数学式:y=Asin(ωx+φ)+k
样例:http://www.zhaojz.com.cn/demo/draw7.html
JS函数的声明:
//画正弦曲线 //dot 原点 //amplitude 振幅 -- A //initialPhase 初相 -- φ //setover 偏距 -- k //palstance 角速度 -- ω //len 周期数 function drawSinusoid(dot, amplitude,initialPhase,palstance,setover, len, opts){ var color = opts&&opts.color?opts.color:"DarkRed"; //曲线的颜色 var max = len*2*Math.PI/w; //x的最大值 //var x = -2*Math.PI/w/3; var x = 0; //x的初值 var pre = [dot[0]+x, dot[1]+(amplitude*Math.sin(palstance*x+initialPhase)+setover)]; //y的初值 for(;x < max;x+=5){ //每五个单位画一条线 var cur = [dot[0]+x, dot[1]+(amplitude*Math.sin(palstance*x+initialPhase)+setover)]; drawLine(pre, cur, {color: color}); // 画线 pre = cur; } var d = Math.PI/(2*w); for(var x =0;x < max;x+=d){//描点 var cur = [dot[0]+x, dot[1]+(amplitude*Math.sin(palstance*x+initialPhase)+setover)]; drawPoint({ pw:3,ph:3,color:‘DarkRed‘,point: cur }); } var pend = [dot[0]+max, dot[1]+(amplitude*Math.sin(palstance*max+initialPhase)+setover)]; drawPoint({ pw:3,ph:3,color:‘DarkRed‘,point: pend }); drawLine(pre, pend); }
附上样例:http://www.zhaojz.com.cn/demo/draw4.html
时间: 2024-11-05 10:27:05