace()
		# combined quantization
		number_of_bins = n_spatial_bins_x * n_spatial_bins_y * numWords
		temp = arange(number_of_bins)
		# update using this: http://stackoverflow.com/questions/15230179/how-to-get-the-linear-index-for-a-numpy-array-sub2ind
		temp = temp.reshape([n_spatial_bins_x, n_spatial_bins_y, numWords])
		bin_comb = temp[binsx, binsy, binsa]
		hist_temp, _ = histogram(bin_comb, bins=range(number_of_bins+1), density=True)
		hist.append(hist_temp)
	
	hist = hstack(hist)
	hist = array(hist, 'float32') / sum(hist)
	return hist

def read_unclustered_data(filename, num_clusters, cl_type="kMeans"):
    """Return dictionary of cluster id to array of points.

    Given a filename in the format of lat, lng
    generate k clusters based on arguments. Outputs a dictionary with
    the cluster id as the key mapped to a list of lat, lng pts
    """
    request_points = []
    with open(filename, 'rb') as input_file:
        input_file.next()  # Skip the header row
        for line in input_file:
            lat, lng = line.split(',')
            request_points.append((float(lat), float(lng)))
    request_points = array(request_points)

    if cl_type == "kMeans":
        # computing K-Means with K = num_clusters
        centroids, _ = kmeans(request_points, int(num_clusters))
        # assign each sample to a cluster
        idx, _ = vq(request_points, centroids)

    else:
        # computeing kMedoids using distance matrix
        centroids = get_kmedoids(request_points, int(num_clusters))
        # assign each sample to a cluster
        idx, _ = vq(request_points, centroids)

    # map cluster lat, lng to cluster index
    cluster_points = defaultdict(list)
    for i in xrange(len(request_points)):
        lat, lng = request_points[i]
        cluster_points[idx[i]].append((lat, lng))
    return cluster_points

def bic_kmeans(features, **kwargs):
    '''
    Run kmeans on features with **kwargs given to scipy.cluster.vq.kmeans for
    different numbers of clusters, k.  Choose, finally, the clustering that
    minimizes the Beysian Information Criterion or BIC.
    '''
    max_k = int(2*numpy.log(len(features)))

    base_distances = vq(features, 
            numpy.array([numpy.average(features, axis=0)]))[1]
    base_std = numpy.std(base_distances)

    centers_list = []
    bic_list = []
    distances_list = []
    for k in range(1, max_k+1):
        centers = kmeans(features, k, **kwargs)[0]
        clusters, distances = vq(features, centers)
        bic = calculate_bic(clusters, distances, base_std)
        centers_list.append(centers)
        distances_list.append(distances)
        bic_list.append(bic)

    best_index = numpy.argmin(bic_list)
    return centers_list[best_index], distances_list[best_index]

def _get_larger_chroms(ref_file):
    """Retrieve larger chromosomes, avoiding the smaller ones for plotting.
    """
    from scipy.cluster.vq import kmeans, vq
    all_sizes = []
    for c in ref.file_contigs(ref_file):
        all_sizes.append(float(c.size))
    all_sizes.sort()
    # separate out smaller chromosomes and haplotypes with kmeans
    centroids, _ = kmeans(np.array(all_sizes), 2)
    idx, _ = vq(np.array(all_sizes), centroids)
    little_sizes = tz.first(tz.partitionby(lambda xs: xs[0], zip(idx, all_sizes)))
    little_sizes = [x[1] for x in little_sizes]
    # create one more cluster with the smaller, removing the haplotypes
    centroids2, _ = kmeans(np.array(little_sizes), 2)
    idx2, _ = vq(np.array(little_sizes), centroids2)
    little_sizes2 = tz.first(tz.partitionby(lambda xs: xs[0], zip(idx2, little_sizes)))
    little_sizes2 = [x[1] for x in little_sizes2]
    # get any chromosomes not in haplotype/random bin
    thresh = max(little_sizes2)
    larger_chroms = []
    for c in ref.file_contigs(ref_file):
        if c.size > thresh:
            larger_chroms.append(c.name)
    return larger_chroms

 def run(self, features, number_of_clusters='3', restarts=10):
     if number_of_clusters != 'Use BIC':
         k = int(number_of_clusters)
         if k == 1:
             result = numpy.zeros(len(features), dtype=numpy.int32)
             return [result]
         return [vq(features, kmeans(features, k, iter=restarts)[0])[0]]
     else:
         return [vq(features, bic_kmeans(features, iter=restarts)[0])[0]]

def sphere_tissue_image(size=100, n_points=12):

    center = np.array([size/2,size/2,size/2],float)
    radius = size/4.

    points = {}
    for p in range(n_points):
        theta = np.random.rand()*2.*np.pi
        phi = np.random.rand()*np.pi - np.pi/2.
        
        points[p+3] = center + radius*np.array([np.cos(theta)*np.cos(phi),np.sin(theta)*np.cos(phi),np.sin(phi)])
    points = array_dict(points)

    point_target_area = 4.*np.pi*np.power(radius,2.)/float(n_points)
    point_target_distance = np.power(point_target_area/np.pi,0.5)

    sigma_deformation = (size/100.)*(20./n_points)
    omega_forces = dict(distance=0.1*size/100., repulsion=100.0*np.power(size/100.,2))

    for iterations in xrange(100):
        point_vectors = np.array([points[p]- points.values() for p in points.keys()])
        point_distances = np.array([vq(points.values(),np.array([points[p]]))[1] for p in points.keys()])
        point_vectors = point_vectors/(point_distances[...,np.newaxis]+1e-7)

        point_distance_forces = omega_forces['distance']*((point_distances-point_target_distance)[...,np.newaxis]*point_vectors/point_target_distance).sum(axis=1)
        
        point_repulsion_forces = omega_forces['repulsion']*np.power(point_target_distance,2)*(point_vectors/(np.power(point_distances,2)+1e-7)[...,np.newaxis]).sum(axis=1)
        
        point_forces = np.zeros((len(points),3))
        point_forces += point_distance_forces
        point_forces += point_repulsion_forces
        
        point_forces = np.minimum(1.0,sigma_deformation/np.linalg.norm(point_forces,axis=1))[:,np.newaxis] * point_forces
        
        new_points = points.values() + point_forces
        
        new_points = center+ radius*((new_points-center)/np.linalg.norm((new_points-center),axis=1)[:,np.newaxis])
        
        points = array_dict(new_points,points.keys())
    points[2] = center

    coords = np.transpose(np.mgrid[0:size,0:size,0:size],(1,2,3,0)).reshape((np.power(size,3),3)).astype(int)
    labels = points.keys()[vq(coords,points.values())[0]]

    ext_coords = coords[vq(coords,np.array([center]))[1]>size/3.]

    img = np.ones((size,size,size),np.uint8)
    img[tuple(np.transpose(coords))] = labels
    img[tuple(np.transpose(ext_coords))] = 1
    img = SpatialImage(img,resolution=(60./size,60./size,60./size))

    return img

def performance_measure(reference_set,experimental_set,measure='jaccard_index'):
    VP = (vq(experimental_set,reference_set)[1]==0).sum()
    FP = (vq(experimental_set,reference_set)[1]>0).sum()
    FN = (vq(reference_set,experimental_set)[1]>0).sum()

    if measure == 'true_positive':
        return VP
    elif measure == 'precision':
        return VP/float(VP+FP) 
    elif measure == 'recall':
        return VP/float(VP+FN) 
    elif measure == 'dice_index':
        return 2*VP / float(2*VP+FP+FN)
    elif measure == 'jaccard_index':
        return VP/float(VP+FP+FN)

def vectorQuantization (features, bits, debug=False):
	from scipy.cluster.vq import vq
	D = len(features[0])
	np_features = np.array(features)
	nom_features = np.empty(np_features.shape, dtype=str)
	for i in range(D):
		column = np_features[:,i]
		max_val = np.max(column)
		min_val = np.min(column)
		bits = bits
		denom = bits
		step = (max_val - min_val)/denom
		partition = [0]*(denom+1)
		codebook = [0]*(denom+1)
		for j in range(denom+1):
			partition[j] = (min_val+(step*j))
			codebook[j] = j
		column = np.array(column)
		partition = np.array(partition)
		if debug:
			print('****')
			print(column)
			print(partition)
		tmp = vq(column,partition)
		nom_col = [str(int(x)+1) for x in tmp[0]]
		if debug:
			print tmp[0]
			print nom_col
			print '****'
		nom_features[:,i] = nom_col
	return nom_features

def classify_kmeans(infile, clusternumber):
    '''
    apply kmeans
    '''
    
    #Load infile in data array    
    driver = gdal.GetDriverByName('GTiff')
    driver.Register()
    ds = gdal.Open(infile, gdal.GA_Update)
    databand = ds.GetRasterBand(1)
    
    #Read input raster into array
    data = ds.ReadAsArray() 
    #replace no data value with numpy.nan
    #data[data==-999.0]=numpy.nan 
    
    pixel = numpy.reshape(data,(data.shape[0]*data.shape[1]))
    centroids, variance = kmeans(pixel, clusternumber)
    code, distance = vq(pixel,centroids)
    centers_idx = numpy.reshape(code,(data.shape[0],data.shape[1]))
    clustered = centroids[centers_idx]
    
    # Write outraster to file
    databand.WriteArray(clustered)
    databand.FlushCache()        
    
    #Close file
    databand = None
    clustered = None
    ds = None  

def select(file, output, clusters=None):
    """
    Select clusters containing real motifs and discard the rest

    Parameters
    ----------
    file : An hdf5 file containing clustered motif matches as generated by birdwerdz.hdf.classify
    output : Name of output file which will contain only motifs from selected
             clusters.  If same as input file, will delete motifs from the file
    clusters : Clusters to select 

    """
    if file == output:
        mode = 'r+'
    else:
        mode = 'w-'
    with h5py.File(output, mode) as out:
        if file != output:
            with h5py.File(file, 'r+') as src:
                for entry in src.values():
                    out['/'].copy(entry,entry.name)
        for entry in out.values():
            if not isinstance(entry,h5py.Group) or 'motifs' not in entry.keys():
                continue

            amp_vecs= entry['motifs']['spectrogram'].sum(1) 

            cluster_path = 'cluster_mean_spectrograms'
            id,_ = vq(amp_vecs, out[cluster_path][:].sum(1))

            new_motifs=np.delete(entry['motifs'], np.where(
                [i not in clusters for i in id])[0])

            del entry['motifs']
            entry.create_dataset('motifs',data=new_motifs)

def clustering2(img,clusters):
    "another clustering method - no major differences"
    #Reshaping image in list of pixels to allow kmean Algorithm
    #From 1792x1792x3 to 1792^2x3
    pixels = np.reshape(img,(img.shape[0]*img.shape[1],3))
    centroids,_ = kmeans2(pixels,3,iter=3,minit= 'random')
    #print ("Centroids : ",centroids.dtype,centroids.shape,type(centroids))
    #print centroids
    # quantization
    #Assigns a code from a code book to each observation
    #code : A length N array holding the code book index for each observation.
    #dist : The distortion (distance) between the observation and its nearest code.
    code,_ = vq(pixels,centroids)
    #print ("Code : ",code.dtype,code.shape,type(code))
    #print code

    # reshaping the result of the quantization
    reshaped = np.reshape(code,(img.shape[0],img.shape[1]))
    #print ("reshaped : ",reshaped.dtype,reshaped.shape,type(reshaped))

    clustered = centroids[reshaped]
    #print ("clustered : ",clustered.dtype,clustered.shape,type(clustered))
    
    #scatter3D(centroids)
    return clustered

def clustering_scipy_kmeans(features, n_clust = 8):
  """
  """
  whitened = whiten(features)
  print whitened.shape
  
  initial = [kmeans(whitened,i) for i in np.arange(1,12)]
  plt.plot([var for (cent,var) in initial])
  plt.show()
  
  #cent, var = initial[3]
  ##use vq() to get as assignment for each obs.
  #assignment,cdist = vq(whitened,cent)
  #plt.scatter(whitened[:,0], whitened[:,1], c=assignment)
  #plt.show()
  
  codebook, distortion = kmeans(whitened, n_clust)
  print codebook, distortion
  assigned_label, dist = vq(whitened, codebook)
  for ii in range(8):
    plt.subplot(4,2,ii+1)
    plt.plot(codebook[ii])
  plt.show()
  
  centroid, label = kmeans2(whitened, n_clust, minit = 'points')
  print centroid, label
  for ii in range(8):
    plt.subplot(4,2,ii)
    plt.plot(centroid[ii])
  plt.show()

def kmeans(features, projection, ite = 50, k = 4, threshold = 1e-5):    
    """ perform k_keamns clustering and return a the result as a subsapce clustering object """
    from scipy.cluster.vq import kmeans, vq
    import datetime

    from measures import spatial_coherence    
   
    centroids, distance = kmeans(features, k, iter=ite, thresh=threshold)
    code, _ = vq(features, centroids)
    
    run_ = datetime.datetime.now().strftime("%y_%m_%d_%H_%M")
    
    params = "projection_size=%d, k=%d" %(len(projection), k)
    clusters = clusters_from_code(code, k, projection)
  
    clustering_id = "(%s)_(%s)_(%s)_(%s)" %("exhaustive_kmeans", params, run_, projection)
    #print clustering_id
    km_clt = KMClustering(algorithm ="exhaustive_kmeans", parameters = params, run = run_,
                          clustering_id = clustering_id, clusters = clusters, ccontains_noise = False, cclustering_on_dimension = True)

   
    measures = {'spatial_coherence': spatial_coherence(km_clt, len(features))[0], 'distortion': distance}
    km_clt.update_measures(measures)
    
    return  km_clt 

def new_labelled_page(no_of_samples:int, window_size:int, page_scale:int or tuple, labelled_centroids:[tuple], page_paths:[str]):
    ### Duplication from above
    weighter = gaussian_weighter(window_size)
    windower = f.partial(win_centred_on, window=window_size)
    shifter = f.partial(point_shift, window=window_size)
    scaler = img_scaler(page_scale)
    make_observations = compose(prepare_features, real_fft)
    img, label = open_image_label(*page_paths)
    img, label = scaler(img, label)
    f_img = prepare_fft_image(img, window_size)
    access_img = img_accessor(img, identity)
    access_label = img_accessor(label, identity)
    access_f_img = img_accessor(f_img, compose(windower, shifter))
    ### End of duplication
    labels = [a[0] for a in labelled_centroids]
    centroids = np.asarray([a[1] for a in labelled_centroids])
    new_label = np.zeros_like(label)
    for s in img_slices(new_label.shape, 80):
        unlabelled_samples = sample_all_in_area(s, applier(identity, compose(make_observations, access_f_img)))   
        coords = [a[0] for a in unlabelled_samples]
        observations = np.asarray([a[1] for a in unlabelled_samples])
        codes, dist = vq.vq(observations, centroids)
        for i, code in zip(coords, codes):
            new_label[i] = labels[code]
    return new_label