diff --git a/dist/gauge.min.js b/dist/gauge.min.js
index ad5fe44..993df9e 100644
--- a/dist/gauge.min.js
+++ b/dist/gauge.min.js
@@ -1 +1 @@
-'use strict';class Gauge{constructor(configuration){const config={size:200,margin:10,minValue:0,maxValue:10,majorTicks:5,lowThreshhold:3,highThreshhold:7,scale:'linear',lowThreshholdColor:'#009900',defaultColor:'#ffe500',highThreshholdColor:'#cc0000',transitionMs:1000,displayUnit:'Value'};this.arcPadding=15;this.arcWidth=20;this.labelInset=10;this.minAngle=-90,this.maxAngle=90,this.angleRange=this.maxAngle-this.minAngle;this.config=Object.assign(config,configuration);this._config(configuration)}_config(){const pointerWidth=6;const pointerTailLength=5;const pointerHeadLength=this._radius()-this.labelInset;this.lineData=[[pointerWidth/2,0],[0,-pointerHeadLength],[-(pointerWidth/2),0],[0,pointerTailLength],[pointerWidth/2,0]];if(this.config.scale=='log'){this.scale=d3.scaleLog().range([0,1]).domain([this.config.minValue,this.config.maxValue])}else{this.scale=d3.scaleLinear().range([0,1]).domain([this.config.minValue,this.config.maxValue])}const colorDomain=[this.config.lowThreshhold,this.config.highThreshhold].map(this.scale);const colorRange=[this.config.lowThreshholdColor,this.config.defaultColor,this.config.highThreshholdColor];this.colorScale=d3.scaleThreshold().domain(colorDomain).range(colorRange);let ticks=this.config.majorTicks;if(this.config.scale==='log'){ticks=Math.log10(this.config.maxValue/this.minValue)}this.ticks=this.scale.ticks(ticks);this.threshholds=[this.config.minValue,this.config.lowThreshhold,this.config.highThreshhold,this.config.maxValue].map(d=>this.scale(d));this.arc=d3.arc().innerRadius(this._radius()-this.arcWidth-this.arcPadding).outerRadius(this._radius()-this.arcPadding).startAngle((d,i)=>{const ratio=i>0?this.threshholds[i-1]:this.threshholds[0];return this._deg2rad(this.minAngle+(ratio*this.angleRange))}).endAngle((d,i)=>this._deg2rad(this.minAngle+this.threshholds[i]*this.angleRange))}_radius(){return(this.config.size-this.config.margin)/2}_deg2rad(deg){return deg*Math.PI/180}setConfig(configuration){this.config=Object.assign(this.config,configuration);this._config();return this}render(container,newValue){d3.select(container).selectAll('svg').remove();d3.select(container).selectAll('div').remove();const svg=d3.select(container).append('svg').attr('class','gauge').attr('width',this.config.size+this.config.margin).attr('height',this.config.size/2+this.config.margin);const arcs=svg.append('g').attr('class','arc').attr('transform',`translate(${this._radius()}, ${this._radius()})`);arcs.selectAll('path').data(this.threshholds).enter().append('path').attr('fill',d=>this.colorScale(d-0.001)).attr('d',this.arc);const lg=svg.append('g').attr('class','label').attr('transform',`translate(${this._radius()},${this._radius()})`);lg.selectAll('text').data(this.ticks).enter().append('text').attr('transform',d=>{var newAngle=this.minAngle+(this.scale(d)*this.angleRange);return `rotate(${ newAngle }) translate(0, ${this.labelInset-this._radius()})`}).text(d3.format('1,.0f'));lg.selectAll('line').data(this.ticks).enter().append('line').attr('class','tickline').attr('x1',0).attr('y1',0).attr('x2',0).attr('y2',this.arcWidth+this.labelInset).attr('transform',d=>{const newAngle=this.minAngle+(this.scale(d)*this.angleRange);return `rotate(${ newAngle }), translate(0, ${this.arcWidth-this.labelInset-this._radius()})`}).style('stroke','#666').style('stroke-width','1px');const pg=svg.append('g').data([this.lineData]).attr('class','pointer').attr('transform',`translate(${this._radius()},${this._radius()})`);const pointer=pg.append('path').attr('d',d3.line()).attr('transform',`rotate(${this.minAngle })`);const numberDiv=d3.select(container).append('div').attr('class','number-div').style('width',`${this.config.size-this.config.margin }px`);const numberUnit=numberDiv.append('span').attr('class','number-unit').text(d=>this.config.displayUnit);const numberValue=numberDiv.append('span').data([newValue]).attr('class','number-value').text(d=>d===undefined?0:d);this.pointer=pointer;this.numberValue=numberValue}update(newValue){const newAngle=this.minAngle+(this.scale(newValue)*this.angleRange);this.pointer.transition().duration(this.config.transitionMs).attr('transform',`rotate(${ newAngle })`);this.numberValue.data([newValue]).transition().duration(this.config.transitionMs).style('color',this.colorScale(this.scale(newValue))).tween("",function(d){const interpolator=d3.interpolate(this.textContent,d);const that=this;return function(t){that.textContent=interpolator(t).toFixed(1)}})}}
+'use strict';class Gauge{constructor(configuration){const config={size:200,margin:10,minValue:0,maxValue:10,majorTicks:5,lowThreshhold:3,highThreshhold:7,scale:'linear',lowThreshholdColor:'#009900',defaultColor:'#ffe500',highThreshholdColor:'#cc0000',transitionMs:1000,displayUnit:'Value'};this.arcPadding=15;this.arcWidth=20;this.labelInset=10;this.minAngle=-90,this.maxAngle=90,this.angleRange=this.maxAngle-this.minAngle;this.config=Object.assign(config,configuration);this._config()}_config(){const pointerWidth=6;const pointerTailLength=5;const pointerHeadLength=this._radius()-this.labelInset;this.lineData=[[pointerWidth/2,0],[0,-pointerHeadLength],[-(pointerWidth/2),0],[0,pointerTailLength],[pointerWidth/2,0]];if(this.config.scale=='log'){this.scale=d3.scaleLog().range([0,1]).domain([this.config.minValue,this.config.maxValue])}else{this.scale=d3.scaleLinear().range([0,1]).domain([this.config.minValue,this.config.maxValue])}const colorDomain=[this.config.lowThreshhold,this.config.highThreshhold].map(this.scale);const colorRange=[this.config.lowThreshholdColor,this.config.defaultColor,this.config.highThreshholdColor];this.colorScale=d3.scaleThreshold().domain(colorDomain).range(colorRange);let ticks=this.config.majorTicks;if(this.config.scale==='log'){ticks=Math.log10(this.config.maxValue/this.config.minValue)}this.ticks=this.scale.ticks(ticks);this.threshholds=[this.config.minValue,this.config.lowThreshhold,this.config.highThreshhold,this.config.maxValue].map(d=>this.scale(d));this.arc=d3.arc().innerRadius(this._radius()-this.arcWidth-this.arcPadding).outerRadius(this._radius()-this.arcPadding).startAngle((d,i)=>{const ratio=i>0?this.threshholds[i-1]:this.threshholds[0];return this._deg2rad(this.minAngle+(ratio*this.angleRange))}).endAngle((d,i)=>this._deg2rad(this.minAngle+this.threshholds[i]*this.angleRange))}_radius(){return(this.config.size-this.config.margin)/2}_deg2rad(deg){return deg*Math.PI/180}setConfig(configuration){this.config=Object.assign(this.config,configuration);this._config();return this}render(container,newValue){d3.select(container).selectAll('svg').remove();d3.select(container).selectAll('div').remove();const svg=d3.select(container).append('svg').attr('class','gauge').attr('width',this.config.size+this.config.margin).attr('height',this.config.size/2+this.config.margin);const arcs=svg.append('g').attr('class','arc').attr('transform',`translate(${this._radius()}, ${this._radius()})`);arcs.selectAll('path').data(this.threshholds).enter().append('path').attr('fill',d=>this.colorScale(d-0.001)).attr('d',this.arc);const lg=svg.append('g').attr('class','label').attr('transform',`translate(${this._radius()},${this._radius()})`);lg.selectAll('text').data(this.ticks).enter().append('text').attr('transform',d=>{var newAngle=this.minAngle+(this.scale(d)*this.angleRange);return `rotate(${ newAngle }) translate(0, ${this.labelInset-this._radius()})`}).text(d3.format('1,.0f'));lg.selectAll('line').data(this.ticks).enter().append('line').attr('class','tickline').attr('x1',0).attr('y1',0).attr('x2',0).attr('y2',this.arcWidth+this.labelInset).attr('transform',d=>{const newAngle=this.minAngle+(this.scale(d)*this.angleRange);return `rotate(${ newAngle }), translate(0, ${this.arcWidth-this.labelInset-this._radius()})`}).style('stroke','#666').style('stroke-width','1px');const pg=svg.append('g').data([this.lineData]).attr('class','pointer').attr('transform',`translate(${this._radius()},${this._radius()})`);const pointer=pg.append('path').attr('d',d3.line()).attr('transform',`rotate(${this.minAngle })`);const numberDiv=d3.select(container).append('div').attr('class','number-div').style('width',`${this.config.size-this.config.margin }px`);const numberUnit=numberDiv.append('span').attr('class','number-unit').text(d=>this.config.displayUnit);const numberValue=numberDiv.append('span').data([newValue]).attr('class','number-value').text(d=>d===undefined?0:d);this.pointer=pointer;this.numberValue=numberValue}update(newValue){const newAngle=this.minAngle+(this.scale(newValue)*this.angleRange);this.pointer.transition().duration(this.config.transitionMs).attr('transform',`rotate(${ newAngle })`);this.numberValue.data([newValue]).transition().duration(this.config.transitionMs).style('color',this.colorScale(this.scale(newValue))).tween("",function(d){const interpolator=d3.interpolate(this.textContent,d);const that=this;return function(t){that.textContent=interpolator(t).toFixed(1)}})}}
diff --git a/example.js b/example.js
index 5102b4d..4389e26 100644
--- a/example.js
+++ b/example.js
@@ -5,9 +5,7 @@
 */
 document.addEventListener('DOMContentLoaded', () => {
 
-  // create an Gauge instance with default construct, and set configuration later
-  const powerGauge = new Gauge();
-  powerGuage.setConfig({
+  const powerGauge = new Gauge({
     minValue: 5,
     maxValue: 300000,
     lowThreshhold: 300,
@@ -15,7 +13,7 @@ document.addEventListener('DOMContentLoaded', () => {
     scale: 'log',
     displayUnit: 'Log10(x)'
   });
-  // create an Guage instance with pass-in configuration object
+
   const powerGauge2 = new Gauge({
     minValue: 10,
     maxValue: 60,
diff --git a/source/gauge.js b/source/gauge.js
index 48245f4..b8ae12d 100644
--- a/source/gauge.js
+++ b/source/gauge.js
@@ -28,10 +28,9 @@ class Gauge {
     this.maxAngle = 90,
     this.angleRange = this.maxAngle - this.minAngle;
 
-    if (configuration !== undefined) {
-      this.config = Object.assign(config, configuration);
-      this._config(configuration);
-    }
+    this.config = Object.assign(config, configuration);
+    this._config();
+
   }
 
   _config() {
@@ -69,7 +68,7 @@ class Gauge {
 
     let ticks = this.config.majorTicks;
     if (this.config.scale === 'log') {
-      ticks = Math.log10(this.config.maxValue/this.minValue);
+      ticks = Math.log10(this.config.maxValue/this.config.minValue);
     }
     this.ticks = this.scale.ticks(ticks);