JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://canvasjs.com/assets/script/canvasjs.min.js"></script>

<title>HTML5, CSS3 and JavaScript demo</title>


  <script src="http://canvasjs.com/assets/script/canvasjs.min.js"></script>
  	<div id="section">
      <h1>Sustav prvog reda</h1> 
   <br />Unesite parametre sustava:
   <br />Vremenska konstanta T: <input type="text" id="vremKonst" /> Stupanj prigušenja(Zeta) Z: <input type="text" id="stupanjPrig" /> 
   <form>
     <input id="secondOrder" type="button" value="Izračunaj">
		 <input id="drawChart" type="button"  value="Nacrtaj">
     </form>
      </div>   
       <div id="chartContainer" style="height: 360px; width: 1100px;">


        
		
					
</html>

JavaScript

// Write JavaScript here
window.onload = (function () {
    var famname, T, K, y, M;
		var chart, dps = [];
   	//Initializing chart on window.onload
    
   chart = new CanvasJS.Chart("chartContainer",
    {
    	zoomEnabled: true,
      zoomType: "xy",
      title:{
      	text: "Sustav drugog reda"
     },
       data: [
      {
        type: "spline",
        dataPoints: dps
      }
      
      ]
    });
    
		// Calculate x and y values    
    document.getElementById("secondOrder").onclick = function() { 
      famname = new Array(100);
      T = document.getElementById("vremKonst").value;
      z = document.getElementById("stupanjPrig").value;
      var wn,x,l,wd,d,r,na,nak,u1,u2,s1,s2;
      wn=1/T;
      
      for(t=0;t<100;t+=2.5)
      {
        if(z===0)
        {	
          x=wn*t;
          y=1-Math.cos(x);
          famname[t]=y;
        }
        if(z==1)
        {
          x=-wn*t;
          y=(1-Math.exp(x)*(1-x));
          famname[t]=y;
        }
        if(z<0)
        {
          r=wd*t;
          d=1-(z*z);
          wd=wn*Math.sqrt();
          l=wn*t*z;
          y=(1-Math.exp(-l)*(Math.cos(r)+((z*wn)/wd)*Math.sin(r)));
          famname[t]=y;
        }
        else
        {
          
          na=(z*z)-1;
          nak=Math.sqrt(na);
          s1=wn*(-z+nak);
          s2=wn*(-z-nak);
          u1=s1*t;
          u2=s2*t;
          y=(1+(1/na)*(s2*Math.exp(u1))-s1*Math.exp(u2));
          famname[t]=y;
        }
       
      }
      
      var vrijed = new Array(100);
      for(p=0;p<100;p++)	{
        vrijed[p]=p;
      }

      //updating chart dataPoints 
      dps = [];      
      for(var i = 0, j=0; j < famname.length; i++, j+= 2.5) {
        dps.push({ x: vrijed[i], y: famname[j] });
      }
      chart.options.data[0].dataPoints = dps;
    } 
	
  
		// draw chart
    document.getElementById("drawChart").onclick = function () {
        chart.render();
    }

})();