This page was created by the IDL library routine
mk_html_help2.
Last modified: Wed Jun 24 12:41:17 2009.
PROCEDURE: TCROSSP Purpose: Vectorized routine to calculate the cross product of two tplot variables containing arrays of 3d vectors and storing the result in a tplot variable Arguments: v1: The name of the tplot variable storing the first vector in the cross product v2: The name of the tplot variable storing the second vector in the cross product newname(optional): the name of the output tplot variable error(optional): named variable in which to return error state of the computation. 1 = success 0 = failure NOTES:
(See ssl_general/cotrans/special/tcrossp.pro)
PROCEDURE: TDOTP Purpose: Vectorized routine to calculate the dot product of two tplot variables containing arrays of vectors and storing the results in a tplot variable Arguments: v1: The name of the tplot variable storing the first vector in the dot product v2: The name of the tplot variable storing the second vector in the dot product newname(optional): the name of the output tplot variable error(optional): named variable in which to return the error state of the computation. 1 = success 0 = failure NOTES:
(See ssl_general/cotrans/special/tdotp.pro)
Function: tinterpol_mxn
Purpose: Generalized interpolates across a series of vectors(since
interpol only works on 1-d vectors) This function works on any
n-dimensional vectors. Basically, this is an element by element
interpolation across M
- i. works on tplot variables
- ii. allows no extrapolation beyond valid data with
/no_extrapolate keyword"
Arguments:
xv_tvar = tplot variable to be interpolated, the y component
can have any dimesions, can use globbing to interpolate
many values at once
uses x component for x abcissa values
uz_tvar = tplot variable that V will be fit to
uses x component for u abcissa values. Can also
pass in an array of time values rather than a tplot
variable.
newname = output variable name(optional) defaults to
xv_tvar+'_interp'
suffix = a suffix other than interp you can use,
particularily useful when using globbing
overwrite=set this variable if you just want
the original variable overwritten instead of using
newname or suffix
Use only newname or suffix or overwrite. If you combine
them the naming behavior may be erratic
/LINEAR = pass this argument to specify linear
interpolation(this is the default behavior)
/QUADRATIC = pass this argument to specify quadratic
interpolation
/SPLINE = pass this argument to specify spline
interpolation
/NO_EXTRAPOLATE = pass this argument to prevent
extrapolation of data values in V passed it's start and
end points
/NAN_EXTRAPOLATE = pass this argument to extrapolate past
the endpoints using NaNs as a fill value
ERROR(optional): named variable in which to return the error state
of the computation. 1 = success 0 = failure
CALLING SEQUENCE;
tinterpol_mxn,'tplot_var1','tplot_var2',out_var='tplot_var_out'
tinterpol_mxn,'tplot_var1','tplot_var2',/NO_EXTRAPOLATE
tinterpol_mxn,'tplot_var1','tplot_var2',/SPLINE
Output: an N by D1 by D2 by ... array stored in an output tplot variabel
Notes:
Uses a for loop over D1*D2*..., but I'm operating under the assumption that
D1*D2... << M (D1 * D2 *... is waaaay less than M)
It uses a little bit of modular arithmatic so this function is
generalized to any array dimensionality(IDL limits at 8)
Examples:
if the input is an array of 3-d vectors(say 1,1,1 and 2,2,2) and we
want 3 vectors out the output is 1,1,1 1.5 1.5 1.5 2,2,2
if the input is an array of 3x3 matrices(say all ones and all twos)
and we want three matrices then output is all 1s all 1.5s all 2s
$LastChangedBy: pcruce $
$LastChangedDate: 2008-12-05 09:42:42 -0800 (Fri, 05 Dec 2008) $
$LastChangedRevision: 4106 $
$URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/tags/tdas_5_1/cotrans/special/tinterpol_mxn.pro $
(See ssl_general/cotrans/special/tinterpol_mxn.pro)
PROCEDURE: TNORMALIZE Purpose: Vectorized routine to normalize all the vectors stored in a tplot variable Arguments: v: The name of the tplot variable storing the vectors to be normalized newname(optional): The name of the output tplot variable. Defaults to v+'_normalized' error(optional): Named variable in which to return the error state of the computation, 1 = success, 0 = failure NOTES: $LastChangedBy: bckerr $ $LastChangedDate: 2008-07-31 16:52:00 -0700 (Thu, 31 Jul 2008) $ $LastChangedRevision: 3322 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/tags/tdas_5_1/cotrans/special/tnormalize.pro $
(See ssl_general/cotrans/special/tnormalize.pro)
Procedure: tvector_rotate
Purpose: rotates a set of vectors by a set of coordinate
transformation matrices inputs and outputs are tplot
variables. This is designed mainly for use with
fac_matrix_make.pro and minvar_matrix_make, but can be used
for more general purposes
Warning:
The transformation matrices generated by
fac_matrix_make,thm_fac_matrix_make, and minvar_matrix_make are
defined relative to a specific coordinate system. This means that if
you use vectors in one coordinate system to generate the rotation
matrices they will only correctly transform data from that coordinate
system into the functional coordinate system. For example if you use
magnetic field data in gsm to generate Rgeo transformation matrices
using fac_matrix_make then the vectors being provided to tvector
rotate to be transformed by those matrices should only be in gsm coordinates.
Arguments:
mat_var_in: the name of the tplot variable storing input matrices
The y component of the tplot variable's data struct should be
an Mx3x3 array, storing a list of transformation matrices.
vec_var_in: the name of the tplot variable storing input
vectors. You can use globbing to rotate several tplot variables
storing vectors with a single matrix. The y component of the tplot variable's
data struct should be an Nx3 array.
newname(optional): the name of the output variable, defaults to
vec_var_in + '_rot'
If you use type globbing in the vector variable
This option will be disabled
error(optional): named variable in which to return the error state
of the computation. 1 = success 0 = failure
CALLING SEQUENCE:
tvector_rotate,'matrix_var','vector_var',newname = 'out_var',error=error
tvector_rotate,'matrix_var','vector_var'
Notes:
mat_var_in should store rotation matrices. (ie the columns of any
matrix in mat_var_in should form an orthonormal basis)
If M!=N M must be >= 2 (where M,N refer to the dimensions of the
input variables.
Also If the x components of mat_var_in and vec_var_in data structs
do not match then. The matrices will be interpolated to match the
cadence of the vector data. Interpolation is done by turning the
matrices into quaternions and performing spherical linear
interpolation. As noted above this interpolation behavior will
not be predictable if the matrices do anything other than rotate.
The user should note that if the timestamps of mat_var_in are not
monotonic(ascending or identical) or if the timestamps vec_var_in are not strictly
monotonic(always ascending) the program will not work correctly. It is the user's
responsibility to remove duplicate or non sequential timestamps from the data
PROGRAMMERS: you might want to consider adding a check to
verify that input matrices are actually rotation matrices
this would just verify that M dot transpose(M) = Identity matrix
SEE ALSO: mva_matrix_make.pro, fac_matrix_make.pro
$LastChangedBy: pcruce $
$LastChangedDate: 2009-03-30 14:17:08 -0700 (Mon, 30 Mar 2009) $
$LastChangedRevision: 5454 $
$URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/tags/tdas_5_1/cotrans/special/tvector_rotate.pro $
(See ssl_general/cotrans/special/tvector_rotate.pro)