In slpmap, added the FILE option to the PIXRES parameter. This allows the user...

#include <cmath>

#include "Isis.h"

#include <cmath>

#include "Angle.h"

#include "Camera.h"

#include "Distance.h"

#include "Latitude.h"

#include "Longitude.h"

#include "ProcessByBoxcar.h"

#include "Projection.h"

#include "SurfacePoint.h"

#include "Target.h"

#include "UniversalGroundMap.h"

using namespace std;

  // Create output cube

  Cube *ocube = p.SetOutputCube("TO");

  PvlObject &lblCubeObj = ocube->label()->findObject("IsisCube");

  lblCubeObj.addGroup( PvlGroup("BandBin") );

  PvlGroup &bbGroup = lblCubeObj.findGroup("BandBin");

      g_groundMap = new UniversalGroundMap(*icube);

      p.StartProcess(createSlpCubeAutomatic);

    }

    else {

      if (ui.GetString("PIXRES") == "FILE") {

        g_groundMap = new UniversalGroundMap(*icube);

        g_resolution = g_groundMap->Resolution();

      }

      else {

        g_resolution = ui.GetDouble("RESOLUTION");

      }

      g_conversionFactor = ui.GetDouble("CONVERSION");

      p.StartProcess(createSlpCube);

    }

    }

  }

  // Cleanup

  delete g_groundMap;

  g_groundMap = 0;

    return;

  }

  // Save off the radius at the center of the current 3x3

  Distance centerRadius;

  try {

    Distance(in[4], Distance::Meters);

  }

<application name="slpmap" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://isis.astrogeology.usgs.gov/Schemas/Application/application.xsd">

  <brief>

    Creates cubes that have slope data or aspect data

    Create slope, aspect, or percent slope data cube.

  </brief>

  <description>

    This program will compute the slope or aspect of a cube.  Typically a digital terrain model with DN

    values representing the radius of a target body is

    given as the input but other non-radius datasets can be provided. Horne's algorithm is used

    to compute the slope or aspect. A 3x3 kernel:<pre>

    This program creates a new cube containing slope (radians, degree,s or percent) or aspect

    (radians, degrees) data from an input cube. This program computes the slope and aspect of

    an input cube and outputs the results. An individual slope, aspec, or percent slope cube can

    be rendered using this program.

    <p>Data requirements to run slpmap:

      <ul>

        <li> A digital terrain model (DTM) with DN values representing the radius or elevation of a

             target body, or </li>

        <li> Any ISIS cube that is a level 1 or level 2 image (can be multiband).</li>

      </ul>

    </p>

    Horne's algorithm is used to compute the slope or aspect. A 3x3 kernel:

    <pre>

      A  B  C

      D  E  F

   G  H  I</pre>

   is convolved through the image and each output pixel is computed as follows:

      G  H  I

    </pre>

    Each output pixel is computed as follows:

    <pre>

      <b>SLOPE EQUATION</b>

      [dz/dx] = ((C + 2F + I) - (A + 2D + G)) / (8 * X_PIXEL_RESOLUTION)

      slope = ATAN ( SQRT ( [dz/dx]^2 + [dz/dy]^2 ) )

      percentslope = slope / 90

    </pre>

    The slope equation above assumes the pixels are not square: hence X_PIXEL_RESOLUTION and

    Y_PIXEL_RESOLUTION. That is, the x distance across the pixel is not equal to the y distance

    form top to bottom of the pixel.

    <pre>

      <b>ASPECT EQUATION</b>

      [dz/dx] = ((C + 2F + I) - (A + 2D + G)) / 8

      [dz/dy] = ((G + 2H + I) - (A + 2B + C)) / 8

      aspect = 90 - ATAN2 ([dz/dy], -[dz/dx])

      if (aspect < 0) then aspect = aspect + 360

    </pre>

  Slope is typically betwen 0 and 90 degrees, flat to vertical slope,

  respectively. The aspect represents the direction (0 to 360) of the slope in pixel space.  

  From the center pixel (E), 0 degrees is straight towards B, 45 is towards C, 90 is towards F,

  135 is towards I, 180 is towards H, and so on.  The may choose to output the slope in

  radians, degrees, or percent slope, the aspect in degrees or radians.

    <p><b>Slope:</b>

      Slope is typically between 0 and 90 degrees, were 0 is flat and 90 is vertical.Slope may be

      output in radians, degrees, or percent slope.

    </p>

    <p><b>Aspect:</b>

    The aspect represents the direction or 0 to 360 degrees of the slope in pixel space (see

    figure below). From the center pixel (E), 0 degrees is straight towards B (generally north),

    45 is towards C, 90 is towards F, 135 is towards I, 180 is towards H, and so on.

    <pre><b>

      A  B  C

      D  E  F

      G  H  I

    </b></pre>

    </p>

    <p>

    The slope equation above assumes the pixels are not square: hence X_PIXEL_RESOLUTION and

    Y_PIXEL_RESOLUTION.  That is, the x distance across the pixel is not equal to the y distance 

    from top to the bottom of the pixel.   By default the program will attempt to remove any

    scaling differences by using the map projection information (PIXRES=AUTOMATIC).  This

    computation is done at every pixel so the correct x-to-y ratio is computed.  This

    is important for global maps where the x/y ratio deviates with distance from the latitude

    and/or longitude of true scale in the map projection. If the image lacks a map projection

    then the user must provide the pixel resolution via PIXRES=USER. For this option the pixels are

    assumed to be square.

    The user then provides a single value (RESOLUTION) that will be applied to all pixels in the

    image and in both directions.  

      <b>Scale Construction:</b>

      By default, the program will attempt to remove any scaling differences by using the map

      projection information (PIXRES=AUTOMATIC). This computation is done at every pixel so the

      correct x-to-y ratio is computed. This is important, for example, for global maps where

      the x/y ratio deviates with distance from the latitude and/or longitude of true scale in

      a map projection. This only works for radius DTMs.

    </p>

    <p>

      <b>What if the input cube Z units are in elevation values instead of radius values?</b>

    </p>

    <p>

      The default setting PIXRES=AUTOMATIC will not work. You will need to set PIXRES=FILE

      (recommended for a map projected file) or  PIXRES=USER. Note: unlike PIXRES=AUTOMATIC,

      these later two methods do not correct for distortions int he map projection. They will

      return good results for smaller regious when the map projection is defined to minimixe

      distortions (e.g. LROC NAC or HIRISE sereo DTMs).

    </p>

    <p>

      <b>What if the input cube is not map projected?</b>

    </p>

    <p>

    The second assumption is the xy units are the same as the z (pixel) units. By default

    the program assumes the units are the same, but allows the user to scale the z units to the xy

    units using the CONVERSIONFACTOR parameter if the PIXRES=USER option is being used.

      If the image lacks a map projection,you must provide the pixel resolution via PIXRES=USER

      (for this option the pixels are assumed to be square). You must also provide a single value

      using the RESOLUTION parameter that will be applied to all pixels in the image and in both

      directions.

    </p>

    <p>

      <b>What if the xy units are not the same as the z units?</b>

    </p>

    <p>

      The program assumes the xy units are the same as the z (pixel) units. By default

      the program assumes the units are the same, but allows you to scale the z units to the xy

      units using the CONVERSIONFACTOR parameter if the PIXRES=USER option is selected.

    </p>

  </description>

  <history>

      Added a test to the CONVERSION=AUTOMATIC option so DNs in the cube with negative values

      will cause a better error to be shown. Added a BANDBIN group to the output cube labels.

    </change>

    <change name="Kimberly Oyama" date="2014-03-28">

      Added the FILE option to the PIXRES parameter. This allows the user to specify that the

      pixel resolution from the input cube's projection should be used. Updated the documentation.

      Fixes #1764.

    </change>

  </history>

  <category>

          Input cube

        </brief>

        <description>

          Use this parameter to select the input cube. All bands of the cube within the file

          will have the algorithm applied.

          Use this parameter to select the input cube.The algorithm is applied to all bands of a

          multiband cube.

        </description>

        <filter>

          *.cub

          Output cube

        </brief>

        <description>

          Use this parameter to define the filename of the resultant slope or aspect cube

          Use this parameter to define the filename of the resultant slope, aspect, or percent

          slope cube.

        </description>

      </parameter>

    </group>

    <group name="Output Options">

      <parameter name="OUTPUT">

        <type>string</type>

        <brief>Type of output requested, slope, aspect, or percent slope</brief>

        <brief>Output type: slope, aspect, or percent slope</brief>

        <default><item>SLOPE</item></default>

        <description>

          This determines the type of output pixels that will be created. The output file will

          This specifies the type of output pixels that will be created. The output file will

          contain either slope, aspect, or, percent slope.

        </description>

      	<list>

        </description>

        <list>

          <option value="AUTOMATIC">

            <brief>Automatically compute the resolution using the map projection</brief>

            <brief>Automatically compute the resolution per pixel using the map projection</brief>

            <description>

              The program will use the map projection to automatically compute the resolution

              (X and Y) of each pixel in order to ensure the slope is computed properly.

              The program will use the map projection to compute the resolution (X and Y) of each

              pixel to ensure the slope is computed properly. This option requires that the input

              cube be a radius file, a cube in which the DN values represent the radius of the

              target at that point (no negative DN values).

            </description>

            <exclusions>

              <item>RESOLUTION</item>

              <item>CONVERSION</item>

            </exclusions>

          </option>

          <option value="FILE">

            <brief>Pixel Resolution of FROM cube's projection.</brief>

            <description>

              The input cube must be projected if this option is selected. The pixel resolution

              will come from the mapping group of the input cube. 

            </description>

            <exclusions>

              <item>RESOLUTION</item>

            </exclusions>

          </option>

          <option value="USER">

            <brief>User defined pixel resolution</brief>

            <description>

        <brief>Conversion from z units to spatial units</brief>

        <default><item>1.0</item></default>

        <description>

          Since the slope algorithm depends on cancelling out the units, the

          conversion factor from the z vertical (input pixel) units to the xy horizontal (spatial)

          units needs to be considered.

          This parameter is a multiplicative factor for the resolution. It is used to convert the

          spatial units (pixels) to the correct distance units. Since the slope algorithm depends

          on cancelling out the units, the conversion factor from the z vertical (input pixel)

          units to the xy horizontal (spatial) units needs to be considered.

          For example, if the

          xy units are in meters and the z units are in kilometers the unit conversion factor

          should be 1000 as we are converting z kilometers to xy meters.  

          For example, if the xy units are in meters and the z units are in kilometers the unit

          conversion factor should be 1000 as we are converting z kilometers to xy meters.

          The default presumes the units are the same.

        </description>

APPNAME = slpmap

slpmapTruth2.cub.TOLERANCE = .000001

include $(ISISROOT)/make/isismake.tsts

commands:

	$(APPNAME) from=$(INPUT)/input.cub to=$(OUTPUT)/slpmapTruth.cub \

	  output=slope pixres=file > /dev/null;