Figure full refreshes on changing anything?

[contagon]

I'm currently trying to live plot an algorithm I'm developing, however, when updating the axis, the plot does a quick flash. This makes things unusable when updating too frequently. It also doesn't appear to matter what I'm changing - something as small as line thickness also seems to cause this.

int main() {
    using namespace matplot;
    int n = 10000;
    std::vector<double> x = linspace(0, 2 * pi, n);
    std::vector<double> y = transform(x, [](auto x) { return sin(x); });

    auto f = figure(false);
    auto ax = gca();
    auto p = ax->plot(x,y);
    f->draw();

    for(int i=10;i<n;i++){
        p->color("red").line_width(2);
        sleep(.1);
    }
    
    return 0;
}

Is there something I'm doing incorrectly here? Is this just a general limitation of matplotplusplus? I've tried a similar experiment using gnuplot directly, and I don't seem to get any of the refreshes.

Thanks! And thanks for all your work on this, I believe it's going to be my go-to plotting tool for C++.

[alandefreitas]

You're not doing anything incorrectly. It's a limitation with the backend, which is based on process pipes. You might try using another gnuplot terminal, but updating plots very frequently is unlikely to work without these flashes because the pipe is redrawing the whole figure. We're working on another backend but this is going to take a while.

[Haron123]

Is there already a way to live plot without the full figure refreshing currently ?

[alandefreitas]

Not really. Not a lot of work going into this library lately.