June 2018 - graph-tool - archives.skewed.de

How to control the orientation of the graph topology
by Xun Xiao 26 Feb '22

26 Feb '22

Hi Tiago, sometimes, when delete the graph and create a new one, then plot it, the plotted graph is shown upside down (in terms of the node text). So how could we control the orientation of the graph? Or which parameter we should use to always make node text shown in a correct orientation. Thanks a lot. -- 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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Upside down labels
by charlie 26 Feb '22

26 Feb '22

Hi, I'm suffering from the same issue mentioned in this post: https://git.skewed.de/count0/graph-tool/issues/174 Namely, I'm trying to draw a graph that includes a lot of self-looping edges, and my labels are being printed upside down. If I remove the self-loops the labels are shown the right way up. Is there a fix for it? Thanks, Charlie -- 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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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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assigning vertex properties when adding edges
by m jadidi 04 Mar '20

04 Mar '20

Hi, I was wondering if there is any way to assign vertex properties while adding edges to the graph. for example using "add_edge_list" I can assign edge properties but later I have to iterate through all vertices again to assign their properties. I know this is not a problem when the vertex property is of the type "int" or "float" because then one can use "vprop.a = values", but in case of "string" and "object" this method doesn't work What would be the best/fastest way to handle this situation. I guess it would be very helpful to extend the "add_edge_list" function to accept vertex property in some way. cheers, -- Mohsen

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Nested Block State hierarchy level after mcmc_equilibrate
by ilyco 16 Jan '20

16 Jan '20

I ran mcmc_equilibrate on a nested block state model in a weighted graph. As per instructions, I copied the initially computed state in another object with increased hierarchy depth to 10. However, this fixed the depth to 10. Everything computed afterwards has depth 10 even if is clear that after 3 or 4 levels the nodes converge to one. There are many empty branches and when I try to plot it with empty_branches = False, I get an error stating it is not a tree. RuntimeError: Invalid hierarchical tree: No path from source to target. Did anybody perform any similar analyses? The hierarchy after mcmc_equilibrate: <NestedBlockState object, with base <BlockState object with 24 blocks (24 nonempty), degree-corrected, with 1 edge covariate, for graph <Graph object, undirected, with 230 vertices and 11230 edges, edges filtered by (<PropertyMap object with key type 'Edge' and value type 'bool', for Graph 0x7fc3a89f1210, at 0x7fc3a64911d0>, False), vertices filtered by (<PropertyMap object with key type 'Vertex' and value type 'bool', for Graph 0x7fc3a89f1210, at 0x7fc3a64912d0>, False) at 0x7fc3a89f1210>, at 0x7fc3a6491950>, and 10 levels of sizes [(230, 24), (24, 5), (5, 1), (1, 1), (1, 1), (1, 1), (1, 1), (1, 1), (1, 1), (1, 1)] at 0x7fc3a6491590> -- Sent from: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/

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Problem with add_edge_list(eprop=x)
by JHickey 04 Oct '18

04 Oct '18

I'd like to use the "add_edge_list" function to add edges to my graph, and simultaneously assign a value for an edge property map for each of the added edges. When I try the following example (with no edge property map information) works fine: elist1 = np.array([[0,1], [1, 2]]) #edge list with no value for edge property map data (only the source and target for the edges) g = gt.Graph() my_eprop = g.new_edge_property('bool') g.add_edge_list(elist) But with the following example, I get the error below: elist2 = np.array([[0,1, 1], [1, 2, 0]]) #edge list with edge property map value in 3rd column g = gt.Graph() my_eprop = g.new_edge_property('bool') g.add_edge_list(elist2, eprops=my_eprop) Error: --------------------------------------------------------------------------- ValueError Traceback (most recent call last) <ipython-input-48-6a949ea52c9b> in <module>() ----> 1 g.add_edge_list(elist2, eprops=my_eprop) /usr/lib/python2.7/dist-packages/graph_tool/__init__.pyc in add_edge_list(self, edge_list, hashed, string_vals, eprops) 1969 eprops = () 1970 else: -> 1971 convert = [_converter(x.value_type()) for x in eprops] 1972 eprops = [_prop("e", self, x) for x in eprops] 1973 if not isinstance(edge_list, numpy.ndarray): /usr/lib/python2.7/dist-packages/graph_tool/__init__.pyc in __getitem__(self, k) 534 kt = "Graph" 535 raise ValueError("invalid key '%s' of type '%s', wanted type: %s" --> 536 % (str(k), str(type(k)), kt) ) 537 538 def __setitem__(self, k, v): ValueError: invalid key '0' of type '<type 'int'>', wanted type: Edge --------------------------------------------------------------------------- Please help! -- 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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Using an edge covariate as a hyper parameter for the SBM
by Zahra Sheikhbahaee 20 Jul '18

20 Jul '18

Hi there, I am trying to include the edge weights by taking to account an edge covariate matrix for the nested block model inference. Well, Each time I run the code on my data set I get slightly different results both in terms of number of blocks and the nodes in each block. This is my code: state = minimize_nested_blockmodel_dl(g, state_args=dict(recs=[g.edge_properties["weight"]], rec_types=["discrete-geometric"])) state.draw(edge_color=prop_to_size(g.edge_properties["weight"], power=1, log=True), ecmap=(matplotlib.cm.gist_heat, .6), eorder=g.edge_properties["weight"], edge_pen_width=prop_to_size(g.edge_properties["weight"], 1, 4, power=1, log=True), edge_gradient=[], vertex_text=g.vertex_properties["attribute"], vertex_text_position="centered", vertex_text_rotation=g.vertex_properties['text_rotation'], vertex_font_size=10, vertex_font_family='mono', vertex_anchor=0, output_size=[1024*2,1024*2], output="DiscreteGeometric_%s.pdf"%(eventName)) I appreciate if you explain what your approach would be and how I can run graph-tool using the covariance matrix of edges in order to get statistically reliable results? Is there also any way to get the full posterior of each node belonging to each block? Thanks in advance.

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joblib parallel for with graph-tool filtering?
by Tasos 16 Jul '18

16 Jul '18

With graph-tool and joblib working together, do we need to send graph.copy() in the "Parallel" call like in the code below when using graph vertex filtering with .set_vertex_filter? graph.copy() makes memory usage extreme in large graphs (2M Vs, 4M Es) but in my head ensures any concurrency problems. (or 'graph' without '.copy()' is ok?) What is the best way to run parallel graph searches and filtering (different vertex per thread) with graph-tool and joblib? (or without joblib) ### # defined and filled earlier g_graph = graph_tool.Graph(directed=False) eprop_ang = g_graph.new_edge_property("float") ### from joblib import Parallel, delayed import multiprocessing import os import tempfile import shutil import datetime path2 = tempfile.mkdtemp() out_path2 = os.path.join(path2,'z6path_out2.mmap') out2 = np.memmap(out_path2, dtype=np.float32, shape=(g_graph.num_vertices(),dims), mode='w+') num_cores = 30 num_pre_workers = 60 def runparallel(graph, row, out2): dist, pred = graph_tool.search.dijkstra_search(graph, graph.vertex(row), weight=eprop_ang) ## etc etc ##### v_filter = graph.new_vertex_property('bool',val=False) for v in SOMETHING_LOCAL: v_filter[v] = True graph.set_vertex_filter(v_filter) # do something with the filtered 'graph' (subgraph) # and save output to out2 out4[row] = RESULT ## graph.clear_filters() Parallel(n_jobs=num_cores, pre_dispatch=num_pre_workers, verbose=1)(delayed(runparallel)(g_graph.copy(), r, out2) for r in range(g_graph.num_vertices())) -- Sent from: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/

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Graph database
by Matyas, Csongor 06 Jul '18

06 Jul '18

I know this is a bit off topic, but it might be related to graph-tool also there might be someone here who could help me. I need all the planar graphs that are 4-regular (in the meaning that every vertex has a degree 4) but each graph is allowed to have double edges (not triple or more) also an edge can connect to the same vertex. I couldn't find any database that could give these to me so probably I will have to generate them for myself. Any idea of how could I do this with graph-tool? I know how can I check weather these graphs are planar or not, but the rest seems very complicated. Any help is very much appreciated. Csongor

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Graph thread safety
by mae 02 Jul '18

02 Jul '18

Good morning, I'm considering to use graph-tool as a part of a python web-service providing graph analysis features. Graph-tool performance looks really promising, but I'm not sure if it fits my case. I would like to load graph into the memory and share/read it between multiple threads/processes (to handle many requests in parallel to the same graph). Is Graph thread safe? For me it seems that it's not, but I would like to confirm it. Best Regards, Damian -- Sent from: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/

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