       el_yAxis = plotSvg.select ".axis.y"
       yLabel = plotSvg.select ".label.y text"
       xLabel = plotSvg.select ".label.x text"
+      wavelengthLabel = plotSvg.select ".wavelength.interactive"
+
 
       # slider stuff
       slide = d3.behavior.drag()

        solution = plancksLaw TEMPERATURE, WAVELENGTH
        slideHandle.attr transform: "translate(0, #{ sliderScale TEMPERATURE })"
        handleLabel.text TEMPERATURE
        handleSolution.text if solution[1] then expwn solution[1] else ""
        plots.selectAll '.series.interactive'
          .data [series]
          .call plotSeries
          .classed interactive: true
          .select "path"
            .style color: "black"

        solutions.selectAll '.solution.interactive'
          .data [solution.solution]

                .classed unit: true
                .text " [µ]"

          plotSvg.append "g"
            .classed wavelength: true, interactive: true
            .attr "text-anchor": "middle"
            .append "text"


      plots = plotSvg.select ".plots"
      solutions = plots.select ".solutions"
