Custom VEX functions

I store them here, on Windows:
C:\Users\...\Documents\houdini16.5\vex\include\qq.vfl

I include them in a wrangle like this:
#include "qq.vfl"

Here is the content of the qq.vfl:

void clamp01(float value)
{
    value = clamp(value,0,1);    
}


float falloff_linear(vector sample_pos, from, to) //unclamped
{
    vector u = normalize(to - from);
    vector v = sample_pos - from;

    float eval = dot(u,v) / length(to - from);
    return eval;
}


float falloff_radial(vector sample_pos, center, radius) //unclamped
{
    float max = length(radius - center);
    float eval = length(sample_pos - center) / max;
    return eval;
}


vector farthest_point_position(vector from) //run over detail of input 0
{
    int count = npoints(0);
    float maxdist = 0;
    vector eval;

    for (int pt = 0; pt < count; pt++)
    {
        vector sample_pos = point(0,"P",pt);
        float distance = length(sample_pos - from);
        if (distance > maxdist)    
        {
            maxdist = distance;
            eval = sample_pos;
        }
    }
    return eval;
}


vector farthest_point_distance(vector from) //pointcloud of input 0
{
    int maxpts = npoints(0);
    int handle = pcopen(0, "P", from, radius, maxpts);
    float eval = pcfarthest(handle);
    pcclose(handle);
    return eval;
}


 void bounding_vector (vector direction_from, direction_to, result_from, result_to) //run over detail of input 0
{
    vector u, v, pos, center;
    float distance, mindist, maxdist;
    int count = npoints(0);

    u = normalize(direction_to - direction_from);
    mindist = 1e10;
    maxdist = -1e10;

    for (int pt = 0; pt < count; pt++)
    {    
        pos = point(0,"P",pt);
        v = pos - direction_from;
        distance = dot(u,v);

        maxdist = max(distance, maxdist);
        mindist = min(distance, mindist);
    }

    v = getbbox_center(0) - direction_from;
    center = dot(u,v);

    result_to = (maxdist - center) * u + getbbox_center(0) ;
    result_from = (mindist - center) * u + getbbox_center(0) ;
}


float float_hittest(float try, stored, maxdist) //clamped
{
    float eval, trywide;
    trywide = fit01(try, -maxdist , 1+maxdist);

    if ( maxdist>0 )
    {
        float omin = stored - maxdist;
        float omax = stored + maxdist;
        eval = fit(trywide, omin, omax, 0, 1);
    } else {
        if ( trywide > stored )
        {
            eval = 1;
        } else {
            eval = 0;
        }
    }

    return eval;
}