Python torch.from_numpy() Examples

def plot_wh_methods():  # from utils.utils import *; plot_wh_methods()
    # Compares the two methods for width-height anchor multiplication
    # https://github.com/ultralytics/yolov3/issues/168
    x = np.arange(-4.0, 4.0, .1)
    ya = np.exp(x)
    yb = torch.sigmoid(torch.from_numpy(x)).numpy() * 2

    fig = plt.figure(figsize=(6, 3), dpi=150)
    plt.plot(x, ya, '.-', label='yolo method')
    plt.plot(x, yb ** 2, '.-', label='^2 power method')
    plt.plot(x, yb ** 2.5, '.-', label='^2.5 power method')
    plt.xlim(left=-4, right=4)
    plt.ylim(bottom=0, top=6)
    plt.xlabel('input')
    plt.ylabel('output')
    plt.legend()
    fig.tight_layout()
    fig.savefig('comparison.png', dpi=200) 

def __init__(self, T, opts):
        super(LOOLoss, self).__init__()
        
        self.gpu = opts.gpu
        self.loo = opts.loo if 'LOO' in opts.method else 0.
        self.label_smooth = opts.label_smooth
        self.kld_u_const = math.log(len(T['wnids']))
        self.relevant = [torch.from_numpy(rel) for rel in T['relevant']]
        self.labels_relevant = torch.from_numpy(T['labels_relevant'].astype(np.uint8))
        ch_slice = T['ch_slice']
        if opts.class_wise:
            num_children = T['num_children']
            num_supers = len(num_children)
            self.class_weight = torch.zeros(ch_slice[-1])
            for m, num_ch in enumerate(num_children):
                self.class_weight[ch_slice[m]:ch_slice[m+1]] = 1. / (num_ch * num_supers)
        else:
            self.class_weight = torch.ones(ch_slice[-1]) / ch_slice[-1] 

def __call__(self, img):
        """Convert a ``numpy.ndarray`` to tensor.

        Args:
            img (numpy.ndarray): Image to be converted to tensor.

        Returns:
            Tensor: Converted image.
        """
        if not(_is_numpy_image(img)):
            raise TypeError('img should be ndarray. Got {}'.format(type(img)))

        if isinstance(img, np.ndarray):
            # handle numpy array
            if img.ndim == 3:
                img = torch.from_numpy(img.transpose((2, 0, 1)).copy())
            elif img.ndim == 2:
                img = torch.from_numpy(img.copy())
            else:
                raise RuntimeError('img should be ndarray with 2 or 3 dimensions. Got {}'.format(img.ndim))

            # backward compatibility
            #return img.float().div(255)
            return img.float() 

def __getitem__(self, index):

        img=self.adv_flat[self.sample_num,:]

        if(self.shuff == False):
            # shuff is true for non-pgd attacks
            img = torch.from_numpy(np.reshape(img,(3,224,224)))
        else:
            img = torch.from_numpy(img).type(torch.FloatTensor)
        target = self.adv_dict["adv_labels"][self.sample_num]
        # doing this so that it is consistent with all other datasets
        # to return a PIL Image
        if self.transform is not None:
            img = self.transform(img)

        if self.target_transform is not None:
            target = self.target_transform(target)

        self.sample_num = self.sample_num + 1
        return img, target 

def _get_area_ratio(self, pos_proposals, pos_assigned_gt_inds, gt_masks):
        """Compute area ratio of the gt mask inside the proposal and the gt
        mask of the corresponding instance."""
        num_pos = pos_proposals.size(0)
        if num_pos > 0:
            area_ratios = []
            proposals_np = pos_proposals.cpu().numpy()
            pos_assigned_gt_inds = pos_assigned_gt_inds.cpu().numpy()
            # compute mask areas of gt instances (batch processing for speedup)
            gt_instance_mask_area = gt_masks.areas
            for i in range(num_pos):
                gt_mask = gt_masks[pos_assigned_gt_inds[i]]

                # crop the gt mask inside the proposal
                bbox = proposals_np[i, :].astype(np.int32)
                gt_mask_in_proposal = gt_mask.crop(bbox)

                ratio = gt_mask_in_proposal.areas[0] / (
                    gt_instance_mask_area[pos_assigned_gt_inds[i]] + 1e-7)
                area_ratios.append(ratio)
            area_ratios = torch.from_numpy(np.stack(area_ratios)).float().to(
                pos_proposals.device)
        else:
            area_ratios = pos_proposals.new_zeros((0, ))
        return area_ratios 

def __getitem__(self, index):

        img=self.adv_flat[self.sample_num,:]

        if(self.shuff == False):
            # shuff is true for non-pgd attacks
            img = torch.from_numpy(np.reshape(img,(3,32,32)))
        else:
            img = torch.from_numpy(img).type(torch.FloatTensor)
        target = np.argmax(self.adv_dict["adv_labels"],axis=1)[self.sample_num]
        # doing this so that it is consistent with all other datasets
        # to return a PIL Image
        if self.transform is not None:
            img = self.transform(img)

        if self.target_transform is not None:
            target = self.target_transform(target)

        self.sample_num = self.sample_num + 1
        return img, target 

def __getitem__(self, index):

        img=self.adv_flat[self.sample_num,:]

        if(self.shuff == False):
            # shuff is true for non-pgd attacks
            img = torch.from_numpy(np.reshape(img,(3,32,32)))
        else:
            img = torch.from_numpy(img).type(torch.FloatTensor)
        target = np.argmax(self.adv_dict["adv_labels"],axis=1)[self.sample_num]
        # doing this so that it is consistent with all other datasets
        # to return a PIL Image
        if self.transform is not None:
            img = self.transform(img)

        if self.target_transform is not None:
            target = self.target_transform(target)

        self.sample_num = self.sample_num + 1
        return img, target 

def __getitem__(self, index):
        img=self.adv_flat[self.sample_num,:]
        if(self.transp == False):
            # shuff is true for non-pgd attacks
            img = torch.from_numpy(np.reshape(img,(28,28)))
        else:
            img = torch.from_numpy(img).type(torch.FloatTensor)
        target = np.argmax(self.adv_dict["adv_labels"],axis=1)[self.sample_num]
        # doing this so that it is consistent with all other datasets
        # to return a PIL Image

        if self.transform is not None:
            img = self.transform(img)
        if self.target_transform is not None:
            target = self.target_transform(target)
        self.sample_num = self.sample_num + 1
        return img, target 

def _zeros_embed(self, embed_dict, words_dict):
        """
        :param embed_dict:
        :param words_dict:
        """
        print("loading pre_train embedding by zeros for out of vocabulary.")
        embeddings = np.zeros((int(self.words_count), int(self.dim)))
        for word in words_dict:
            if word in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word]], dtype='float32')
                self.exact_count += 1
            elif word.lower() in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word.lower()]], dtype='float32')
                self.fuzzy_count += 1
            else:
                self.oov_count += 1
        final_embed = torch.from_numpy(embeddings).float()
        return final_embed 

def _nn_embed(self, embed_dict, words_dict):
        """
        :param embed_dict:
        :param words_dict:
        """
        print("loading pre_train embedding by nn.Embedding for out of vocabulary.")
        embed = nn.Embedding(int(self.words_count), int(self.dim))
        init.xavier_uniform_(embed.weight.data)
        embeddings = np.array(embed.weight.data)
        for word in words_dict:
            if word in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word]], dtype='float32')
                self.exact_count += 1
            elif word.lower() in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word.lower()]], dtype='float32')
                self.fuzzy_count += 1
            else:
                self.oov_count += 1
        embeddings[self.padID] = 0
        final_embed = torch.from_numpy(embeddings).float()
        return final_embed 

def _uniform_embed(self, embed_dict, words_dict):
        """
        :param embed_dict:
        :param words_dict:
        """
        print("loading pre_train embedding by uniform for out of vocabulary.")
        embeddings = np.zeros((int(self.words_count), int(self.dim)))
        inword_list = {}
        for word in words_dict:
            if word in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word]], dtype='float32')
                inword_list[words_dict[word]] = 1
                self.exact_count += 1
            elif word.lower() in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word.lower()]], dtype='float32')
                inword_list[words_dict[word]] = 1
                self.fuzzy_count += 1
            else:
                self.oov_count += 1
        uniform_col = np.random.uniform(-0.25, 0.25, int(self.dim)).round(6)  # uniform
        for i in range(len(words_dict)):
            if i not in inword_list and i != self.padID:
                embeddings[i] = uniform_col
        final_embed = torch.from_numpy(embeddings).float()
        return final_embed 

def _avg_embed(self, embed_dict, words_dict):
        """
        :param embed_dict:
        :param words_dict:
        """
        print("loading pre_train embedding by avg for out of vocabulary.")
        embeddings = np.zeros((int(self.words_count), int(self.dim)))
        inword_list = {}
        for word in words_dict:
            if word in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word]], dtype='float32')
                inword_list[words_dict[word]] = 1
                self.exact_count += 1
            elif word.lower() in embed_dict:
                embeddings[words_dict[word]] = np.array([float(i) for i in embed_dict[word.lower()]], dtype='float32')
                inword_list[words_dict[word]] = 1
                self.fuzzy_count += 1
            else:
                self.oov_count += 1
        sum_col = np.sum(embeddings, axis=0) / len(inword_list)  # avg
        for i in range(len(words_dict)):
            if i not in inword_list and i != self.padID:
                embeddings[i] = sum_col
        final_embed = torch.from_numpy(embeddings).float()
        return final_embed 

def get_eval_data(text, wav_path):
    '''
    get data for eval
    --------------
    input:
        text --- pinyin format sequence
    output:
        text --- [1, T_x]
        mel ---  [1, 1, n_mels]
    '''
    text = text_normalize(text) + 'E'
    text = [hp.char2idx[c] for c in text]
    text = torch.Tensor(text).type(torch.LongTensor)  # [T_x]
    text = text.unsqueeze(0)  # [1, T_x]
    mel = torch.zeros(1, 1, hp.n_mels)  # GO frame [1, 1, n_mels]

    _, ref_mels, _ = load_spectrograms(wav_path)
    ref_mels = torch.from_numpy(ref_mels).unsqueeze(0)

    return text, mel, ref_mels 

def get_screen(self, env):
        screen = env.render(mode='rgb_array').transpose((2, 0, 1))  # transpose into torch order (CHW)
        # Strip off the top and bottom of the screen
        screen = screen[:, 160:320]
        view_width = 320
        cart_location = self.get_cart_location(env)
        if cart_location < view_width // 2:
            slice_range = slice(view_width)
        elif cart_location > (self.screen_width - view_width // 2):
            slice_range = slice(-view_width, None)
        else:
            slice_range = slice(cart_location - view_width // 2,
                                cart_location + view_width // 2)
        # Strip off the edges, so that we have a square image centered on a cart
        screen = screen[:, :, slice_range]
        # Convert to float, rescale, convert to torch tensor
        screen = np.ascontiguousarray(screen, dtype=np.float32) / 255
        screen = torch.from_numpy(screen)
        # Resize, and add a batch dimension (BCHW)
        return resize(screen).unsqueeze(0) 

def prune_model_keep_size(model, prune_idx, CBL_idx, CBLidx2mask):

    pruned_model = deepcopy(model)
    for idx in prune_idx:
        mask = torch.from_numpy(CBLidx2mask[idx]).cuda()
        bn_module = pruned_model.module_list[idx][1]

        bn_module.weight.data.mul_(mask)

        activation = F.leaky_relu((1 - mask) * bn_module.bias.data, 0.1)

        # 两个上采样层前的卷积层
        next_idx_list = [idx + 1]
        if idx == 79:
            next_idx_list.append(84)
        elif idx == 91:
            next_idx_list.append(96)

        for next_idx in next_idx_list:
            next_conv = pruned_model.module_list[next_idx][0]
            conv_sum = next_conv.weight.data.sum(dim=(2, 3))
            offset = conv_sum.matmul(activation.reshape(-1, 1)).reshape(-1)
            if next_idx in CBL_idx:
                next_bn = pruned_model.module_list[next_idx][1]
                next_bn.running_mean.data.sub_(offset)
            else:
                next_conv.bias.data.add_(offset)

        bn_module.bias.data.mul_(mask)

    return pruned_model 

def decode_seg_map_sequence(label_masks, dataset='pascal'):
    rgb_masks = []
    for label_mask in label_masks:
        rgb_mask = decode_segmap(label_mask, dataset)
        rgb_masks.append(rgb_mask)
    rgb_masks = torch.from_numpy(np.array(rgb_masks).transpose([0, 3, 1, 2]))
    return rgb_masks 

def cross_entropy2d(logit, target, ignore_index=255, weight=None, size_average=True, batch_average=True):
    """
    logit 是网络输出 (batchsize, 21, 512, 512) 值应该为任意(没经历归一化)
    target是gt      (batchsize,  1, 512, 512) 值应该是背景为0，其他类分别为1-20，忽略为255
    return 经过h*w*batchsize平均的loss
    这里的loss相当于对每个像素点求分类交叉熵
    ignore_index 是指target中有些忽略的(非背景也非目标，是不属于数据集类别的其他物体，不计算loss) 表现为白色
    最后要注意：crossentropy是已经经过softmax，所以网络最后一层不需要处理
    https://pytorch.org/docs/stable/nn.html#torch.nn.CrossEntropyLoss
    """
    n, c, h, w = logit.size()
    # logit = logit.permute(0, 2, 3, 1)
    target = target.squeeze(1)# (batchsize, 1, 512, 512) -> (batchsize, 512, 512)
    if weight is None:
        criterion = nn.CrossEntropyLoss(weight=weight, ignore_index=ignore_index, size_average=False)
    else:
        criterion = nn.CrossEntropyLoss(weight=torch.from_numpy(np.array(weight)).float().cuda(), ignore_index=ignore_index, size_average=False)
    loss = criterion(logit, target.long())

    if size_average:
        loss /= (h * w)

    if batch_average:
        loss /= n

    return loss 

def __call__(self, sample):
        # swap color axis because
        # numpy image: H x W x C
        # torch image: C X H X W
        img = np.array(sample['image']).astype(np.float32).transpose((2, 0, 1))
        mask = np.expand_dims(np.array(sample['label']).astype(np.float32), -1).transpose((2, 0, 1))
        mask[mask == 255] = 0

        img = torch.from_numpy(img).float()
        mask = torch.from_numpy(mask).float()

        return {'image': img,
                'label': mask} 

def test_dict_recursive_bypass(self):
        d = {'data': np.array([1]), 'target': {'a': np.array([1]), 'b': np.array([1])}}
        d = dict_recursive_bypass(d, lambda v: torch.from_numpy(v))

        self.assertTrue(isinstance(d['data'], Tensor))
        self.assertTrue(isinstance(d['target']['a'], Tensor))
        self.assertTrue(isinstance(d['target']['b'], Tensor)) 

def augmentate_and_to_pytorch(item: {}):
    res = augmentate(item)
    return {'data': torch.from_numpy(np.moveaxis(res['data'].astype(np.float32) / 255., -1, 0)),
            'target': torch.from_numpy(np.expand_dims(res['target'].astype(np.float32) / 255, axis=0))} 

def load_word_embedding(vse):
    checkpoint = torch.load(vse)
    opt = checkpoint['opt']
    vocab = Vocab.from_pickle(pjoin(opt.vocab_path, '%s_vocab.pkl' % opt.data_name))

    if not args.glove_only:
        embed_weights = checkpoint['model'][1]['embed.weight'].cpu().numpy()
        _, glove_weights = io.load('data/snli/glove.pkl')
        embed_weights = np.concatenate((glove_weights, embed_weights), axis=1)
    else:
        _, embed_weights = io.load('data/snli/glove.pkl')
    embedding = nn.Embedding(embed_weights.shape[0], embed_weights.shape[1], padding_idx=0)
    embedding.weight.data.copy_(torch.from_numpy(embed_weights))
    return vocab, embedding 

def load_word_embedding(vse):
    checkpoint = torch.load(vse)
    opt = checkpoint['opt']
    vocab = Vocab.from_pickle(pjoin(opt.vocab_path, '%s_vocab.pkl' % opt.data_name))

    if not args.glove_only:
        embed_weights = checkpoint['model'][1]['embed.weight'].cpu().numpy()
        _, glove_weights = io.load('data/snli/glove.pkl')
        embed_weights = np.concatenate((glove_weights, embed_weights), axis=1)
    else:
        _, embed_weights = io.load('data/snli/glove.pkl')
    embedding = nn.Embedding(embed_weights.shape[0], embed_weights.shape[1], padding_idx=0)
    embedding.weight.data.copy_(torch.from_numpy(embed_weights))
    return vocab, embedding 

def _anchor_component(self, height, width):
    # just to get the shape right
    #height = int(math.ceil(self._im_info.data[0, 0] / self._feat_stride[0]))
    #width = int(math.ceil(self._im_info.data[0, 1] / self._feat_stride[0]))
    anchors, anchor_length = generate_anchors_pre(\
                                          height, width,
                                           self._feat_stride, self._anchor_scales, self._anchor_ratios)
    self._anchors = Variable(torch.from_numpy(anchors).cuda())
    self._anchor_length = anchor_length 

def _generate_pseudo_gtbox(self, fuse_prob, boxes): # Inputs are two variables
      #return gt_boxes Variable(torch.from_numpy(gt_boxes).cuda()) size: gt_num * (x1,y1,x2,y2,class)
    gt_boxes, proposals = generate_pseudo_gtbox(boxes, fuse_prob, self._labels)
    return gt_boxes, proposals 

def forward(self, image, im_info, boxes, labels=None, mode='TRAIN'): #done
    self._image_gt_summaries['image'] = image
    self._image_gt_summaries['boxes'] = boxes
    self._image_gt_summaries['im_info'] = im_info
    self._image_gt_summaries['labels'] = labels
    
    self._image = Variable(torch.from_numpy(image.transpose([0,3,1,2])).cuda(), volatile=mode == 'TEST')
    self._im_info = im_info # No need to change; actually it can be an list
    self._boxes = Variable(torch.from_numpy(boxes).type('torch.Tensor').cuda())
    self._labels = Variable(torch.from_numpy(labels).type('torch.Tensor').cuda()) if labels is not None else None


    self._mode = mode
    '''
       (1) do image -> net_conv 
    '''
    torch.backends.cudnn.benchmark = False
    net_conv = self._image_to_head()

    '''
       (2) do net_conv -> faster-branch 
    '''
    cls_prob_fast, bbox_pred_fast = self._predict_fast(net_conv)
    
    

    if mode == 'TEST':
      if 1:
          '''
              (3) do net_conv -> wsddn-branch 
          '''
          fuse_prob = self._predict(net_conv)
      stds = bbox_pred_fast.data.new(cfg.TRAIN.BBOX_NORMALIZE_STDS).repeat(self._num_classes + 1).unsqueeze(0).expand_as(bbox_pred_fast)
      means = bbox_pred_fast.data.new(cfg.TRAIN.BBOX_NORMALIZE_MEANS).repeat(self._num_classes + 1).unsqueeze(0).expand_as(bbox_pred_fast)
      self._predictions["bbox_pred_fast"] = bbox_pred_fast.mul(Variable(stds)).add(Variable(means))
    else:
      self._add_losses() # compute losses 

def _compute_targets(ex_rois, gt_rois):
  """Compute bounding-box regression targets for an image."""

  assert ex_rois.shape[0] == gt_rois.shape[0]
  assert ex_rois.shape[1] == 4
  assert gt_rois.shape[1] == 5

  return bbox_transform(torch.from_numpy(ex_rois), torch.from_numpy(gt_rois[:, :4])).numpy() 

def __call__(self, img):

        if random.uniform(0, 1) > self.EPSILON:
            return img

        for attempt in range(100):
            area = img.size()[1] * img.size()[2]
       
            target_area = random.uniform(self.sl, self.sh) * area
            aspect_ratio = random.uniform(self.r1, 1/self.r1)

            h = int(round(math.sqrt(target_area * aspect_ratio)))
            w = int(round(math.sqrt(target_area / aspect_ratio)))

            if w < img.size()[2] and h < img.size()[1]:
                x1 = random.randint(0, img.size()[1] - h)
                y1 = random.randint(0, img.size()[2] - w)
                if img.size()[0] == 3:
                    #img[0, x1:x1+h, y1:y1+w] = random.uniform(0, 1)
                    #img[1, x1:x1+h, y1:y1+w] = random.uniform(0, 1)
                    #img[2, x1:x1+h, y1:y1+w] = random.uniform(0, 1)
                    img[0, x1:x1+h, y1:y1+w] = self.mean[0]
                    img[1, x1:x1+h, y1:y1+w] = self.mean[1]
                    img[2, x1:x1+h, y1:y1+w] = self.mean[2]
                    #img[:, x1:x1+h, y1:y1+w] = torch.from_numpy(np.random.rand(3, h, w))
                else:
                    img[0, x1:x1+h, y1:y1+w] = self.mean[1]
                    # img[0, x1:x1+h, y1:y1+w] = torch.from_numpy(np.random.rand(1, h, w))
                return img

        return img 

def edit_tensor_in_numpy(input, trafo):
    # Kept in case tensor transformations should be done in numpy rather than pytorch (might be slightly faster, but is ugly and might break code..)
    is_cuda = input.is_cuda
    if is_cuda:
        input_np = input.cpu().data.numpy()
    else:
        input_np = input.data.numpy()
    del input
    input_np = trafo(input_np)
    input = Variable(torch.from_numpy(input_np))
    if is_cuda:
        input = input.cuda()
    return input 

def pth_nms(dets, thresh):
  """
  dets has to be a tensor
  """
  if not dets.is_cuda:
    x1 = dets[:, 0]
    y1 = dets[:, 1]
    x2 = dets[:, 2]
    y2 = dets[:, 3]
    scores = dets[:, 4]

    areas = (x2 - x1 + 1) * (y2 - y1 + 1)
    order = scores.sort(0, descending=True)[1]
    # order = torch.from_numpy(np.ascontiguousarray(scores.numpy().argsort()[::-1])).long()

    keep = torch.LongTensor(dets.size(0))
    num_out = torch.LongTensor(1)
    nms.cpu_nms(keep, num_out, dets, order, areas, thresh)

    return keep[:num_out[0]]
  else:
    x1 = dets[:, 0]
    y1 = dets[:, 1]
    x2 = dets[:, 2]
    y2 = dets[:, 3]
    scores = dets[:, 4]

    areas = (x2 - x1 + 1) * (y2 - y1 + 1)
    order = scores.sort(0, descending=True)[1]
    # order = torch.from_numpy(np.ascontiguousarray(scores.cpu().numpy().argsort()[::-1])).long().cuda()

    dets = dets[order].contiguous()

    keep = torch.LongTensor(dets.size(0))
    num_out = torch.LongTensor(1)
    # keep = torch.cuda.LongTensor(dets.size(0))
    # num_out = torch.cuda.LongTensor(1)
    nms.gpu_nms(keep, num_out, dets, thresh)

    return order[keep[:num_out[0]].cuda()].contiguous()
    # return order[keep[:num_out[0]]].contiguous() 

def collate_fn_BEV(data):
    data2stack=np.stack([d[0] for d in data]).astype(np.float32)
    label2stack=np.stack([d[1] for d in data])
    grid_ind_stack = [d[2] for d in data]
    point_label = [d[3] for d in data]
    xyz = [d[4] for d in data]
    return torch.from_numpy(data2stack),torch.from_numpy(label2stack),grid_ind_stack,point_label,xyz