Ask any question about QuantStack projects: xtensor, xeus, voila, Jupyter widgets, mamba
I've also had to argue the case for Jupyter to management so I've kept a list of some references that might be considered more authoritative or tell a story about why it's a useful tool for data science / analytics
it's correctly implemented for
micromamba
we just need to copy the implementation to
mamba
Hello everyone. I am currently trying out xtensor for the first time, and trying to load it as a submodule in CMake. Is that a decent approach to using xtensor on Ubuntu 20.04? I've been getting multiple compilation errors regarding xtl.
/usr/include/xtl/xvariant_impl.hpp:1287:35: error: wrong number of template arguments (1, should be at least 2)
1287 | case B + 29: return MPARK_DISPATCH(B + 29);
| ^~~~~~~~~~~~~~
/usr/include/xtl/xvariant_impl.hpp:1198:16: note: provided for ‘template<bool B, class R, class ... ITs> struct mpark::detail::visitation::base::dispatcher’
1198 | struct dispatcher;
| ^~~~~~~~~~
/usr/include/xtl/xvariant_impl.hpp:1287:35: error: expected ‘;’ before ‘)’ token
1287 | case B + 29: return MPARK_DISPATCH(B + 29);
| ^~~~~~~~~~~~~~
/usr/include/xtl/xvariant_impl.hpp:1287:35: error: expected primary-expression before ‘)’ token
/usr/include/xtl/xvariant_impl.hpp:1288:35: error: wrong number of template arguments (1, should be at least 2)
1288 | case B + 30: return MPARK_DISPATCH(B + 30);
| ^~~~~~~~~~~~~~
/usr/include/xtl/xvariant_impl.hpp:1198:16: note: provided for ‘template<bool B, class R, class ... ITs> struct mpark::detail::visitation::base::dispatcher’
1198 | struct dispatcher;
| ^~~~~~~~~~
/usr/include/xtl/xvariant_impl.hpp:1288:35: error: expected ‘;’ before ‘)’ token
1288 | case B + 30: return MPARK_DISPATCH(B + 30);
Please advice. I'd highly appreciate all comments and suggestions.
Hello, we highly discourage the usage of git submodule, they are conisdered as bad practice regarding management of dependencies. A better approach is to either install the dependencies from sources as explained in the README of the different projects, or use a package manager. We provide packages of the xtensor-stack for mamba, and xtensor has also been packaged for debian. Packages for Ubuntu should be available soon
Hello, is there a minimal cmake example for the section on "Designing language bindings with xtensor" (https://xtensor.readthedocs.io/en/latest/bindings.html) somewhere available? I try to follow the procedure but failing on the last part on exposing the function to Python. Within C++ the generalization is working like charm (at least my tests are running successfully).
3 replies
There isn't such a cmake file unfortunately.
It is very dependent of the language btw, especially for e.g. R and Julia that have weird toolchains on windows.
hey, apologies for the lack of interaction on xtensor-fftw here! gitter isn't really in my system :) I see you were pinging me a few times @JohanMabille @pesterie, best to just hit me up in a github issue (or ask me to come on gitter via github :D chat can be more efficient and i'm always happy to help)
hope you're all doing well! excited to see you're thinking about moving to c++17 btw, that should allow to clean up a lot of code with constexpr if
You could use github code search to find a couple of users: https://github.com/search?q=xtensor.hpp&type=Code
@mircomarahrens you can try https://github.com/DerThorsten/cpp_cookiecutter . this is bit outdated but I personally use it still very often to generate python bindings for c++ projects with a CMake build system + xtensor
Hey folks! I needed some suggestion on a problem that I am facing and was redirected here for asking any questions regarding it. I have been trying to access multiple voila apps through nginx reverse proxy I also have a flask app which I am also using through the same reverse proxy. So, when I am doing so, if i redirected the
location / directly to voila apps while voila app is running locally on my machine, it works. But when I am redirecting it for location /notebook1, I am not able to access the app. I the browser it shows it is loading and kernel is started but gets a 404 in accessing some static files ( ). I am a little new to nginx as well as voila. Any advice or suggestion regarding this would be of great help for me! Here is the nginx.conf file (https://pastebin.com/pHy6pgsU), and here is the voila.json file ( https://pastebin.com/gfx0gE8H), for now have been testing it just for one notebook if it works i will just add for the other two notebooks too with different ports. Here are the error message log I get when I try to open the voila through nginx reverse proxy (https://pastebin.com/C0h7f61S)
Please let me know if any more info is needed.
Hello @ssurbhi560, you might need to set
base_url for Voila (https://github.com/voila-dashboards/voila/blob/b78337b592107fc4824e110d2e311f7a35070f6e/voila/app.py#L152)
in your case you can try
voila ... --base_url=/notebook1/
Hello! Quick question: is there a way to vectorize a C++ function (and expose it in Python as a Numpy ufunc) with arguments of non-POD type (e.g., a custom C++ class exposed in Python)? It doesn’t seem to be supported with pybind11… so I guess it’s not supported either by xtensor-python’s
pyvectorize? I was wondering if there could still be a way around it, e.g., using a lightweight wrapper calling xtensor’s xvectorize?
not 100% sure but you should definitely give it a try
Hello i've been trying the xvega example notebooks (i'm trying to move my visualisations / data analysis from python in jupyter to cpp in jupyter) and find that generating one graph (executing one cell) takes a very long time (~minute) it seems to be around the same on my install and in the binder. Is that expected ? Kinda ruins the "interactive" part so i suppose i must not be using it correctly ?
ICYI Mamba is mentioned as an official install method for Python packages on the AWS SageMaker website. First time I've seen that on such a big website. Kudos to everyone!
I gather there were issues at the start with
track_features or mutex packages but IIUC they've since been solved?
Is
μmamba now a feasible replacement for mamba in a production setting?
...and if not, why not? (maybe the concerns around
μmamba aren't relevant to my particular usage)
I'm wondering if the warnings in the README are still relevant?
It can be used to bootstrap environments but it's currently experimental
Note: it's advised to use micromamba in containers & CI only
