N, Len_q, _ = query.shape
N, Len_in, _ = input_flatten.shape
assert (input_spatial_shapes[:, 0] * input_spatial_shapes[:, 1]).sum() == Len_in
value = self.value_proj(input_flatten)
if input_padding_mask is not None:
value = value.masked_fill(input_padding_mask[..., None], float(0))
value = value.view(N, Len_in, self.n_heads, self.d_model // self.n_heads)
sampling_offsets = self.sampling_offsets(query).view(N, Len_q, self.n_heads, self.n_levels, self.n_points, 2)
attention_weights = self.attention_weights(query).view(N, Len_q, self.n_heads, self.n_levels * self.n_points)
attention_weights = F.softmax(attention_weights, -1).view(N, Len_q, self.n_heads, self.n_levels, self.n_points)
# N, Len_q, n_heads, n_levels, n_points, 2
if reference_points.shape[-1] == 2:
offset_normalizer = torch.stack([input_spatial_shapes[..., 1], input_spatial_shapes[..., 0]], -1)
sampling_locations = reference_points[:, :, None, :, None, :] \
+ sampling_offsets / offset_normalizer[None, None, None, :, None, :]
elif reference_points.shape[-1] == 4:
sampling_locations = reference_points[:, :, None, :, None, :2] \
+ sampling_offsets / self.n_points * reference_points[:, :, None, :, None, 2:] * 0.5
else:
raise ValueError(
'Last dim of reference_points must be 2 or 4, but get {} instead.'.format(reference_points.shape[-1]))
output = MSDeformAttnFunction.apply(
value, input_spatial_shapes, input_level_start_index, sampling_locations, attention_weights, self.im2col_step)
output = self.output_proj(output)
return output
如上是可变形注意力的前传函数,请问下怎么可视化attention_weights形成如下效果,这个和detr好像不同
你好,很高兴能够帮助你解决可变形注意力可视化的问题。根据你的描述,我可以提供以下解决方案:
安装所需库:首先,你需要安装matplotlib库以展示热图。你也可以考虑安装seaborn库,它提供了更强大的可视化功能。你可以在命令行中输入以下命令:pip install matplotlib seaborn
提取attention_weights:为了展示热图,你需要先提取attention weights。通常,你的可变形注意力实现会返回一个[batch_size, num_heads, sequence_length, sequence_length]的张量,其中每个数字表示从第i个位置输出时,第j个位置的权重。
可视化热图:接下来,你可以通过将attention_weights绘制成热图来可视化它们。你可以使用matplotlib的imshow函数来实现绘图。代码如下:
import matplotlib.pyplot as plt
def plot_attention_weights(attention_weights):
fig = plt.figure(figsize=(10, 10))
ax = fig.add_subplot(1, 1, 1)
ax.matshow(attention_weights, cmap='viridis')
ax.set_xticklabels([''] + sentence, fontdict={'fontsize': 14}, rotation=90)
ax.set_yticklabels([''] + sentence, fontdict={'fontsize': 14})
plt.show()
这里,我们使用了matshow函数将数据映射为热图。注意,为了使x轴和y轴标签对齐,我们需要手动设置一个空标签。
这里,我们使用了一个4x4的矩阵作为attention_weights。颜色越深表示权重越高。
希望这个解决方案能够帮助你实现所需的可视化效果。若有疑问,请随时与我联系。
请问这个可视化做出来了吗