xt::variance crashes

[TheMrSheldon]

Hello everyone. Thank you very much for your awesome project!

I am currently trying to compute the variance over some tensors but if I supply an axis to calculate the variance for, the program crashes. The following code reproduces this issue:

#include <iostream>

#include <xtensor/xarray.hpp>
#include <xtensor/xio.hpp>
#include <xtensor/xview.hpp>

int main(void) {
    xt::xarray<float> arr = {{1.0f, 2.0f, 3.0f}, {4.0f, 5.0f, 6.0f}, {7.0f, 8.0f, 9.0f}};
    std::cout << xt::variance(arr, {0}) << std::endl;
    // terminate called after throwing an instance of 'std::bad_array_new_length'
    //   what():  std::bad_array_new_length
    std::cout << xt::variance(arr, {1}) << std::endl;
    // terminate called after throwing an instance of 'std::bad_array_new_length'
    //   what():  std::bad_array_new_length
}

Am I missing something?

[spectre-ns]

What compiler are you using? I get the following output when using MSVC 2022 and Intel 2024

{ 6.,  6.,  6.}
{ 0.666667,  0.666667,  0.666667}

[TheMrSheldon]

I am using g++13 within an Ubuntu 24.04 Docker image on an Intel CPU from around 2015 to 2016