I am trying to edit this spectrum abit i want to plot some boxes at 100 M and 120 M. but i am unable to do till now.

I tried as pass data to addData -> drawSpectrum but wasnot able to do so. can some one guild me any way ?

Source Code

my Main reason for failture was that i wasnotable to know how he was ploting data at specfic coordainte in spectrum. Any one guide me please. thank you

Spectrum.prototype.drawSpectrumFoi = function(bins) {

    if (bins.length>0){
        foiDataList=bins;
        recFoiList=true;

        if(recFoiList == true){
            for (var i=0;i<foiDataList.length; i++){

                var y = this.spectrumHeight - 1 - this.squeeze(foiDataList[i], 0, this.spectrumHeight);
                var peakY = this.squeeze(foiDataList[i], 0, this.spectrumHeight);
        
                if (y > this.spectrumHeight - 1) y = this.spectrumHeight - 1;
                if (y < 0) y = 0;
                if (i == 0) this.ctx.lineTo(-1 + this.offset, y); //responsible for height of green line 
        
                // green lines are created here ayaz

                this.ctx.lineTo(i + this.offset, y);
            }

        }

    }else{
        recFoiList=false;
    }
    
        
}