Residua Distribution of signs

residualSignDistribution.js

// One way to measure goodness of fit is to
// assess the even distribution of values arround 
// the regression line. This is a non-parameric
// approach that is not sensitive to the magitude
// of the noise, only to its structure

RSD={
  res2sign:function(r){ // counts same-sideness of residuals in array r
    var rs = 0
    for(var i=1;i<r.length;i++){rs+=((r[i]*r[i-1])>0)}
    return rs
  }
  
}