Graphviz 繪製 HMM、CRF、SLDS－Banco Blog

Graphviz (Graph Visualization Software) 是 AT&T 用來自動產生圖形的程式，它包含數個執行檔，其中較常用的為 dot 這支程式，dot 可以處理有向圖 (Directed Graph)跟無向圖 (Undirected Graph)。Graphviz 有趣的地方在於整個圖形的排版是由程式自動決定的，只要輸入符合語法的程式碼，經過 dot 處理後即能產生對應的圖檔。以下是今天試用的幾個結果以及其程式碼。

程式碼用一般文書編輯器處理完後，存成 abc.dot 檔，然後輸入下列指令讓它產生 PNG 格式的圖檔。

> dot -Tpng -o abc.png abc.dot

或是在 vi (vim) 的命令列模式輸入

:! dot -Tpng -o abc.png abc.dot

HMM

digraph HMM{
node [fixedsize=true, width=0.6];
"s(t-1)" [shape=rect];
"s(t)" [shape=rect];
"s(t+1)" [shape=rect];

"v(t-1)" [shape=circle, style=filled, fillcolor=grey];
"v(t)" [shape=circle, style=filled, fillcolor=grey];
"v(t+1)" [shape=circle, style=filled, fillcolor=grey];

"s(t-1)" -> "s(t)" -> "s(t+1)";

"s(t-1)" -> "v(t-1)";
"s(t)"->"v(t)";
"s(t+1)"->"v(t+1)";

{ rank=same; "s(t-1)" "s(t)" "s(t+1)" }
{ rank=same; "v(t-1)" "v(t)" "v(t+1)" }
}

CRF

graph CRF{
node [fixedsize=true, width=0.6];
"s(t-1)" [shape=rect];
"s(t)" [shape=rect];
"s(t+1)" [shape=rect];

"v(t-1)" [shape=circle, style=filled, fillcolor=grey];
"v(t)" [shape=circle, style=filled, fillcolor=grey];
"v(t+1)" [shape=circle, style=filled, fillcolor=grey];

"s(t-1)"--"s(t)"--"s(t+1)";

"s(t-1)" -- "v(t-1)";
"s(t)"--"v(t)";
"s(t+1)"--"v(t+1)";

{ rank=same; "s(t-1)" "s(t)" "s(t+1)" }
{ rank=same; "v(t-1)" "v(t)" "v(t+1)" }
}

SLDS

digraph ALDS{
node [fixedsize=true, width=0.6];
"s(t-1)" [shape=rect];
"s(t)" [shape=rect];
"s(t+1)" [shape=rect];

"h(t-1)" [shape=circle];
"h(t)" [shape=circle];
"h(t+1)" [shape=circle];

"v(t-1)" [shape=circle, style=filled, fillcolor=grey];
"v(t)" [shape=circle, style=filled, fillcolor=grey];
"v(t+1)" [shape=circle, style=filled, fillcolor=grey];

"s(t-1)" -> "s(t)" -> "s(t+1)";
"h(t-1)" -> "h(t)" -> "h(t+1)";

"s(t-1)" -> "h(t-1)" -> "v(t-1)";
"s(t)"-> "h(t)" -> "v(t)";
"s(t+1)"-> "h(t+1)" -> "v(t+1)";

{ rank=same; "s(t-1)" "s(t)" "s(t+1)" }
{ rank=same; "v(t-1)" "v(t)" "v(t+1)" }
{ rank=same; "h(t-1)" "h(t)" "h(t+1)" }
}