Modification of multibox-The operation is applied on Conv4-3

[astorfi]

The first execution of 3x3 convolution filters on the feature map (classify and predict the offset to the default boxes) is applied on Conv4-3 layer which is the 21th element of the vgg list defined by the code. I think, it has been defined 24 by misatke. The 24th element of the vgg list is the Conv5-1 layer of the vgg architecture.

[ASoleimaniB]

I think while it should be [21, -2], it does not change any important thing. At the place you edited the code, they just define the details of loc_layers and conf_layers, and this details is similar if we use 21 or 24, because both 21 and 24 have the same size.
However, in forward function (def forward(self, x)), they apply loc_layer and cong layer at the right place which is conv4_3, vgg[22] after relu.
All in all, your suggestion is OK

[amdegroot]

Good catch and valid point. While it will not change the functionality, it makes the function more correct and clearer.