This page was created by the IDL library routine `mk_html_help2`.

Last modified: Thu Oct 9 18:17:23 2025.

# Directory Listing of Routines

# general/science/spd_slice2d/core

- SPD_CAL_ROT
  Returns a rotation matrix that rotates v1,v2 to the x-y plane
- SPD_PART_VIS
- SPD_SLICE1D_PLOT
  Create 1D plot from a 2D particle slice; note that:
- SPD_SLICE2D_2DI
- SPD_SLICE2D_3DI
- SPD_SLICE2D_CHECKBINS
- SPD_SLICE2D_COLLATE
- SPD_SLICE2D_CONST
- SPD_SLICE2D_CUSTOM_ROTATION
- SPD_SLICE2D_GEO
- SPD_SLICE2D_GET_DATA
- SPD_SLICE2D_GET_EBOUNDS
- SPD_SLICE2D_GET_SPHERE
- SPD_SLICE2D_INTRANGE
- SPD_SLICE2D_NEAREST
- SPD_SLICE2D_ORIENTSLICE
- SPD_SLICE2D_RLOG
- SPD_SLICE2D_ROTATE
- SPD_SLICE2D_S2C
- SPD_SLICE2D_SMOOTH
- SPD_SLICE2D_SUBTRACT
- SPD_SLICE2D_TRANSLATE
- SPD_TPLOT_AVERAGE

# Routine Descriptions

## SPD_CAL_ROT

[Next Routine] [List of Routines]

    FUNCTION:
     spd_cal_rot(v1,v2)

    INPUT:
     v1: 3 component vector,
     v2: 3 component vector,

    PURPOSE:
     Returns a rotation matrix that rotates v1,v2 to the x-y plane
     v1 is rotated to the x-axis and v2 into the x-y plane

    NOTES:
     Function normally called by "add_df2d.pro" to rotate
     velocities into the plane of Vsw and B

    CREATED BY:
     J.McFadden

    LAST MODIFICATION:
     95-9-13   J.McFadden
     15-9-08   A.Flores - forked

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_cal_rot.pro $

(See general/science/spd_slice2d/core/spd_cal_rot.pro)

## SPD_PART_VIS

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_part_vis

    Purpose:
      View data from 3D distribution structures in 3 dimensions.
      This is primarily a diagnostic tool.

    Calling Sequence:
      spd_part_vis, input [,trange=trange] [,samples=samples]
                          [,time=time [,window=window [,/center_time]]
                          [/zeros]

    Input:
      input:  Structure array or scalar pointer to structure array
      samples:  Specify # of distributions to plot (default=1)
      trange:  Plot distribution(s) within this time range
      time:  Plot distribution(s) closest to this time
      window:  Use a time range of this width (sec) from TIME
      center_time:  TIME is the center of the window instead of the start
      zeros:  Flag to plot zeros instead of nonzero data

    Output:
      fail:  Returns message in case of error

    Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-12-09 18:11:14 -0800 (Wed, 09 Dec 2015) $
    $LastChangedRevision: 19562 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_part_vis.pro $

(See general/science/spd_slice2d/core/spd_part_vis.pro)

## SPD_SLICE1D_PLOT

[Previous Routine] [Next Routine] [List of Routines]

     PROCEDURE:
      spd_slice1d_plot

     PURPOSE:
      Create 1D plot from a 2D particle slice; note that:
       1) if the 'value' argument is a scalar, this provides
          a cut through the distribution at the nearest point
          in that direction
       2) if the 'value' argument is an array, this sums over
          the values between the min and max of the array

     EXAMPLES:
      MMS> spd_slice1d_plot, slice, 'x', 0.0, title='Vx at Vy=0'

      or

      MMS> spd_slice1d_plot, slice, 'x', [-1000, 1000], title='Vx at Vy=[-1000, 1000] (summed)'

     see: projects/mms/examples/advanced/mms_slice2d_1d_plot_crib.pro for more examples

     INPUT:
      slice: slice returned by spd_slice2d
      direction: axis to plot - 'x' or 'y'
      value: if direction is 'x', this is the y-value to create a 1D plot at;
             can also be a range of values, e.g., [-1000, 1000] to sum over
             the y-values from -1000 to +1000

     KEYWORDS:
       accepts most keywords accepted by the PLOT procedure

     NOTES:
       work in progress! please send bugs/problems/complaints/etc to egrimes@igpp.ucla.edu

    $LastChangedBy: egrimes $
    $LastChangedDate: 2018-11-30 13:11:06 -0800 (Fri, 30 Nov 2018) $
    $LastChangedRevision: 26211 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice1d_plot.pro $

(See general/science/spd_slice2d/core/spd_slice1d_plot.pro)

## SPD_SLICE2D_2DI

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_2di.pro

    Purpose:
      Helper function for spd_slice2d.  Produces slice by interpolating projected data.
      This code is meant to preserve the functionality of thm_esa_slice2d.

    Input:
      datapoints:  N elements array of data values
      xyz:  Nx3 array of vectors
      resolution:  Resolution (R) in points of each dimension of the output
      thetarange:  Elevation range about the slice plane used to select points for interpolation
      zdirrange:  Linear range perpendicular to the slice plane used to select points
                  for interpolation (if thetarange is not specified).

    Output:
      slice_data:  RxR array of interpolated data points
      x/ygrid:  R element array s of x and y axis values corresponding to slice_data

    Notes

    $LastChangedBy: egrimes $
    $LastChangedDate: 2020-05-14 09:56:46 -0700 (Thu, 14 May 2020) $
    $LastChangedRevision: 28690 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_2di.pro $

(See general/science/spd_slice2d/core/spd_slice2d_2di.pro)

## SPD_SLICE2D_3DI

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_3di.pro

    Purpose:
      Helper function for spd_slice2d.  Produces slice by interpolating the
      entire data set in three dimensions then extracting a plane of values
      using the nearest neighbor.

    Input:
      datapoints:  N elements array of data values
      xyz:  Nx3 array of vectors
      resolution:  Resolution (R) in points of each dimension of the output

    Output:
      slice_data:  RxR array of interpolated data points
      x/ygrid:  R element array s of x and y axis values corresponding to slice_data

    Notes

    $LastChangedBy: adrozdov $
    $LastChangedDate: 2018-05-21 12:46:11 -0700 (Mon, 21 May 2018) $
    $LastChangedRevision: 25240 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_3di.pro $

(See general/science/spd_slice2d/core/spd_slice2d_3di.pro)

## SPD_SLICE2D_CHECKBINS

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_checkbins

    Purpose:
      Checks if two particle distribution structures have identical
      energy, phi, theta, and mass values.

    Input:
      dist1: 3D particle data structure
      dist2: 3D particle data structure

    Output:
      return value: (bool) 1 if all fields match or second input
                           is undefined, 0 otherwise

    Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_checkbins.pro $

(See general/science/spd_slice2d/core/spd_slice2d_checkbins.pro)

## SPD_SLICE2D_COLLATE

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
     spd_slice2d_collate

    Purpose:
     Collate data aggregated as spd_slice2d_get_data loops over input
     Data aggregation continues until a change in energy or angle
     bins occurs (mode change or other) or aggregation completes.
     At those points this procedure is called to average the data,
     concatenate data to output variables, and clear the appropriate
     variables for the next loop.

    Input:
      data_t: summed data for all bins
      weight_t: summed weights for all bins

      rad_in: radial coords
      phi_in: phi coords
      theta_in: theta coords

      dr_in: radial bin widths
      dp_in: phi bin widths
      dt_in: theta bin widths

    Output:
      data_out: averaged data

      rad_out: radian coords
      phi_out: phi coords
      theta_out: theta corods

      dr_out: radian bin widths
      dp_out: phi bin widths
      dt_out: theta bin widths

      fail:  string output message, set if error occurs

    Notes:

    $LastChangedBy: egrimes $
    $LastChangedDate: 2018-03-26 12:33:55 -0700 (Mon, 26 Mar 2018) $
    $LastChangedRevision: 24954 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_collate.pro $

(See general/science/spd_slice2d/core/spd_slice2d_collate.pro)

## SPD_SLICE2D_CONST

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_const

    Purpose:
      Store constants in a single place for consistency

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_const.pro $

(See general/science/spd_slice2d/core/spd_slice2d_const.pro)

## SPD_SLICE2D_CUSTOM_ROTATION

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_custom_rotation

    Purpose:
      Retrieve a user-provided rotation matrix and apply to data as needed.

    Input:
      custom_rotation:  3x3 rotation matrix or name to tplot variable containing such matrix
      trange:  time range of the slice, tplot vars will be averaged over this range
      determ_tolerance: acceptable tolerance for determ=1, defaults to 1e-6

    Output:
      matrix:  the transformation matrix

    Input/Output (transformed if present):
      vectors:  array of particle 3 vectors
      bfield: b field vector
      vbulk: bulk velocity vector
      sunvec: sun position vector

    Notes:

    $LastChangedBy: jimm $
    $LastChangedDate: 2020-05-04 13:37:27 -0700 (Mon, 04 May 2020) $
    $LastChangedRevision: 28663 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_custom_rotation.pro $

(See general/science/spd_slice2d/core/spd_slice2d_custom_rotation.pro)

## SPD_SLICE2D_GEO

[Previous Routine] [Next Routine] [List of Routines]

     Name:
       spd_slice2d_geo.pro

     Purpose:
       Helper function for spd_slice2d.pro

       Produces slices showing each bin's boundaries by assigning
       each bin's value to all points on the slice plane that
       fall within that bin's boundaries.

       This is essentially a hack to allow plotting of bin boundaries
       with contour instead of creating a new plotting routine.

     Input:
       data: N element array of data values
       rad: N element array of radial values
       phi: N element array of phi values
       theta: N element array of theta values

       dp: N element array of phi ranges
       dt: N element array of theta ranges
       dr: N element array of velocity ranges

       resolution: Single value (R) giving the number of points in each
                   dimension of the slice
       average_angle: Two element array specifying an angle range over which
                      averaging will be applied. The angle is measured
                      from the slice plane and about the slice's x-axis.
                        e.g. [-25,25] will average data within 25 degrees
                             of the slice plane about it's x-axis
       sum_angle: (geometric interpolation only)
                   Two element array specifying an angle range over which
                   summing will be applied. The angle is measured
                   from the slice plane and about the slice's x-axis.
                     e.g. [-25,25] will sum data within 25 degrees
                     of the slice plane about it's x-axis

       custom_matrix: Rotation matrix from native -> user specified coordinates
                      (applied first)
       rotation_matrix: Rotation matrix from given coordinates to built in
                        rotated coordinates, e.g. GSM -> BV, perp_xy
                        (applied second)
       slice_matrix: Rotation matrix from specified coords/rotation into
                      the slice plane's final coordinates as defined by
                      the user specified normal and x projection.
                      (applied last)
       shift: Vector by which the slice should be shifted (e.g. bulk velocity subtraction).
              The slice plane will be shifted by the z value and the x & y values will be
              subtracted from the corresponding axes' grids (it should already be in the
              slice plane's coordinates).

     Output:
       xgrid: R element array of x-axis values for the slice
       ygrid: R element array of y-axis values for the slice
       slice: RxR element array containing the slice data

     Other Keywords:
       msg_obj: dprint display object reference
       msg_prefix: String prefix to be printed with progress messages.

     Notes:
       -This routine will slow as the number of bins (N) increases.
        Averaging will significantly lengthen the required time.

     $LastChangedBy: egrimes $
     $LastChangedDate: 2018-04-12 13:51:19 -0700 (Thu, 12 Apr 2018) $
     $LastChangedRevision: 25039 $
     $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_geo.pro $

(See general/science/spd_slice2d/core/spd_slice2d_geo.pro)

## SPD_SLICE2D_GET_DATA

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_get_data

    Purpose:
      Helper function for spd_slice2d.pro
      Returns an array of averaged data along with the corresponding
      bin centers and widths in spherical coordinates. This routine
      will apply energy range constraints and count thresholds.

    Input:
      dist_array: Array of 3d data structures
      trange: Two element time range
      erange: Two element array specifying min/max energies to be used
      energy: flag to get energy instead of velocity bins for radial distances

    Output:
      data: N element array containing averaged particle data
      rad: N element array of bin centers along r (eV or km/s)
      phi: N element array of bin centers along phi
      theta: N element array of bin centers along theta
      dr: N element array of bin widths along r (eV or km/s)
      dp: N element array of bin widths along phi
      dt: N element array of bin widths along theta

    Notes:

    $LastChangedBy: egrimes $
    $LastChangedDate: 2018-03-26 12:33:55 -0700 (Mon, 26 Mar 2018) $
    $LastChangedRevision: 24954 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_get_data.pro $

(See general/science/spd_slice2d/core/spd_slice2d_get_data.pro)

## SPD_SLICE2D_GET_EBOUNDS

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_get_ebounds

    Purpose:
      Returns an array of gapless energy boundaries.  The number of
      elements returned will always be N+1 for N energy levels.

    Input:
      dist: 3D particle data structure

    Output:
      return value: Array of energy bin boundaries (# energy bins + 1)

    Notes:
      Energy levels may be ordered differently between instruments

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-10-02 20:01:21 -0700 (Fri, 02 Oct 2015) $
    $LastChangedRevision: 18995 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_get_ebounds.pro $

(See general/science/spd_slice2d/core/spd_slice2d_get_ebounds.pro)

## SPD_SLICE2D_GET_SPHERE

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_get_sphere

    Purpose:
      Helper function for spd_slice2d_getdata
      Calculates the center and width of all bins in spherical coordinates.

    Input:
      dist: 3D data structure
      energy: flag to return energy as radial componenet instead of velocity

    Output:
      data: N element array containing interpolated particle data
      rad: N element array of bin centers along r (eV or km/s)
      phi: N element array of bin centers along phi
      theta: N element array of bin centers along theta
      dr: N element array of bin widths along r (eV or km/s)
      dp: N element array of bin widths along phi
      dt: N element array of bin widths along theta

    Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-10-02 20:01:21 -0700 (Fri, 02 Oct 2015) $
    $LastChangedRevision: 18995 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_get_sphere.pro $

(See general/science/spd_slice2d/core/spd_slice2d_get_sphere.pro)

## SPD_SLICE2D_INTRANGE

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_intrange

    Purpose:
      Helper function for spd_slice2d.
      Retrieves the indices of all samples in the specified
      time range from a particle distribution pointer.

    Input:
      ds: (pointer) Single particle distribution pointer.
      trange: (double) Two element array specifying the slice's time range.

    Output:
      return value: indices of all sample within trange.
      n: number of samples

    Notes:
      Uses the center of each sample's time window.

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_intrange.pro $

(See general/science/spd_slice2d/core/spd_slice2d_intrange.pro)

## SPD_SLICE2D_NEAREST

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_nearest

    Purpose:
      Helper function for spd_slice2d.
      Get a time range that encompasses a specified number of
      samples closest to a specified time range.

    Input:
      ds: (pointer) Particle distribution pointer array.
      time: (double) Time near which to search
      samples: (int/long) Number of samples to use

    Output:
      return value: (double) two element time range

    Notes:
      Uses the center of each sample's time window to determine distance.

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-12-02 19:04:33 -0800 (Wed, 02 Dec 2015) $
    $LastChangedRevision: 19516 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_nearest.pro $

(See general/science/spd_slice2d/core/spd_slice2d_nearest.pro)

## SPD_SLICE2D_ORIENTSLICE

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_orientslice

    Purpose:
      Helper function for spd_slice2d.
      Performs transformation into user specified coordinates.
      This transformation is applied after the CUSTOM_ROTATION
      and ROTATION transformation have been performed.

    Input:
      slice_z: (float) 3 vector specifying the slice's normal
      slice_x: (float) 3 vector to be projected into the slice plane
      vectors: (float) N x 3 array of velocity vectors
      bfield: (float) magnetic field 3-vector
      vbulk: (float) bulk velocity 3-vector
      sunvec: (float) spacecraft-sun direction 3-vector

    Output:
      If 2d or 3d interpolation are being used then this will transform
      the velocity vectors and support vectors into the target coordinate system.
      The transformation matrix will be passed out via the MATRIX keyword.

    Input/Output (transformed if present):
      vectors:  array of particle 3 vectors
      bfield: b field vector
      vbulk: bulk velocity vector
      sunvec: sun position vector

    Notes:

    $LastChangedBy: jimm $
    $LastChangedDate: 2020-05-04 13:37:27 -0700 (Mon, 04 May 2020) $
    $LastChangedRevision: 28663 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_orientslice.pro $

(See general/science/spd_slice2d/core/spd_slice2d_orientslice.pro)

## SPD_SLICE2D_RLOG

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_rlog

    Purpose:
      Apply radial log scaling to aggregated velocity/energy vectors.

    Input:
      r: N element array of radii
      dr: N element array of radial bin withds (full width)
      displacement: scalar denoting slice's offset of the origin along the normal

    Output:
      None, modifies input variables by tranforming into log space and normalizing
      along the range of the data.

    Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_rlog.pro $

(See general/science/spd_slice2d/core/spd_slice2d_rlog.pro)

## SPD_SLICE2D_ROTATE

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_rotate

    Purpose:
      Helper function for spd_slice2d.
      Performs transformation to coordinates specified by ROTATION option.
      This is done after the CUSTOM_ROTATION is applied.

    Input:
      vectors: (float) N x 3 array of velocity vectors
      bfield: (float) magnetic field 3-vector
      vbulk: (float) bulk velocity 3-vector
      sunvec: (float) spacecraft-sun direction 3-vector

    Output:
      If 2d or 3d interpolation are being used then this will transform
      the velocity vectors and support vectors into the target coordinate system.
      The transformation matrix will be passed out via the MATRIX keyword.

    Notes:
      This assumes the transformation does not change substantially over the
      time range of the slice.

    $LastChangedBy: egrimes $
    $LastChangedDate: 2022-03-08 13:25:16 -0800 (Tue, 08 Mar 2022) $
    $LastChangedRevision: 30661 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_rotate.pro $

(See general/science/spd_slice2d/core/spd_slice2d_rotate.pro)

## SPD_SLICE2D_S2C

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_s2c

    Purpose:
      Helper function for spd_slice2d_getxyz
      Converts spherical coordinates to cartesian

    Input:
      r: N element array of radial values (can be any dimensions)
      theta: N element array of theta values ( " )
      phi: N element array of phi values ( " )

    Output:
      vec: Nx3 array of cartesian values in x,y,z order

    Notes:
      could probably just use sphere_to_cart?

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_s2c.pro $

(See general/science/spd_slice2d/core/spd_slice2d_s2c.pro)

## SPD_SLICE2D_SMOOTH

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_smooth

    Purpose:
      Helper function for spd_slice2d.
      Smooths the output data by applying a gaussian blur.

    Input:
      slice: (float) N x N array containing the slice data
      width: (int) width of smoothing window in points in both x and y

    Output:
      None, modifies slice array.

    Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-08 18:47:45 -0700 (Tue, 08 Sep 2015) $
    $LastChangedRevision: 18734 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_smooth.pro $

(See general/science/spd_slice2d/core/spd_slice2d_smooth.pro)

## SPD_SLICE2D_SUBTRACT

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_subtract

    Purpose:
      Shift velocities by specified vector

    Calling Sequence:
      spd_slice2d_subtract, vectors=vectors, velocity=velocity, fail=fail

    Input:
      vectors:  Nx3 array of vectors in km/s
      velocity:  3-vector to shift by in km/s

    Output:
      fail:  contains error message if error occurs

    Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2015-09-18 18:17:56 -0700 (Fri, 18 Sep 2015) $
    $LastChangedRevision: 18847 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_subtract.pro $

(See general/science/spd_slice2d/core/spd_slice2d_subtract.pro)

## SPD_SLICE2D_TRANSLATE

[Previous Routine] [Next Routine] [List of Routines]

    Procedure:
      spd_slice2d_translate

    Purpose:
      Shift xyz by specified vector

    Calling Sequence:
      spd_slice2d_translate, vectors=vectors, translate=translate, fail=fail

    Input:
      vectors:  Nx3 array
      translate:  3-vector to shift by
    Keyword:
      truncate: cut the data of the exeded domain

    Output:
      fail:  contains error message if error occurs

    Notes:

    $LastChangedBy: adrozdov $
    $LastChangedDate: 2018-05-21 12:46:11 -0700 (Mon, 21 May 2018) $
    $LastChangedRevision: 25240 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_slice2d_translate.pro $

(See general/science/spd_slice2d/core/spd_slice2d_translate.pro)

## SPD_TPLOT_AVERAGE

[Previous Routine] [List of Routines]

     Name:
       spd_tplot_average.pro

     Purpose:
       Returns the average value of a tplot variable over a specified time range.

     Calling Sequence:
       result = spd_tplot_average( tplot_var, trange [,interpolate=interpolate] )

     Input:
       tplot_var: String containing the name of valid tplot variable
       trange: String or double specifying the time range
       interpolate: Flag to attempt interpolation from data outside the specifed
                    range if none is found within.  At least 20 min or half the
                    specified range will be checked past both time limits.

     Output:
       return value: averate of tplot variable's y component or NaN if unsuccessful

     Example Usage:
       trange = '2008-4-12/' + ['01:00','02:00']
       bfield_ave = spd_tplot_average('bfield_data', trange)

     Notes:

    $LastChangedBy: aaflores $
    $LastChangedDate: 2016-05-13 17:46:11 -0700 (Fri, 13 May 2016) $
    $LastChangedRevision: 21085 $
    $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/general/science/spd_slice2d/core/spd_tplot_average.pro $

(See general/science/spd_slice2d/core/spd_tplot_average.pro)