Python numpy 模块，multiply() 实例源码

我们从Python开源项目中，提取了以下50个代码示例，用于说明如何使用numpy.multiply()。

项目：Stein-Variational-Gradient-Descent 作者：DartML | 项目源码 | 文件源码

def svgd_kernel(self, h = -1):
        sq_dist = pdist(self.theta)
        pairwise_dists = squareform(sq_dist)**2
        if h < 0: # if h < 0, using median trick
            h = np.median(pairwise_dists)  
            h = np.sqrt(0.5 * h / np.log(self.theta.shape[0]+1))

        # compute the rbf kernel

        Kxy = np.exp( -pairwise_dists / h**2 / 2)

        dxkxy = -np.matmul(Kxy, self.theta)
        sumkxy = np.sum(Kxy, axis=1)
        for i in range(self.theta.shape[1]):
            dxkxy[:, i] = dxkxy[:,i] + np.multiply(self.theta[:,i],sumkxy)
        dxkxy = dxkxy / (h**2)
        return (Kxy, dxkxy)

项目：esys-pbi 作者：fsxfreak | 项目源码 | 文件源码

def update(self,frame,events):
        falloff = self.falloff

        img = frame.img
        pts = [denormalize(pt['norm_pos'],frame.img.shape[:-1][::-1],flip_y=True) for pt in events.get('gaze_positions',[]) if pt['confidence']>=self.g_pool.min_data_confidence]

        overlay = np.ones(img.shape[:-1],dtype=img.dtype)

        # draw recent gaze postions as black dots on an overlay image.
        for gaze_point in pts:
            try:
                overlay[int(gaze_point[1]),int(gaze_point[0])] = 0
            except:
                pass

        out = cv2.distanceTransform(overlay,cv2.DIST_L2, 5)

        # fix for opencv binding inconsitency
        if type(out)==tuple:
            out = out[0]

        overlay =  1/(out/falloff+1)

        img[:] = np.multiply(img, cv2.cvtColor(overlay,cv2.COLOR_GRAY2RGB), casting="unsafe")

项目：pycpd 作者：siavashk | 项目源码 | 文件源码

def EStep(self):
    P = np.zeros((self.M, self.N))

    for i in range(0, self.M):
      diff     = self.X - np.tile(self.TY[i, :], (self.N, 1))
      diff    = np.multiply(diff, diff)
      P[i, :] = P[i, :] + np.sum(diff, axis=1)

    c = (2 * np.pi * self.sigma2) ** (self.D / 2)
    c = c * self.w / (1 - self.w)
    c = c * self.M / self.N

    P = np.exp(-P / (2 * self.sigma2))
    den = np.sum(P, axis=0)
    den = np.tile(den, (self.M, 1))
    den[den==0] = np.finfo(float).eps

    self.P   = np.divide(P, den)
    self.Pt1 = np.sum(self.P, axis=0)
    self.P1  = np.sum(self.P, axis=1)
    self.Np  = np.sum(self.P1)

项目：NumpyDL 作者：oujago | 项目源码 | 文件源码

def derivative(self, input=None):
        """The derivative of sigmoid is

        .. math:: \\frac{dy}{dx} & = (1-\\varphi(x)) \\otimes \\varphi(x)  \\\\
                  & = \\frac{e^{-x}}{(1+e^{-x})^2} \\\\
                  & = \\frac{e^x}{(1+e^x)^2}

        Returns
        -------
        float32
            The derivative of sigmoid function.
        """
        last_forward = self.forward(input) if input else self.last_forward
        return np.multiply(last_forward, 1 - last_forward)


# sigmoid-end
# tanh-start

项目：Stein-Variational-Gradient-Descent 作者：DartML | 项目源码 | 文件源码

def svgd_kernel(self, theta, h = -1):
        sq_dist = pdist(theta)
        pairwise_dists = squareform(sq_dist)**2
        if h < 0: # if h < 0, using median trick
            h = np.median(pairwise_dists)  
            h = np.sqrt(0.5 * h / np.log(theta.shape[0]+1))

        # compute the rbf kernel
        Kxy = np.exp( -pairwise_dists / h**2 / 2)

        dxkxy = -np.matmul(Kxy, theta)
        sumkxy = np.sum(Kxy, axis=1)
        for i in range(theta.shape[1]):
            dxkxy[:, i] = dxkxy[:,i] + np.multiply(theta[:,i],sumkxy)
        dxkxy = dxkxy / (h**2)
        return (Kxy, dxkxy)

项目：coursera_ML_in_python 作者：whyjay17 | 项目源码 | 文件源码

def gradientDescent(X, y, theta, alpha, iters):
    temp = np.matrix(np.zeros(theta.shape))
    params = int(theta.ravel().shape[1]) #flattens
    cost = np.zeros(iters)

    for i in range(iters):
        err = (X * theta.T) - y

        for j in range(params):
            term = np.multiply(err, X[:,j])
            temp[0, j] = theta[0, j] - ((alpha / len(X)) * np.sum(term))

        theta = temp
        cost[i] = computeCost(X, y, theta)

    return theta, cost

项目：coursera_ML_in_python 作者：whyjay17 | 项目源码 | 文件源码

def computeCost(X, y, theta):
    inner = np.power(((X * theta.T) - y), 2)
    return np.sum(inner) / (2 * len(X))

#def gradientDescent(X, y, theta, alpha, iters):
#    temp = np.matrix(np.zeros(theta.shape))
#    params = int(theta.ravel().shape[1]) #flattens
#    cost = np.zeros(iters)
#
#    for i in range(iters):
#        err = (X * theta.T) - y
#        
#        for j in range(params):
#            term = np.multiply(err, X[:,j])
#            temp[0, j] = theta[0, j] - ((alpha / len(X)) * np.sum(term))
#        
#        theta = temp
#        cost[i] = computeCost(X, y, theta)
#    
#    return theta, cost

项目：photinia 作者：XoriieInpottn | 项目源码 | 文件源码

def _extract_images(filename):
        """???????????????????

        :param filename: ?????
        :return: 4??numpy??[index, y, x, depth]? ???np.float32
        """
        images = []
        print('Extracting {}'.format(filename))
        with gzip.GzipFile(fileobj=open(filename, 'rb')) as f:
            buf = f.read()
            index = 0
            magic, num_images, rows, cols = struct.unpack_from('>IIII', buf, index)
            if magic != 2051:
                raise ValueError('Invalid magic number {} in MNIST image file: {}'.format(magic, filename))
            index += struct.calcsize('>IIII')
            for i in range(num_images):
                img = struct.unpack_from('>784B', buf, index)
                index += struct.calcsize('>784B')
                img = np.array(img, dtype=np.float32)
                # ????[0,255]???[0,1]
                img = np.multiply(img, 1.0 / 255.0)
                img = img.reshape(rows, cols, 1)
                images.append(img)
        return np.array(images, dtype=np.float32)

项目：BlueWhale 作者：caffe2 | 项目源码 | 文件源码

def get_max_q_values(
        self,
        next_states: np.ndarray,
        possible_next_actions: Optional[np.ndarray] = None,
        use_target_network: Optional[bool] = True
    ) -> np.ndarray:
        q_values = self.get_q_values_all_actions(
            next_states, use_target_network
        )

        if possible_next_actions is not None:
            mask = np.multiply(
                np.logical_not(possible_next_actions),
                self.ACTION_NOT_POSSIBLE_VAL
            )
            q_values += mask

        return np.max(q_values, axis=1, keepdims=True)

项目：BlueWhale 作者：caffe2 | 项目源码 | 文件源码

def gen_training_data(
    num_features,
    num_training_samples,
    num_outputs,
    noise_scale=0.1,
):
    np.random.seed(0)
    random.seed(1)
    input_distribution = stats.norm()
    training_inputs = input_distribution.rvs(
        size=(num_training_samples, num_features)
    ).astype(np.float32)
    weights = np.random.normal(size=(num_outputs, num_features)
                              ).astype(np.float32).transpose()
    noise = np.multiply(
        np.random.normal(size=(num_training_samples, num_outputs)), noise_scale
    )
    training_outputs = (np.dot(training_inputs, weights) +
                        noise).astype(np.float32)

    return training_inputs, training_outputs, weights, input_distribution

项目：Flavor-Network 作者：lingcheng99 | 项目源码 | 文件源码

def make_tfidf(arr):
    '''input, numpy array with flavor counts for each recipe and compounds
    return numpy array adjusted as tfidf
    '''
    arr2 = arr.copy()
    N=arr2.shape[0]
    l2_rows = np.sqrt(np.sum(arr2**2, axis=1)).reshape(N, 1)
    l2_rows[l2_rows==0]=1
    arr2_norm = arr2/l2_rows

    arr2_freq = np.sum(arr2_norm>0, axis=0)
    arr2_idf = np.log(float(N+1) / (1.0 + arr2_freq)) + 1.0

    from sklearn.preprocessing import normalize
    tfidf = np.multiply(arr2_norm, arr2_idf)
    tfidf = normalize(tfidf, norm='l2', axis=1)
    print tfidf.shape
    return tfidf

项目：Flavor-Network 作者：lingcheng99 | 项目源码 | 文件源码

def make_tfidf(arr):
    '''input, numpy array with flavor counts for each recipe and compounds
    return numpy array adjusted as tfidf
    '''
    arr2 = arr.copy()
    N=arr2.shape[0]
    l2_rows = np.sqrt(np.sum(arr2**2, axis=1)).reshape(N, 1)
    l2_rows[l2_rows==0]=1
    arr2_norm = arr2/l2_rows

    arr2_freq = np.sum(arr2_norm>0, axis=0)
    arr2_idf = np.log(float(N+1) / (1.0 + arr2_freq)) + 1.0

    from sklearn.preprocessing import normalize
    tfidf = np.multiply(arr2_norm, arr2_idf)
    tfidf = normalize(tfidf, norm='l2', axis=1)
    print tfidf.shape
    return tfidf

项目：OCR 作者：OrangeGuo | 项目源码 | 文件源码

def train(self, training_data_array):
        for data in training_data_array:
            # ??????????
            y1 = np.dot(np.mat(self.theta1), np.mat(data.y0).T)
            sum1 = y1 + np.mat(self.input_layer_bias)
            y1 = self.sigmoid(sum1)

            y2 = np.dot(np.array(self.theta2), y1)
            y2 = np.add(y2, self.hidden_layer_bias)
            y2 = self.sigmoid(y2)

            # ??????????
            actual_vals = [0] * 10
            actual_vals[data.label] = 1
            output_errors = np.mat(actual_vals).T - np.mat(y2)
            hidden_errors = np.multiply(np.dot(np.mat(self.theta2).T, output_errors), self.sigmoid_prime(sum1))

            # ???????????
            self.theta1 += self.LEARNING_RATE * np.dot(np.mat(hidden_errors), np.mat(data.y0))
            self.theta2 += self.LEARNING_RATE * np.dot(np.mat(output_errors), np.mat(y1).T)
            self.hidden_layer_bias += self.LEARNING_RATE * output_errors
            self.input_layer_bias += self.LEARNING_RATE * hidden_errors