Added documentation for Spatial Plot Tool. Fixes #5281

  </brief>

  <description>

    This program will display cubes and allow for interactive analysis.

    <p>

      This program will display cubes and allow for interactive analysis. It involves the 

      implementation of a number of individual tools.

    </p>

    <h3>Spatial Plot Tool</h3>

    <p>

      This tool is used for analyzing pixel DN values for a manual selection made. It works with two 

      different modes: linear and rotated rectangle. It is also capable of handling three different 

      modes of interpolation: Nearest Neighbor, BiLinear and Cubic Convolution. 

    </p>

    <h4>Linear</h4>

    <p>

      This is the simpler of the two modes for the Spatial Plot Tool. It invloves the drawing of a 

      line across an opened cube. The selection is started by clicking and holding the mouse where 

      you would like to start your calculations, at which point you may drag the mouse in any 

      direction and release the click to extablish the end of your selection.

    </p>

    <p>

      The tool calculates the length of the line in pixels, rounding to the nearest full pixel 

      value. It then divides the actual length of the line by this rounded length to achieve a 

      step-size. <strong>Please note:</strong> this step size may be slightly bigger or smaller 

      than a pixel length, but this difference becomes neglibible for larger selections. For 

      example, if the length of the drawn line was 6.36 pixels, the tool would round the length to 

      6 and the step-size would be 6.36/6 (or 1.06).

    </p>

    <p>

      A plot window will be generated with the calculated DN values of the pixels. The first value 

      to be calculated would be the value where the original mouse click was made. The tool then 

      calculates the value along the line at each step-sized increment until it reaches where the 

      mouse-click was released. This means that for a rounded length of 6, the plot would show a 

      total of 7 plotted DN values.

    </p>

    <image src="assets/image/LinearSelection.png" height="400" />

    <image src="assets/image/LinearPlot.png" height="400" />

    <p>

      The images above include an example of the line as drawn in the cube view as well as the 

      associated plot window. Marking has been added to dilineate where mouse clicks were made and 

      the DN values were calculated. The mouse was first clicked at dileneation marked "1" on the 

      cube, and was released at "4". The number from the cube view correlates with the "Pixel 

      Number" on the plot.

    </p>

    <h4>Rotated Rectangle</h4>

    <p>

      The more complex of the two modes for the Spatial Plot Tool, this mode involves drawing a 

      rectangle across an opened cube. The selection is started by clicking and holding the mouse 

      where you would like to start your calculations, at which point you may drag the mouse in any 

      direction and release the click to extablish one edge of your selection. You may then 

      drag the mouse away from this original line to expand in the other direction. A single mouse 

      click establishes your final selection. <strong>Please note:</strong> the tool will lock 

      angles to be perpendicular and so your selections will always be a perfect rectangle.

    </p>

    <p>

      Similar to the linear mode of this tool, the lengths of the lines in pixels are rounded to the 

      nearest full pixel value, and then the lengths are divided by this rounded length to establish 

      a step-size. (Please refer to the Linear section for an example.) <strong>Please note:</strong>

      the step-size along one edge of the selection may not be the same as the step-size of the 

      perpendicular edge. This becomes neglibile for larger selections.

    </p>

    <p>

      A plot window will be generated with the calculated DN values. This is done by calculating the 

      value where the original mouse click was made, then continuing in the direction of that 

      first-drawn line, calculating the DN value at each step-sized increment until it reaches where 

      the original mouse-click was released. The tool will then calculate the average of these 

      values. This average becomes the first value in the plot.

    </p>

    <p>

      The tool will then shift a step-size along the perpendicular edge, and calculate the average DN 

      value along a line running parallel to the first-drawn line. This average becomes the second 

      value in the plot. The tool continues this pattern until it has reached the opposite edge of 

      the rectangle as the first-drawn line.

    </p>

    <p>

      The following example illustrates this process.

    </p>

    <image src="assets/image/RRSelection.png" height="400" />

    <image src="assets/image/RRSelectionMarked.png" height="400" />

    <image src="assets/image/RRPlot.png" height="400" />

    <p>

      The image to the left is the original selection as seen in the cube view, and the image 

      in the middle is the same view that has been marked for reference purposes. Finally, the image 

      to the right is the associated plot window. The original mouse click was made at delineation 

      "1" within the cube view, the original mouse release was made at "5", and the final 

      mouse click was made at "25". The Spatial Plot Tool calculates the average of the DN values at 

      dilineations 1-5, and this value is stored as "Pixel Value" 1 in the plot window, while the 

      averages of 6-10 are stored in 2, 7-15 are stored in 3, 16-20 are stored in 4, and finally

      21-25 are stored in 5. 

    </p>

    <h4>Interpolations</h4>

    <p>

      Spatial Plot Tool makes use of Nearest Nighbor, BiLinear and Cubic Convolution interpolations 

      when calculating the DN values at particular points. <strong>Do be aware that when the tool is 

      calculating a DN value at a particular point, it is calculating the interpolated DN value at 

      that point. This may lead to confusion without a proper understanding of interpolations.</strong>

    </p>

  </description>

  <category>

      Readded help menu for the 2D and 3D plot tools. Now properly display in both tools.

      Fixes #2126.

    </change>

    <change name="Summer Stapleton" date="2018-03-14">

      Included documentation for Spatial Plot Tool. Fixes #5281.

    </change>

  </history>

</application>