Function PlotHistogram

src-core/imgui/implot/implot_items.cpp:2505–2581

template <typename T>
double PlotHistogram(const char* label_id, const T* values, int count, int bins, double bar_scale, ImPlotRange range, ImPlotHistogramFlags flags) {

    const bool cumulative = ImHasFlag(flags, ImPlotHistogramFlags_Cumulative);
    const bool density    = ImHasFlag(flags, ImPlotHistogramFlags_Density);
    const bool outliers   = !ImHasFlag(flags, ImPlotHistogramFlags_NoOutliers);

    if (count <= 0 || bins == 0)
        return 0;

    if (range.Min == 0 && range.Max == 0) {
        T Min, Max;
        ImMinMaxArray(values, count, &Min, &Max);
        range.Min = (double)Min;
        range.Max = (double)Max;
    }

    double width;
    if (bins < 0)
        CalculateBins(values, count, bins, range, bins, width);
    else
        width = range.Size() / bins;

    ImPlotContext& gp = *GImPlot;
    ImVector<double>& bin_centers = gp.TempDouble1;
    ImVector<double>& bin_counts  = gp.TempDouble2;
    bin_centers.resize(bins);
    bin_counts.resize(bins);
    int below = 0;

    for (int b = 0; b < bins; ++b) {
        bin_centers[b] = range.Min + b * width + width * 0.5;
        bin_counts[b] = 0;
    }
    int counted = 0;
    double max_count = 0;
    for (int i = 0; i < count; ++i) {
        double val = (double)values[i];
        if (range.Contains(val)) {
            const int b = ImClamp((int)((val - range.Min) / width), 0, bins - 1);
            bin_counts[b] += 1.0;
            if (bin_counts[b] > max_count)
                max_count = bin_counts[b];
            counted++;
        }
        else if (val < range.Min) {
            below++;
        }
    }
    if (cumulative && density) {
        if (outliers)
            bin_counts[0] += below;
        for (int b = 1; b < bins; ++b)
            bin_counts[b] += bin_counts[b-1];
        double scale = 1.0 / (outliers ? count : counted);
        for (int b = 0; b < bins; ++b)
            bin_counts[b] *= scale;
        max_count = bin_counts[bins-1];
    }