Segmentation fault

[Nightrord]

Running on my network, get following error.

Total vertices : 639 Dimension : 256
Normalizing ...... Done.
Running ANNOY ...... Done.
Running propagation 3/3
Test knn accuracy : 53.93%
Computing similarities ...... Done.
Fitting model Alpha: 0.905441 Progress: 9.456%Segmentation fault

Running it several times, and this is the best result. I don't know what cause the segmentation fault. Could you help me solve this?

Thanks in advance

[qigangliu]

i encounter the same issue, samples 14416, dimensions 369,but when running the example MNIST, it is OK, i guess this problem is caused by the special samples value, but i am not good at debugging c++ code, thanks for any help

[DataWaveAnalytics]

Please, could you post your input data? I can do some debugging of this. BTW you can do debugging using gdb

[mglowacki100]

As far I remember, I have similar issue for MNIST when I've changed n_neihbours from 150 to 10.

[Irene-GM]

I get a similar issue with 46838 samples with 10 dimensions each. These samples are feature vectors normalized between 0 and 1, not similarities. When I run the algorithm with the default parameters, I get a Segmentation Fault:

• In the "Running ANNOY"

• In "Fitting" after 99% (the SegFault is not shown here, sometimes it does not go beyond the ANNOY)

So well, any idea on what could be happening here? I am running this algorithm in a Intel i7 8-core computer with 32gb of RAM, so I guess it is not a matter of lack of computing resources considering the size of my data. Please, could you kindly provide a description of what ANNOY does? Or perhaps to explain a bit more the phases this algorithm goes through? It could be helpful for debugging.

Thanks for your support! :-)

[DataWaveAnalytics]

@Irene-GM try running with GDB to see more details:
gdb --args ./LargeVis -input features.csv ...
Did you check if you have missing values in your data?

Also, have a look to the issue "Potential bug in LargeVis::search_reverse_thread". You should fix the method sample_an_edge as proposed by Sonja and recompile:

long long LargeVis::sample_an_edge(real rand_value1, real rand_value2){ long long k = (long long)(n_edge * rand_value1) - 1; k = max(k, 0); return rand_value2 <= prob[k] ? k : alias[k]; }

[void4]

One reason why this can occur is forgetting to set the -output flag, which makes FOpen fail, which in turn makes fprintf fail