Potential issue with small numbers in loglog plot

[williamdwarke]

Hi all, I'm posting this in Discussions as opposed to Issues because I'm not actually sure if I'm doing something wrong. I'm trying to plot a line of slope 2 in log-log space, with x-values ranging from 1e-8 to 1e0. However, the matplot loglog plotter seems to be throwing out quite a few of the points, namely, those with y-values less than 1e-10. (For reference, the first 100 or so y-values range between 1e-16 and 1e-10). I'd really appreciate it if somebody could take a look and let me know if I've done something wrong, or if I should submit this as a bug report. I've included a minimal working version of my code, as well as the plot it produces. Thank you!

#include <iostream>
#include <matplot/matplot.h>

int main(int argc, char **argv) {
    // Number of data points
    int N = 1000;

    // Generate N logspaced X values between 10^-8 and 10^0
    double start = -8;
    double end = 0;
    std::vector<double> t = matplot::logspace(start, end, N);

    // Y values (slope 2 in log space)
    std::vector<double> log_slope_2(N);

    // Compute log slope 2 line
    for (int i = 0; i < N; i++) {
        log_slope_2[i] = std::pow(10, 2*log10(t[i]));
    }
    
    // Uncomment to print points to command line
    // for (int i = 0; i < N; i++) {
    //     std::cout << "(" << t[i] << ", " << log_slope_2[i] << "), ";
    // }
    // std::cout << std::endl;

    auto plt = matplot::loglog(t, log_slope_2);
    plt->line_width(2);
    
    matplot::show();
    return 0;
}