javascript - How to round smoothly percentage in JS -

i have object containing decimals values : evo, meteo , usage try display values 3 conditions :

• values can positive , negative
• values must displayed percentage without decimals
• (a) must true

(a): math.round(meteo*100)+math.round(usage*100) = math.round(evo*100)

for example, if apply these values

{evo: 0.1466, meteo: 0.1231, usage: 0.0235} 

we unvalid percentages :

evo: 15% meteo: 12% usage: 2% 

because values rounded, (a) isn't verified. working on getsmooth function adjust rounded values equation (a) verified.

var smooth = getsmooth(math.round(evo*100), math.round(meteo*100), math.round(usage*100);  function getsmooth(evo, meteo, usage){     // case need incremente     if( math.abs(evo) > math.abs(meteo) + math.abs(usage) ){         // case need incremente usage         if( math.abs(meteo) > math.abs(usage) ){             (usage > 0) ? usage++ : usage--;         }         // case need incremente meteo         else{             (meteo > 0) ? meteo++ : meteo--;         }     }     // case need decremente     else{         // case need decremente usage         if( math.abs(meteo) > math.abs(usage) ){             (usage > 0) ? usage-- : usage++;         }         // case need decremente meteo         else{             (meteo > 0) ? meteo-- : meteo++;         }     }      return {         evo: evo,         meteo: meteo,         usage: usage     }; } 

my function isn't workind well, , handle +1 incrementation/decrementation. pretty sure doing hard way.

is there easier way achieve task ?

try this:

function getsmooth(meteo, usage) {     meteo = math.round(meteo*100);     usage = math.round(usage*100);     return {         evo: (meteo + usage) / 100,         meteo: meteo / 100,         usage: usage / 100     }; } 

to test errors in calculations in evo separate visualisation logic:

var evo, meteo, usage; // ... // error handling var eps = 1e-4; // float precision epsilon if(math.abs(evo - (meteo + usage)) > eps) {      // there's error in evo... } // processing var smooth = getsmooth(meteo, usage); // continue smooth...