检查Flux.jl模型中的参数总数？

Question

我知道，使用flux.jl，我可以做

julia> Flux.params(model)

来获取参数，但是输出并未告诉我模型本身中实际存在多少个总参数。是否可以检查此功能或一种计算此方法的方法？

Answer 1

是@mcabbott在评论中提到的，您可以将整个模型传递给参数函数以获取总数（

sum(length, params(model))

）或循环通过每一层，如下所示：

julia> model = Chain(
         resnet[1:end-2],
         Dense(2048, 1000),  
         Dense(1000, 256),
         Dense(256, 2),        # we get 2048 features out, and we have 2 classes
       )
Chain(Chain(Conv((7, 7), 3=>64), MaxPool((3, 3), pad=1, stride=2), Metalhead.ResidualBlock((Conv((1, 1), 64=>64), Conv((3, 3), 64=>64), Conv((1, 1), 64=>256)), (BatchNorm(64), BatchNorm(64), BatchNorm(256)), Chain(Conv((1, 1), 64=>256), BatchNorm(256))), Metalhead.ResidualBlock((Conv((1, 1), 256=>64), Conv((3, 3), 64=>64), Conv((1, 1), 64=>256)), (BatchNorm(64), BatchNorm(64), BatchNorm(256)), identity), Metalhead.ResidualBlock((Conv((1, 1), 256=>64), Conv((3, 3), 64=>64), Conv((1, 1), 64=>256)), (BatchNorm(64), BatchNorm(64), BatchNorm(256)), identity), Metalhead.ResidualBlock((Conv((1, 1), 256=>128), Conv((3, 3), 128=>128), Conv((1, 1), 128=>512)), (BatchNorm(128), BatchNorm(128), BatchNorm(512)), Chain(Conv((1, 1), 256=>512), BatchNorm(512))), Metalhead.ResidualBlock((Conv((1, 1), 512=>128), Conv((3, 3), 128=>128), Conv((1, 1), 128=>512)), (BatchNorm(128), BatchNorm(128), BatchNorm(512)), identity), Metalhead.ResidualBlock((Conv((1, 1), 512=>128), Conv((3, 3), 128=>128), Conv((1, 1), 128=>512)), (BatchNorm(128), BatchNorm(128), BatchNorm(512)), identity), Metalhead.ResidualBlock((Conv((1, 1), 512=>128), Conv((3, 3), 128=>128), Conv((1, 1), 128=>512)), (BatchNorm(128), BatchNorm(128), BatchNorm(512)), identity), Metalhead.ResidualBlock((Conv((1, 1), 512=>256), Conv((3, 3), 256=>256), Conv((1, 1), 256=>1024)), (BatchNorm(256), BatchNorm(256), BatchNorm(1024)), Chain(Conv((1, 1), 512=>1024), BatchNorm(1024))), Metalhead.ResidualBlock((Conv((1, 1), 1024=>256), Conv((3, 3), 256=>256), Conv((1, 1), 256=>1024)), (BatchNorm(256), BatchNorm(256), BatchNorm(1024)), identity), Metalhead.ResidualBlock((Conv((1, 1), 1024=>256), Conv((3, 3), 256=>256), Conv((1, 1), 256=>1024)), (BatchNorm(256), BatchNorm(256), BatchNorm(1024)), identity), Metalhead.ResidualBlock((Conv((1, 1), 1024=>256), Conv((3, 3), 256=>256), Conv((1, 1), 256=>1024)), (BatchNorm(256), BatchNorm(256), BatchNorm(1024)), identity), Metalhead.ResidualBlock((Conv((1, 1), 1024=>256), Conv((3, 3), 256=>256), Conv((1, 1), 256=>1024)), (BatchNorm(256), BatchNorm(256), BatchNorm(1024)), identity), Metalhead.ResidualBlock((Conv((1, 1), 1024=>256), Conv((3, 3), 256=>256), Conv((1, 1), 256=>1024)), (BatchNorm(256), BatchNorm(256), BatchNorm(1024)), identity), Metalhead.ResidualBlock((Conv((1, 1), 1024=>512), Conv((3, 3), 512=>512), Conv((1, 1), 512=>2048)), (BatchNorm(512), BatchNorm(512), BatchNorm(2048)), Chain(Conv((1, 1), 1024=>2048), BatchNorm(2048))), Metalhead.ResidualBlock((Conv((1, 1), 2048=>512), Conv((3, 3), 512=>512), Conv((1, 1), 512=>2048)), (BatchNorm(512), BatchNorm(512), BatchNorm(2048)), identity), Metalhead.ResidualBlock((Conv((1, 1), 2048=>512), Conv((3, 3), 512=>512), Conv((1, 1), 512=>2048)), (BatchNorm(512), BatchNorm(512), BatchNorm(2048)), identity), MeanPool((7, 7)), #103), Dense(2048, 1000), Dense(1000, 256), Dense(256, 2))

julia> paramCount = 0
0

julia> for layer in model
           paramCount += sum(length, params(layer))
       end

julia> paramCount
25840234

在此示例中，我只是在增加计数，但是您可以将计数从每一层附加到一个数组中，以便单独跟踪每个层的计数。

Answer 2

用于磁通0.16，使用

sum(length,Flux.trainables(model))

。