當使用itorch時無法加載Lib graphviz

Question

我正在學習火炬，並遵循火炬團隊提供的教程。當我打的「NNGraph教程」作爲提供以下線等......意想不到的事情發生：

-- it is common style to mark inputs with identity nodes for clarity. 
input = nn.Identity()() 

-- each hidden layer is achieved by connecting the previous one 
-- here we define a single hidden layer network 
h1 = nn.Tanh()(nn.Linear(20, 10)(input)) 
output = nn.Linear(10, 1)(h1) 
mlp = nn.gModule({input}, {output}) 

x = torch.rand(20) 
dx = torch.rand(1) 
mlp:updateOutput(x) 
mlp:updateGradInput(x, dx) 
mlp:accGradParameters(x, dx) 

-- draw graph (the forward graph, '.fg') 
-- this will produce an SVG in the runtime directory 
graph.dot(mlp.fg, 'MLP', 'MLP') 
itorch.image('MLP.svg') 

錯誤信息：

...s/noahcao/torch/install/share/lua/5.2/graph/graphviz.lua:157: graphviz library could not be loaded. 
stack traceback: 
/Users/noahcao/torch/install/share/lua/5.2/itorch/main.lua:167: in function </Users/noahcao/torch/install/share/lua/5.2/itorch/main.lua:160> 
[C]: in function 'error' 
...s/noahcao/torch/install/share/lua/5.2/graph/graphviz.lua:157: in function 'graphvizFile' 
...s/noahcao/torch/install/share/lua/5.2/graph/graphviz.lua:197: in function 'dot' 
[string "-- it is common style to mark inputs with ide..."]:18: in main chunk 
[C]: in function 'xpcall' 
/Users/noahcao/torch/install/share/lua/5.2/itorch/main.lua:210: in function </Users/noahcao/torch/install/share/lua/5.2/itorch/main.lua:174> 
(...tail calls...) 
/Users/noahcao/torch/install/share/lua/5.2/lzmq/poller.lua:75: in function 'poll' 
...s/noahcao/torch/install/share/lua/5.2/lzmq/impl/loop.lua:307: in function 'poll' 
...s/noahcao/torch/install/share/lua/5.2/lzmq/impl/loop.lua:325: in function 'sleep_ex' 
...s/noahcao/torch/install/share/lua/5.2/lzmq/impl/loop.lua:370: in function 'start' 
/Users/noahcao/torch/install/share/lua/5.2/itorch/main.lua:389: in main chunk 
[C]: in function 'require' 
(command line):1: in main chunk 
[C]: in ? 

但我查了graphviz.lua文件，這似乎是確定。我無法理解這些信息想告訴我什麼。

Answer 1

我也遇到了同樣的問題。這解決了我的問題：

# Mac users 
brew install graphviz 

# Debian/Ubuntu users 
sudo apt-get install graphviz -y 

希望這可能有助於某人。

請檢查這個​​爲火炬的圖包。