X-Git-Url: https://www.fleuret.org/cgi-bin/gitweb/gitweb.cgi?p=dagnn.git;a=blobdiff_plain;f=README.md;h=fa77a7e785ccdb23880cacdea55e5d609f294399;hp=91c7684fbb5628bd8af89a4e5086fd31a2bef601;hb=HEAD;hpb=97142a40458218b9674a2fc9fc8876f2b38531f5 diff --git a/README.md b/README.md index 91c7684..fa77a7e 100644 --- a/README.md +++ b/README.md @@ -1,11 +1,14 @@ +# Introduction # -This package implements a new module nn.DAG which inherits from nn.Container and allows to combine modules in an arbitrary graph without cycle. +This package implements a new module nn.DAG for the [torch framework](https://torch.ch), +which inherits from [nn.Container](https://github.com/torch/nn/blob/master/Container.lua) and allows to combine modules in an +arbitrary [Directed Acyclic Graph (DAG).](https://en.wikipedia.org/wiki/Directed_acyclic_graph) -#Example# +## Example ## A typical use would be: -```Lua +```lua model = nn.DAG() a = nn.Linear(100, 10) @@ -14,11 +17,11 @@ c = nn.Linear(10, 15) d = nn.CMulTable() e = nn.Linear(15, 15) -model:addEdge(a, b) -model:addEdge(b, nn.Linear(10, 15), nn.ReLU(), d) -model:addEdge(b, c) -model:addEdge(c, d) -model:addEdge(c, nn.Mul(-1), e) +model:connect(a, b) +model:connect(b, nn.Linear(10, 15), nn.ReLU(), d) +model:connect(b, c) +model:connect(c, d) +model:connect(c, nn.Mul(-1), e) model:setInput(a) model:setOutput({ d, e }) @@ -40,14 +43,79 @@ which would encode the following graph and run a forward pass with a random batch of 30 samples. -Note that DAG:addEdge allows to add a bunch of edges at once. This is particularly useful to add anonymous modules which have a single predecessor and successor. +Note that DAG:connect allows to add a bunch of edges at once. This is +particularly useful to add anonymous modules which have a single +predecessor and successor. -#Input and output# +# Usage # -If a node has a single successor, its output is sent unchanged as input to that successor. If it has multiple successors, the outputs are collected into a table, and the table is used as input to the successor node. The indexes of the outputs in that table reflects the order in which they appear in the addEdge commands. +## Input and output ## -The expected input (respectively the produced output) is a nested table of inputs reflecting the structure of the nested table of modules provided to DAG:setInput (respectively DAG:setOutput) +The DAG can deal with modules which take as input and produce as +output tensors and nested tables of tensors. -So for instance, in the example above, the model expects a tensor as input, since it is the input to the module a, and its output will is a table composed of two tensors, corresponding to the outputs of d and e respectively. +If a node has a single predecessor, the output of the latter is taken +as-is as the input to the former. If it has multiple predecessors, all +the outputs are collected into a table, and the table is used as +input. The indexes of the outputs in that table reflect the +chronological order in which the edges where created in the +DAG:connect() commands. -*Francois Fleuret, Jan 12th, 2017* +The input to the DAG (respectively the produced output) is a nested +table of inputs reflecting the structure of the nested table of +modules given as argument to DAG:setInput (respectively DAG:setOutput) + +So for instance, in the example above, the model expects a tensor as +input, since it is the input to the module a, and its output is a +table composed of two tensors, corresponding to the outputs of d and e +respectively. + +## Functions ## + +### nn.DAG() ### + +Create a new empty DAG, which inherits from nn.Container. + +### nn.DAG:connect(module1, module2 [, module3, [...]]) ### + +Add new nodes corresponding to the modules passed as arguments if they +have not been already added in a previous call. Add edges between +every two nodes associated to two successive modules in the +arguments. + +Calling this function with n > 2 arguments is strictly equivalent to +calling it n-1 times on the pairs of successive arguments. + +Accepting more than two arguments allows in particular to add +anonymous modules, which are not associated to variables. In principle +the only ones that have to be non-anonymous are those that have more +than one successor/predecessor and/or are inputs/outputs. + +### nn.DAG:setInput(i) ### + +Define the content and structure of the input. The argument should be +either a module, or a (nested) table of modules. The input to the DAG +should be a (nested) table of inputs, with the corresponding +structure. + +### nn.DAG:setOutput(o) ### + +Similar to DAG:setInput(). + +### nn.DAG:print() ### + +Print the list of nodes. + +### nn.DAG:saveDot(filename) ### + +Save a dot file to be used by the Graphviz set of tools for graph +visualization. This dot file can than be used for instance to produce +a pdf file such as [this one](https://fleuret.org/git-extract/dagnn/graph.pdf) with + +``` +dot graph.dot -T pdf -o graph.pdf +``` + +### nn.DAG:setLabel(module, name) ### + +Add a label to the given module, that will be used for DAG:print() and DAG:saveDot()