graph-tool July 2014

graph-tool@skewed.de

16 participants
27 discussions

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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Help regarding -enable-openMP
by Shubham Bhushan 11 Nov '15

11 Nov '15

Hi I asked earlier as to how utilize the parallel processing in my code. Now I installed it using the precompiled packages for Ubuntu. does that mean I'll have to reinstall it from source using the openmp option in the configure command? Shubham -- http://about.me/shubham.bhushan

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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.

3 3

Rich-club
by Pablo Fleurquin 30 Jul '14

30 Jul '14

Hi, I'm new with the graph-tool library. I was wondering if there is a function for computing the rich-club coefficient? The coefficient as a function of the vertex degree (slightly different from the assortativity coeficient). To be more specific a function that does the same as this function from networkx: http://networkx.lanl.gov/reference/generated/networkx.algorithms.richclub.r… I think it might be one of these functions: http://graph-tool.skewed.de/static/doc/correlations.html , but I don't know which one specifically. Thank you in advance. Pablo

2 1

Speeding up algorithms with Cython, etc.?
by Gareth Simons 27 Jul '14

27 Jul '14

I have a function that I’m running on subgraphs. It is effectively a bread-first outwards search for all paths from the originating vertex. It assigns probabilities to each of the end-points, which are then used for computing a type of index. In terms of speed, I’ve wondered about three things: 1 - Whether it would be faster to adapt one of the existing graph-tool search algorithms and find a way to assign probabilities from the results… 2 - Whether there are ways to more speedily implement this algorithm through rejigging the algorithm; 3 - And, whether implementing through Cython may provide speedups. Regarding #1, I’ve looked at using the built-in breadth-first search, but I haven’t yet figured out how to use the visitor object to create the list of probabilities. Though will try to take a closer look at this sometime soon. Regarding #3, I’ve looked at a Cython implementation, but it doesn’t appear to provide any significant speedups. I suspect this is because the function uses graph and vertex objects and I’m assuming that Cython doesn’t have the capacity to efficiently implement these. Any pointers would be appreciated. Thanks. Here is the function: (Currently a .pyx file for Cython) from scipy.stats import entropy def nodeOutProb(g, v): # Calculates probabilities of all possible routes from node within cutoff distance visitedNodes = set() claimedEdges = set() branches = {} probabilities = [] # add origin cdef float o = 1.0 branches[v] = o # add starting node with starting probability visitedNodes.add(v) # add starting node to visited set cdef float r, cV, newVal # start iterating through branches...adding and removing as you go while len(branches) > 0: for key, val in branches.items(): newVal = 0.0 newEdges = [] for e in key.all_edges(): if e not in claimedEdges: newVal += 1 claimedEdges.add(e) newEdges.append(e) if newVal == 0: probabilities.append(1/val) else: cV = newVal * val for n in key.all_neighbours(): if n not in visitedNodes: visitedNodes.add(n) branches[n] = cV elif g.edge(key, n) in newEdges: probabilities.append(1/cV) del branches[key] return entropy(probabilities, base=2)

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Speeding up algorithms with Cython, etc.?
by Gareth Simons 27 Jul '14

27 Jul '14

1 0

Compiling graph-tool from source in github
by sabrina 24 Jul '14

24 Jul '14

Hello, I am trying to compile the graph-tool source code I downloaded from github because I need to use the function clustering.motifs with the ordering of motif vertex maps fixed. According to INSTALL one need run ./configure. Since this file is not shipped, I ran " autoreconf -fi" first and I am getting the following error: configure.ac:192: error: possibly undefined macro: AC_PYTHON_DEVEL If this token and others are legitimate, please use m4_pattern_allow. See the Autoconf documentation. Please, how should I proceed? Are there pre-compiled packages (with the ordering of motif vertex maps fixed)? Thank you for any help you can provide. Kind regards, Sabrina. -- 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 July 2014