anchor.diff:        input#maxIntensity(type="number")
       .form-group(title="Radius of center of points in pixels.")
         label(for="radius") Radius
  -      input#radius(type="number" placeholder="25")
  +      input#radius(type="number" placeholder="25" min=1)
       .form-group(title="Radius of blur around points in pixels.")
         label(for="blurRadius") Blur Radius
  -      input#blurRadius(type="number" placeholder="15")
  +      input#blurRadius(type="number" placeholder="15" min=0)
       .form-group(title="Color Gradient.  Entries with intensities of 0 and 1 are needed to form a valid color gradient.")
         label Color Gradient
         table.gradient
  
positive.code:           th(title="Alpha channel, 0 to 1") A
          tr
            td
              input#gradI1(type="number")
            td
              input#gradR1(type="number")
            td
              input#gradG1(type="number")
            td
              input#gradB1(type="number")
            td
              input#gradA1(type="number")
          tr
            td
              input#gradI2(type="number")
            td
              input#gradR2(type="number")
            td
              input#gradG2(type="number")
            td
              input#gradB2(type="number")
            td
              input#gradA2(type="number")
          tr
            td
              input#gradI3(type="number")
            td
              input#gradR3(type="number")
            td
              input#gradG3(type="number")
            td
              input#gradB3(type="number")
            td
              input#gradA3(type="number")
          tr
            td
              input#gradI4(type="number")
            td
              input#gradR4(type="number")
            td
              input#gradG4(type="number")
            td
              input#gradB4(type="number")
            td
              input#gradA4(type="number")
          tr
            td
              input#gradI5(type="number")
            td
              input#gradR5(type="number")
            td
              input#gradG5(type="number")
            td
              input#gradB5(type="number")
            td
              input#gradA5(type="number")
          tr
            td
              input#gradI6(type="number")
            td
              input#gradR6(type="number")
            td
              input#gradG6(type="number")
            td
              input#gradB6(type="number")
            td
              input#gradA6(type="number")
  
  
negative.code:       span#points-loaded
      .form-group(title="Number of points.  Leave blank for the entire original data set.  If a smaller number, only a subset of points will be shown.  If a larger number, some of the data will be duplicated with random offsets.")
        label(for="points") Number of Points
        input#points(type="number" min="1" step="100")
        span#points-shown
      .form-group(title="Delay between movement and heatmap recalculation in milliseconds.")
        label(for="updateDelay") Update Delay (ms)
        input#updateDelay(type="number" placeholder="50" min=0)
      .form-group(title="Opacity of heatmap layer (0 to 1).")
        label(for="opacity") Opacity
        input#opacity(type="number" placeholder="0.75" min=0 max=1 step=0.05)
      .form-group(title="Value to map to minimum intensity.  Leave blank to auto calculate.")
        label(for="minIntensity") Min. Intensity
        input#minIntensity(type="number")
  