使用DiagrammeR进行路径图（SEM）

Question

我正在测试新的DiagrammeR包的功能，以便可视化结构方程模型。

我的目标是，获得这样的情节：

也许我需要找到一个关于如何指定边和节点方向的资源，因为 - DiagrammeR - 我现在只能做这样的情节：

devtools::install_github('rich-iannone/DiagrammeR')
library('DiagrammeR')

#----------

test<-grViz("     
digraph CFA{

# latent variables
node [shape=circle]
latent_a [group='a']; 
latent_b [group='b'];

#regressions
latent_a -> latent_b [label='0.279'];

#measurement model for latent a
subgraph A{
node [shape=box]
ind_1; 
ind_2; 
ind_3; 
latent_a -> ind_1 [label='0.636'];
latent_a -> ind_2 [label='0.825'];
latent_a -> ind_3 [label='0.829'];
}

#measurement model for latent b
subgraph B{
node [shape=box]
ind_4 ; 
ind_5 ;
latent_b -> ind_4 [label='1.027'];
latent_b -> ind_5 [label='0.626'];
}

#residuals
node [shape=circle]
e1 ; 
e4 ;
e5 ;
e6 ;
e1 -> ind_1;
e4 -> ind_4;
e5 -> ind_5;
e6 -> latent_b;

#residual covariances
ind_1 -> ind_2 [dir=both];
}      
")
test

我会感谢任何提示。

PS：也许我的DiagrammeR - 代码看起来很有趣。我试着以相同的方式编写它，在lavaan中指定了一个模型。也许将来有一种方法可以在两种包之间进行转换。我想，这可能是可能的。

Answer 1

我提出了一些有点手动的东西，但我确信通过制作适当的R函数可以生成DOT代码。这是手动解决方案：

devtools::install_github("rich-iannone/DiagrammeR")
library(DiagrammeR)

grViz("
digraph SEM {

graph [layout = neato,
       overlap = true,
       outputorder = edgesfirst]

node [shape = rectangle]

a [pos = '-4,1!', label = 'e1', shape = circle]
b [pos = '-3,1!', label = 'ind_1']
c [pos = '-3,0!', label = 'ind_2']
d [pos = '-3,-1!', label = 'ind_3']
e [pos = '-1,0!', label = 'latent a', shape = ellipse]
f [pos = '1,0!', label = 'latent b', shape = ellipse]
g [pos = '1,1!', label = 'e6', shape = circle]
h [pos = '3,1!', label = 'ind_4']
i [pos = '3,-1!', label = 'ind_5']
j [pos = '4,1!', label = 'e4', shape = circle]
k [pos = '4,-1!', label = 'e5', shape = circle]

a->b
e->b [label = '0.6']
e->c [label = '0.6']
e->d [label = '0.6']

e->f [label = '0.321', headport = 'w']
g->f [tailport = 's', headport = 'n']

d->c [dir = both]

f->h [label = '0.6', tailport = 'ne', headport = 'w']
f->i [label = '0.6']

j->h
k->i

}
")