October 2013 - graph-tool - archives.skewed.de

What formula is used for std in vertex_average and edge_average?
by VaSa 16 Jul '20

16 Jul '20

I am curious what is being used to calculate the standard deviation of the average in gt.vertex_average and gt.edge_average >>> t2=gt.Graph() >>> t2.add_vertex(2) >>> t2.add_edge(t2.vertex(0), t2.vertex(1)) >>> gt.vertex_average(t2, "in") (0.5, 0.35355339059327373) Now, shouldn't std be σ(n)=sqrt(((0-0.5)^2+(1-0.5)^2)/2)=0.5 ? also q(n-1)=sqrt((0.5^2+0.5^2)/(2-1))~=0.70710 0.3535 is sqrt(2)/4 which happens to be σ(n-1)/2, so it seems there is some relation to that. A little bigger graph. >>> t3=gt.Graph() >>> t3.add_vertex(5) >>> t3.add_edge(t3.vertex(0), t3.vertex(1)) >>> gt.vertex_average(t3, "in") (0.2, 0.17888543819998318) Now, we should have 0,1,0,0,0 series for vertex incoming degree. So Windows calc gives σ(n)=0.4 and σ(n-1)~=0.44721, so where does 0.1788854 come from ? Reason, I am asking because, I have a large graph, where the average looks quite alright but the std makes no sense, as going by the histogram, degree values are quite a bit more distributed than the std would indicate. -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com… Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.

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graph-tool can't find Graphviz renderer
by Mikhail Spivakov 07 Apr '16

07 Apr '16

Hello! I've got graphviz installed with python and python27 bindings. However, when I do: graph_draw(ug, vprops={"label": ug.vertex_index}, output="two-nodes.pdf", layout="fdp") I get the following error: graph G { graph [outputorder=edgesfirst, mode=major, overlap=true, ratio=fill, size="5.905512,5.905512", start=3019255687130444316]; node [label="\N", shape=circle, width="0.105", height="0.105", style=filled, color="#2e3436", fillcolor="#a40000"]; edge [arrowsize="0.3", color="#2e3436", penwidth="1.0"]; graph [bb="0,0,425,425"]; 0 [label=0, width="0.47", height="0.47", pos="330,101"]; 1 [label=1, width="0.47", height="0.47", pos="93,324"]; 0 -- 1 [pos="318,113 277,152 147,274 106,312"]; } Error: renderer for pdf is unavailable Out[8]: <PropertyMap object with key type 'Vertex' and value type 'vector<double>', for Graph 0x5ff3f90, at 0x6001290> At the same time, if I save the above dot expression as test1.dot and run the following command from the command line: $ dot -Tpng test1.dot -o graph1.png I get a beautiful graph1.png. Graphviz is installed in a non-standard location as I don't have admin rights. However, the graphviz folder is in LD_LIBRARY_PATH and gv.py is in PYTHONPATH. Would very much appreciate your advice on what else graph-tool might need to find the libraries and/or how to test it better. Many thanks, Mikhail

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Segmentation fault using shortest_distance
by Juan Manuel Tirado 20 Mar '16

20 Mar '16

Hi Tiago, I am trying to calculate the shortest distances of a graph after applying a filter. I have a code that looks like this: g=gt.load_graph("myGraph.xml",format="xml") #for later use distances = gt.shortest_distance(g) #extract the components of the graph comp = g.label_components(g) #This splits the graph in several components #I want to calculate the shortest distances #for the component 2 for example filtering = g.new_vertex_property("boolean") for v in g.vertices(): if comp[v]==2: filtering[v]=True else: filtering[v]=False #set the vertex filter g.set_vertex_filter(filtering) distances_comp=gt.shortest_distance(g) The last line of code rises a segmentation fault. I have plotted the graph with the filtered graph and its correct, also I can calculate the local_clustering_coefficient without problems. Am I doing something wrong? Is there any other way to filter the graph and calculate the shortest distances? Is this a bug? Thanks so much, Juan

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graph-tool graphml and networkx
by tcb 17 Aug '15

17 Aug '15

Hi, I am trying to read the graphml output of graph-tool's graphml using networkx. https://github.com/networkx/networkx/issues/843 Unfortunately this does not work with any of the vector_* type property maps which graph-tool uses. Have you encountered this issue before? It seems the right thing to do might be to extend your graphml to hold the vector_* attributes as detailed: http://graphml.graphdrawing.org/primer/graphml-primer.html#EXT Is there some reason why it was done the way it is? How do you manage read/writing graphml data to other tools? In the meantime, it might be possible to hack some read support for graph-tool's xml into networkx. To this end, could you please advise how to parse the 'key1' data (should be two floats) <node id="n1"> <data key="key0">6</data> <data key="key1">0x1.5c71d0cb8d943p+3, 0x1.70db7f4083655p+3</data> </node> thanks - -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com… Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.

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Undefined symbol drawing function
by sasho.j.markov 20 Apr '15

20 Apr '15

Hi New to the graph-tool. Build it from src on Fedora 16 (64) . Built with cairomm enabled . Try to run as per the quick start , however when executing graph_draw(g, vertex_text=g.vertex_index, vertex_font_size=18, ... output_size=(200, 200), output="two-nodes.pdf") i get undefined symbol _ZN5Cairo7ContextC1EP6_cairob However the symbol above is defined in : libcairomm-1.0.so see below nm command results nm /usr/local/lib/libcairomm-1.0.so | grep -i _ZN5Cairo7ContextC1EP6_cairob 0000000000014b90 T _ZN5Cairo7ContextC1EP6_cairob Interestingly the library libgraph_tool_draw.so has indeed have the undefined symbol U _ZN5Cairo7ContextC1EP6_cairob but does not depend on the cairomm libarary - see the ldd output . unless the library is dynamically load i do not understand why Any advise appreciated- regards Sasho ldd /usr/local/lib/python2.7/site-packages/graph_tool/draw/libgraph_tool_draw.so linux-vdso.so.1 => (0x00007fffc46da000) libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f99fd6cd000) libpython2.7.so.1.0 => /usr/lib64/libpython2.7.so.1.0 (0x00007f99fd30e000) libboost_iostreams.so.1.49.0 => /usr/local/lib/libboost_iostreams.so.1.49.0 (0x00007f99fd0f6000) libboost_python.so.1.49.0 => /usr/local/lib/libboost_python.so.1.49.0 (0x00007f99fceaa000) libboost_regex.so.1.49.0 => /usr/local/lib/libboost_regex.so.1.49.0 (0x00007f99fcbc8000) libCGAL.so.9 => /usr/local/lib/libCGAL.so.9 (0x00007f99fc9a5000) libexpat.so.0 => /usr/local/lib/libexpat.so.0 (0x00007f99fc77c000) libbz2.so.1 => /lib64/libbz2.so.1 (0x00007f99fc54d000) libm.so.6 => /lib64/libm.so.6 (0x00007f99fc2c9000) libc.so.6 => /lib64/libc.so.6 (0x00007f99fbf11000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f99fbcfb000) /lib64/ld-linux-x86-64.so.2 (0x00000030cea00000) libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f99fbadf000) libdl.so.2 => /lib64/libdl.so.2 (0x00007f99fb8db000) libutil.so.1 => /lib64/libutil.so.1 (0x00007f99fb6d7000) libz.so.1 => /lib64/libz.so.1 (0x00007f99fb4c0000) librt.so.1 => /lib64/librt.so.1 (0x00007f99fb2b8000) libgmpxx.so.4 => /usr/lib64/libgmpxx.so.4 (0x00007f99fb0b3000) libboost_thread.so.1.49.0 => /usr/local/lib/libboost_thread.so.1.49.0 (0x00007f99fae98000) libgmp.so.3 => /usr/lib64/libgmp.so.3 (0x00007f99fac41000) -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com… Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.

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Problem importing on Mac OS X 10.8, installed using MacPorts
by Uldis Bojars 07 Mar '14

07 Mar '14

Hi, When trying to import graph-tool the following error message is returned: >>> from graph_tool.all import * Fatal Python error: PyThreadState_Get: no current thread Could you help me solve this problem? graph-tool version py-graph-tool-2.2.18 was successfully installed using MacPorts but it fails during importing. Thanks, Uldis

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Parallel Processing
by Derek Ditch 21 Nov '13

21 Nov '13

I want to use graph-tool using the multiprocessing library in Python 2.6. I keep running into issues though with trying to share a full graph object. I can store the graph in a multiprocessing.Namespace, but it doesn't keep the dicts of properties. Example: def initNS( ns ): _g = Graph( directed = False) ns.graph = _g ns.edge_properties = { 'genres': _g.new_edge_property("vector<string>"), 'movieid': _g.new_edge_property("int"), } ns.vertex_properties = { 'personid': _g.new_vertex_property("int32_t") } """ Build property maps for edges and vertices to hold our data The graph vertices represent actors whereas movies represent edges """ # Edges _g.edge_properties["genres"] = ns.edge_properties['genres'] _g.edge_properties["movieid"] = ns.edge_properties['movieid'] # Vertices _g.vertex_properties["personid"] = ns.vertex_properties['personid'] ns.graph = _g ########## This initializes 'ns', which is a multiprocessing.Namespace. The problem is that for example, ns.edge_properties[ * ] tells me that the type isn't pickle-able. I tried to just skip that and use the _g.edge_properties to access it, but those dicts aren't carried over to the different process in the pool. Presumably b/c they aren't pickle-able. Any thoughts about how to fix this? (For those interested, I'm attempting to use the IMDbPy library to do some graph analysis on the relationships among actors and movies. Each process has it's own db connection and trying to populate the graph with actor and movie information in parallel since it's a pretty large and dense graph. Somewhere in the neighborhood of 250,000+ vertices for just a depth of three relationships) Thanks, -- Derek

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Katz centrality calculation
by xenil 08 Nov '13

08 Nov '13

Hi, I'm testing the Katz centrality function in order to use in a project. In order to calculate the Katz centrality and following the graph_tool documentation I supposed that you use: (I - \alpha A) x = \beta x = \beta / (I - \alpha A) = (I + \alpha A + \alpha^2 A^2 + ... ) \beta where I is the identity matrix and there was appllied the geometric series expansion. My first test was to take a simple circular directed graph with 4 nodes. I used the attached test program with the attached graph file. The adjacency matrix for this graph, A, is: 0 0 0 1 1 0 0 0 0 1 0 0 0 0 1 0 I used distinct values of the max_iter parameter and I set \alpha=1. I use 4 unitary vectors as beta parameter in order to obtain the contents of the calculation matrix (I + \alpha A + \alpha^2 A^2 + ... ), I'll call the F matrix. The test results are for \alpha=1: a) max_iter=1, F matrix is: 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 expected matrix, F = I b) max_iter=2, F matrix is: 0.7 0.0 0.5 0.5 0.5 0.7 0.0 0.5 0.5 0.5 0.7 0.0 0.0 0.5 0.5 0.7 when the expected matrix, F = I + A, is: 1 0 0 1 1 1 0 0 0 1 1 0 0 0 1 1 c) max_iter=3, F matrix is: 0.7 0.0 0.5 0.5 0.5 0.7 0.0 0.5 0.5 0.5 0.7 0.0 0.0 0.5 0.5 0.7 the same as for case max_iter=2 when the expected matrix, F = I + A + A^2, is: 1 0 1 1 1 1 0 1 1 1 1 0 0 1 1 1 d) max_iter=4, F matrix is: 0.52 0.30 0.63 0.48 0.48 0.52 0.30 0.63 0.63 0.48 0.52 0.30 0.30 0.63 0.48 0.52 when the expected matrix, F = I + A + A^2 + A^3, is: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 The first finding was that a normalization is done during the intermediate steps of the calculation because the diagonal elements are changing of value. I look at the graph_katz.hh file and i havesome questions: a) Line 72: c_temp[v] += alpha * get(w, *e) * c[s]; when w is not specified, What w value is used? The normalized adjacency matrix value? b) Line 87: c_temp[v] /= norm; after the swap of the line 90. Could be this the intermediate step nomralization? Is this correct? Thanks in advance, David. katz.py <http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com…> test4.xml <http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com…> -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com… Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.

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Re: [graph-tool] Rendering text labels over vertices
by Giovanni Luca Ciampaglia 30 Oct '13

30 Oct '13

Hi Tiago, Yes I thought about vorder but I have too many vertices. I got away with selecting a layout with few overlaps and then fixing by hand the generated PDF with inkscape. Worked great! I have opened a new ticket (#147). Thanks! Giovanni On 10/29/2013 08:00 AM, graph-tool-request(a)skewed.de wrote: > Hi Giovanni, > > On 10/28/2013 12:56 AM, Giovanni Luca Ciampaglia wrote: > > I am plotting text labels next to vertices but some vertices cover the > > text of other vertices. Is there a way to ensure that the text is > > displayed on the foreground? I am using graph_draw. > > The texts are currently drawn together with the vertices. You can avoid > obscuring text to some extent by specifying the vertex order via the > "vorder" parameter. > > An option to force the drawing of texts above all vertices would be a > nice improvement. If you want, you can open a bug report for this, and > I'll around to it when I find some time. > > Cheers, > Tiagon > > -- > Tiago de Paula Peixoto <tiago(a)skewed.de> -- Giovanni Luca Ciampaglia Postdoctoral fellow Center for Complex Networks and Systems Research Indiana University ✎ 910 E 10th St ∙ Bloomington ∙ IN 47408 ☞ http://cnets.indiana.edu/ ✉ gciampag(a)indiana.edu

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Rendering text labels over vertices
by Giovanni Luca Ciampaglia 28 Oct '13

28 Oct '13

I am plotting text labels next to vertices but some vertices cover the text of other vertices. Is there a way to ensure that the text is displayed on the foreground? I am using graph_draw. Cheers, -- Giovanni Luca Ciampaglia Postdoctoral fellow Center for Complex Networks and Systems Research Indiana University ✎ 910 E 10th St ∙ Bloomington ∙ IN 47408 ☞ http://cnets.indiana.edu/ ✉ gciampag(a)indiana.edu

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