How to find nodes IDs in communication range of another node? I set communication range of a node to r=100. I wanted to set all those nodes as one hop neighbors which are in its range. How should i do that in omnet++? Any help will be appreciated.
Module positions are set in OMNeT++ via display string tags. You are looking for the first two components of the p tag, which stores modules' positions in a parent module. From these positions, you can derive the modules' distances. For dynamically finding out which modules are in a parent module, refer to the user manual's chapter on exploring the module hierarchy.
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I have a mobility model created by SUMO with area around 2 KM * 2 Km for real map.
I want to compute the results for only part of this model. I read that I can use roiroad or roirect.
Roirect take (x1,y1-x2,y2) as Traci coordination, however, I want to use roiroad to take exactly the cars in specific road.
My question is: if the roiroad function take a string of road name , from where in sumo that I can get this value.
should I construct the map again with Netconvert and using --output-street-names
Edges in SUMO always have an ID. It is stored in the id="..." attribute of the <edge> tag. If you convert a network from some other data format (say, OpenStreetMap) to SUMO's XML representation, you have the option to try and use an ID that closely resembles the road name the edge represents (this is the option you mentioned). The default is to allocate a numeric ID.
Other than by opening the road network XML file in a text editor, you can also find the edge ID by opening the network in the SUMO GUI and right clicking on the edge (or by enabling the rendering of edge IDs in the GUI).
Note that, depending on the application you simulate, you will need to make sure that you have no "gaps" in the Regions Of Interest (ROIs) you specify. When a vehicle is no longer in the ROI its corresponding node is removed from the network simulation. Even if the same vehicle later enters another (or the same) ROI, a brand new node will be created. This is particularly important when specifying edges as ROI (via the roiRoads parameter). Keep in mind that SUMO uses edges not just to represent streets, but also to represent lanes crossing intersections. If you do not specify these internal edges, your ROIs will have small gaps at every intersection.
Note also that up until OMNeT++ 5.0, syntax highlighting of the .ini file in the IDE will (mistakenly) display a string containing a # character as if it were a comment. This is just a problem with the syntax highlighting. The simulation will behave as expected. For example, setting the roiRoads parameter to "-5445204#1 :252726232_7 -5445204#2" in the Veins 4.4 example as follows...
...will result in a Veins simulation where only cars on one of the following three edges are simulated:
on the edge leading to the below intersection; or
on the edge crossing the below intersection; or
on the edge leaving the below intersection.
I am using neo4j-core gem (Neo4j::Node API). It is the only MRI-compatible Ruby binding of neo4j that I could find, and hence is valuable, but its documentation is a crap (it has missing links, lots of typographical errors, and is difficult to comprehend). In the Label and Index Support section of the first link, it says:
Create a node with an [sic] label person and one property
Neo4j::Node.create({name: 'kalle'}, :person)
Add index on a label
person = Label.create(:person)
person.create_index(:name)
drop index
person.drop_index(:name)
(whose second code line I believe is a typographical error of the following)
person = Node4j::Label.create(:person)
What is a label, is it the name of a database table, or is it an attribute peculiar to a node?
If it is the name of a node, I don't under the fact that (according to the API in the second link) the method Neo4j::Node.create and Neo4j::Node#add_label can take multiple arguments for the label. What does it mean to have multiple labels on a node?
Furthermore, If I repeat the create command with the same label argument, it creates a different node object each time. What does it mean to have multiple nodes with the same name? Isn't a label something to identify a node?
What is index? How are labels and indices different?
Labels are a way of grouping nodes. You can give the label to many nodes or just one node. Think of it as a collection of nodes that are grouped together. They allow you to assign indexes and other constraints.
An index allows quick lookup of nodes or edges without having to traverse the entire graph to find them. Think of it as a table of direct pointers to the particular nodes/edges indexed.
As I read what you pasted from the docs (and without, admittedly, knowing the slightest thing about neo4j):
It's a graph database, where every piece of data is a node with a certain amount of properties.
Each node can have a label (or more, presumably?). Think of it as a type -- or perhaps more appropriately, in Ruby parlance, a Module.
It's a database, so nodes can be part of an index for quicker access. So can subsets of nodes, and therefor nodes with a certain label.
Put another way: Think of the label as the table in a DB. Nodes as DB rows, which can belong to one or more labels/tables, or no label/table at all for that matter. And indexes as DB indexes on sets of rows.
I will first provide some background info. This is how my data is stored:
%POM_family{$GAV} = [\%Parents, \%Children]
Before posing my question I will define the above variables the way i use them in my context:
$GAV --> can be considered to be a random node in our dependency tree
%Parents --> a hash which contains the list of nodes that $GAV depends on
%Children--> a hash which contains the list of nodes that depend on our $GAV
My question is the following:
given that we have the parents and children of any chosen node, what algorithm would be appropriate to use in order to analyze from dependency to dependency and find the root $GAV ie the $GAV who has no Parents.
Thanks in advance! :-D
NOTE: if the question is not clear enough, provide some feedback and I will change my question :-)
I am binding a database table data to treeview.
In documntation it is mentioned nodes count property as integer value which is signed 2 byte.
so if the nodes exceeds this range, nodes count is becoming negative.
Is there any workaround for this?
Yes, this is a documented bug. Fortunately, no one ever encounters it in the real world because it's completely nonsensical for a single TreeView control to ever need to display more than 32,767 nodes.
As mentioned in the linked knowledge base article, the best workaround is to maintain less nodes in your TreeView control. Consider splitting the data up between multiple TreeViews, or using a different control that is better suited for such incredibly large quantities of data.
If you absolutely must use a TreeView, Microsoft recommends that you keep the following in mind:
Performance will become extremely slow as you add more and more nodes.
Do not add more than 65535 nodes. (That's the limit imposed by the native control, which uses an unsigned integer to store the node count.)
Use the SendMessage API function to obtain the true node count. Alternately, you can use a module- or public-level variable to keep track of how many nodes are in the TreeView. Each time you add or remove a node, increment or decrement the variable by one. This is necessary if you need to determine the count of nodes because the Count property of the Nodes collection will not return the correct value.
Don't rely on the Index property of a node object. For example, the Index property is 32767 for node 32767 but is -32768 for node 32768.
You can still refer to a node by using its Key or by passing a number to the Nodes collection.
For example:
TreeView1.Nodes(40000) refers to node 40000.
I'm designing a web site navigation hierarchy. It's a tree of nodes. Nodes represent web pages.
Some nodes on the tree are special. I need a name for them.
There are multiple such nodes. Each is the "root" of a sub-tree with pages that have a distinct logo, style sheet, or layout. Think of different departments.
site map with color-coded sub-trees http://img518.imageshack.us/img518/153/subtreesfe1.gif
What should I name this type of node?
How about Root (node with children, but no parent), Node (node with children and parent) and Leaf (node with no children and parent)?
You can then distinguish by name and position within the tree structure (E.g. DepartmentRoot, DepartmentNode, DepartmentLeaf) if need be..
Update Following Comment from OP
Looking at your question, you said that "some" are special, and in your diagram, you have different nodes looking differently at different levels. The nodes may be different in their design, you can build a tree structure many ways. For example, a single abstract class that can have child nodes, if no children, its a leaf, if no parent, its a root but this can change in its lifetime. Or, a fixed class structure in which leafs are a specific class type that cannot have children added to them in any way.
IF your design does not need you to distinguish nodes differently depending on their position (relative to the root) it suggests that you have an abstract class used for them all.
In which case, it raises the question, how is it different?
If it is simply the same as the standard node everywhere else, but with a bit of styling, how about StyledNode? Do you even need it to be seperate (no style == no big deal, it doesn't render).
Since I don't know the mechanics of how the tree is architected, there could possibly be several factors to consider when naming.
The word you are looking for is "Section". It's part of a whole and has the same stuff inside.
So, you have Nodes, which have children and a parent, and you have SectionNodes which are the roots of these special subtrees.
How about PageTemplate to embody the fact that its children have their own layout, CSS etc?
AreaNode
So, it sounds like you are gathering categories. The nodes are the entry points of this categories. How about "TopCategoryNode", "CategoryEntry" then for som,ething that is below them. Or, if you want to divide more, something like "CategoryCSS", "CategoryLayout" etc?
This is kind of generic, but you make clear that there are "categories", and that these do consist of more than one subnode, or subtheme.
Branch ?
Keeps the tree analogy and also hints in this case at departments etc
Thinking about class heirarchies, Root is probably a special case of Branch, which is a special case of Node, special case of Leaf. The Branch/Node distinction is one you get to make for your special situation.