Understanding and Using dot graph

Posted by marsfan on
URL: http://official-rtab-map-forum.206.s1.nabble.com/Understanding-and-Using-dot-graph-tp6492.html

Hello,

I recently found the ability in the database-viewer utility to generate a graphviz .dot file, but I cannot find much documentation on it. If I am correct, this is defining all links found between each image, but that still leaves me with a couple of questions.

1. What is the number on the second line for each node (always 0 or 1 for me)
2. What is the significance of the direction of the arrows? I sometimes have an arrow in each direction, and sometimes only in one direction.
3. Sometimes there is a L, C, Or M next to the arrows? What do these mean?
4. Sometime a number is highlighted, what does this mean?
4. I have tried to use this to identify locations that need to have manual links added, but when I select two images (each at the end of a line), that are visibly next to each other, and click the ADD button in the constraints view, I get the message: "Cannot find a transformation between nodes ### and ###". How can I fix this?