Skip to main content

How to remap graph properties?


Graph objects support both custom properties, which do not have special meanings, and standard properties, which may be used by some functions.


When importing from formats such as GraphML, we usually get a result with custom properties.


What is the simplest way to remap one property to another, e.g. to remap a custom property to a standard one so it can be used with various functions?




Example: Let's get Zachary's karate club network with edge weights and vertex names from here: http://nexus.igraph.org/api/dataset_info?id=1&format=html


g = Import[

"http://nexus.igraph.org/api/dataset?id=1&format=GraphML", {"ZIP", "karate.GraphML"}]

I can remap "name" to VertexLabels and "weights" to EdgeWeight like this:


sp[prop_][g_] := SetProperty[g, prop]

g2 = g //
sp[EdgeWeight -> (PropertyValue[{g, #}, "weight"] & /@ EdgeList[g])] //
sp[VertexLabels -> (# -> PropertyValue[{g, #}, "name"] & /@ VertexList[g])]

I do find this quite tedious though. I am wondering if there are easier, more streamlined ways to do it.



For example, with igraph this is usually as easy as g.betweeness(weights="weight") (Python) to use the "weight" attribute as edge weights for a betweenness calculation. I know that WeightedAdjacencyMatrix does support such a simple syntax: WeightedAdjacencyMatrix[g, EdgeWeight -> "weight"] uses the "weight" attribute for the matrix. But I don't know if there are simple syntaxes like this in other situations.



Answer



Slightly more cumbersome alternative to your sp (hopefully little less tedious to use):


ClearAll[mapF]
mapF[pr1_ -> pr2_][g_] := SetProperty[g,
pr1 -> Cases[Options@g, Rule[a_, {___, Rule[pr2, v_], ___}] :> Rule[a, v], Infinity]];

mapF[r : (_ -> _) ..][g_] := Fold[mapF[#2][#] &, g, {r}];

g3 = g // mapF[VertexLabels -> "name"]


Mathematica graphics


g4 = g // mapF[VertexLabels -> "name", EdgeWeight -> "weight", VertexSize -> "Faction"]; 

PropertyValue[{g4, #}, VertexLabels] & /@ VertexList[g4]


Mathematica graphics



PropertyValue[g4, EdgeWeight]



{"4", "5", "3", "3", "3", "3", "2", "2", "2", "3", "1", "3", "2", "2", "2", "2", "6", "3", "4", "5", "1", "2", "2", "2", "3", "4", "5", "1", "3", "2", "2", "2", "3", "3", "3", "2", "3", "5", "3", "3", "3", "3", "3", "4", "2", "3", "3", "2", "3", "4", "1", "2", "1", "3", "1", "2", "3", "5", "4", "3", "5", "4", "2", "3", "2", "7", "4", "2", "4", "2", "2", "4", "2", "3", "3", "4", "4", "5"}



Note: the values of weight are strings.


Comments

Popular posts from this blog

plotting - How to draw lines between specified dots on ListPlot?

I would like to create a plot where I have unconnected dots and some connected. So far, I have figured out how to draw the dots. My code is the following: ListPlot[{{1, 1}, {2, 2}, {3, 3}, {4, 4}, {1, 4}, {2, 5}, {3, 6}, {4, 7}, {1, 7}, {2, 8}, {3, 9}, {4, 10}, {1, 10}, {2, 11}, {3, 12}, {4,13}, {2.5, 7}}, Ticks -> {{1, 2, 3, 4}, None}, AxesStyle -> Thin, TicksStyle -> Directive[Black, Bold, 12], Mesh -> Full] I have thought using ListLinePlot command, but I don't know how to specify to the command to draw only selected lines between the dots. Do have any suggestions/hints on how to do that? Thank you. Answer One possibility would be to use Epilog with Line : ListPlot[ {{1, 1}, {2, 2}, {3, 3}, {4, 4}, {1, 4}, {2, 5}, {3, 6}, {4, 7}, {1, 7}, {2, 8}, {3, 9}, {4, 10}, {1, 10}, {2, 11}, {3, 12}, {4, 13}, {2.5, 7}}, Ticks -> {{1, 2, 3, 4}, None}, AxesStyle -> Thin, TicksStyle -> Directive[Black, Bold, 12], Mesh -> Full, Epilog -> { Line[ ...

dynamic - How can I make a clickable ArrayPlot that returns input?

I would like to create a dynamic ArrayPlot so that the rectangles, when clicked, provide the input. Can I use ArrayPlot for this? Or is there something else I should have to use? Answer ArrayPlot is much more than just a simple array like Grid : it represents a ranged 2D dataset, and its visualization can be finetuned by options like DataReversed and DataRange . These features make it quite complicated to reproduce the same layout and order with Grid . Here I offer AnnotatedArrayPlot which comes in handy when your dataset is more than just a flat 2D array. The dynamic interface allows highlighting individual cells and possibly interacting with them. AnnotatedArrayPlot works the same way as ArrayPlot and accepts the same options plus Enabled , HighlightCoordinates , HighlightStyle and HighlightElementFunction . data = {{Missing["HasSomeMoreData"], GrayLevel[ 1], {RGBColor[0, 1, 1], RGBColor[0, 0, 1], GrayLevel[1]}, RGBColor[0, 1, 0]}, {GrayLevel[0], GrayLevel...

list manipulation - Selecting multiple columns from a matrix?

Sample data: data = { {{2013, 1, 1}, 24.13, 167.67, 231.82}, {{2013, 1, 2}, 32.15, 170.92, 225.99}, {{2013, 1, 3}, 35.43, 172.68, 221.67}, {{2013, 1, 4}, 36.73, 173.05, 218.32}, {{2013, 1, 5}, 58.19, 165.96, 197.05}, {{2013, 1, 6}, 69.99, 163.50, 187.52}, {{2013, 1, 7}, 71.37, 154.21, 175.58}, {{2013, 1, 8}, 72.51, 149.66, 163.25}}; I want a DateListPlot with three graphs, so for a matrix formed by columns 1 and 2, one for columns 1 and 3, and 1 for columns 1 and 4. At the moment I'm using this code: data2 = Transpose[{data[[All, 1]], data[[All, 2]]}]; data3 = Transpose[{data[[All, 1]], data[[All, 3]]}]; data4 = Transpose[{data[[All, 1]], data[[All, 4]]}]; DateListPlot[{data2, data3, data4}, Joined -> True, Filling -> {3 -> {1}}] but I have a hunch that this can be done more efficiently. I don't like the Transpose s in particular. Any ideas? edit (for extra credit) What if I need to multiply the second column by 2, which in my solution is simp...