1 function d3_uninterpolateNumber(a, b) {

     2   b = b - (a = +a) ? 1 / (b - a) : 0;

     3   return function(x) { return (x - a) * b; };

     4 }

     5 

     6 function d3_uninterpolateClamp(a, b) {

     7   b = b - (a = +a) ? 1 / (b - a) : 0;

     8   return function(x) { return Math.max(0, Math.min(1, (x - a) * b)); };

     9 }