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Procedure: fac_matrix_make Purpose: generates a field aligned coordinate transformation matrix from an input B vector array(and sometimes a position vector array) then stores it in a tplot variable Arguments: mag_var_name=the name of the tplot variable storing the magnetic field vectors to be used in transformation matrix generation pos_var_name(optional)=the name of the tplot variable storing the position vectors to be used in transformation matrix generation newname(optional)=the name of the tplot variable in which to store the output error(optional) = named variable that holds the error state of the computation 1 = success 0 = failure other_dim(optional) = the second axis for the field aligned coordinate system. ************For all transformations Z = B************ valid second coord(other_dim) options: 'Xgse', translates from gse or gsm into FAC Definition(works on GSE or GSM): X Axis = on plane defined by Xgse - Z Second coordinate definition: Y = Z x X_gse Third coordinate, X completes orthogonal RHS (right hand system) triad: XYZ 'Rgeo',translate from geo into FAC using radial posision vector R_pos is radial position vector, radialy inwards. Second coordinate definition: Y = Z x Rpos Third coordinate, X completes orthogonal RHS XYZ. 'Ygeo', translate from geo into FAC using azimuthal position vector Y_pos is the azimuthal position vector, positive Westward Second coordinate definition: Y = Z x Y_pos Third coordinate, X completes orthogonal RHS XYZ Example: fac_matrix_make,'tha_fgs','Xgeo',pos_var_name='tha_pos',out_var_name='tha_fgs_fac_mat' Notes:--> I'm a little sparse on comments here, but I think the code should be self documenting
(See ssl_general/cotrans_var/fac_matrix_make.pro)
Procedure: minvar.pro This program computes the principal variance directions and variances of a vector quantity (can be 2D or 3D). This routine is a simple version designed to be used by a tplot wrapper with the contrans_var library Input: Vxyz, an (ndim,npoints) array of data Output: eigenVijk, an (ndim,ndim) array containing the principal axes vectors Maximum variance direction eigenvector, Vi=eigenVijk(*,0) Intermediate variance direction, Vj=eigenVijk(*,1) (descending order) Vrot: if set to a name, that name becomes an array of (ndim,npoints) containing the rotated data in the new coordinate system, ijk. Vi(maximum direction)=Vrot(0,*) Vj(intermediate direction)=Vrot(1,*) Vk(minimum variance direction)=Vrot(2,*) lambdas2=if set to a name returns the eigenvalues of the computation Written by: Vassilis Angelopoulos $LastChangedBy: pcruce $ $LastChangedDate: 2007-08-13 17:37:26 -0700 (Mon, 13 Aug 2007) $ $LastChangedRevision: 1401 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans_var/minvar.pro $
(See ssl_general/cotrans_var/minvar.pro)
Procedure: minvar_matrix_make Purpose: wrapper for minvar.pro, uses tplot variables, can generate multiple transformation matrices using sliding average Arguments: in_var_name: the name of the tplot variable holding the input data, can be any sort of timeseries 3-d data tstart(optional): the start time of the data you'd like to consider for generating the transformation matrix(defaults to minimum time of in_var timeseries) tstop(optional): the stop time of the data you'd like to consider for generating the transformation matrix(defaults to maximum time of in_var timeseries) twindow(optional): the size of the window(in seconds) you'd like to consider when using a moving boxcar average to generate multiple transformations. (defaults to the entire time series) tslide(optional): the number of seconds the boxcar should slide forward after each average.(defaults to twindow/2xo) newname(optional): the name of the tplot variable in which to store the transformation matrix(matrices) (defaults to in_var_name+'_mva_mat' evname(optional): the name of the tplot variable in which to store the eigenvalues of the mva matrix(matrices) (defaults to nowhere, ie if unset doesn't store them error(optional): named variable that holds the error state of the computation, 1=success 0 = failure $LastChangedBy: pcruce $ $LastChangedDate: 2007-08-15 09:49:12 -0700 (Wed, 15 Aug 2007) $ $LastChangedRevision: 1420 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans_var/minvar_matrix_make.pro $
(See ssl_general/cotrans_var/minvar_matrix_make.pro)
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_var/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_var/tdotp.pro)
Procedure: thm_crib_fac Purpose: A crib on showing how to transform into field aligned coordinates Notes: $LastChangedBy: pcruce $ $LastChangedDate: 2007-08-14 13:40:52 -0700 (Tue, 14 Aug 2007) $ $LastChangedRevision: 1410 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans_var/thm_crib_fac.pro $
(See ssl_general/cotrans_var/thm_crib_fac.pro)
Procedure: thm_crib_mva Purpose: A crib on showing how to transform into minimum variance analysis coordinates Notes: $LastChangedBy: pcruce $ $LastChangedDate: 2007-08-15 11:24:29 -0700 (Wed, 15 Aug 2007) $ $LastChangedRevision: 1423 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans_var/thm_crib_mva.pro $
(See ssl_general/cotrans_var/thm_crib_mva.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 uses x component for x abcissa values uz_tvar = tplot variable that V will be fit to uses x component for u abcissa values newname = output variable name(optional) defaults to xv_tvar+'_interp' /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 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: 2007-08-14 16:33:34 -0700 (Tue, 14 Aug 2007) $ $LastChangedRevision: 1412 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans_var/tinterpol_mxn.pro $
(See ssl_general/cotrans_var/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: pcruce $ $LastChangedDate: 2007-08-10 15:40:38 -0700 (Fri, 10 Aug 2007) $ $LastChangedRevision: 1378 $ $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/ssl_general/trunk/cotrans_var/tnormalize.pro $
(See ssl_general/cotrans_var/tnormalize.pro)
Procedure: tvector_rotate Purpose: rotates a set of vectors by a set of coordinate transformation matrices inputs and outputs are tplot variables Arguments: mat_var_in: the name of the tplot variable storing input matrices vec_var_in: the name of the tplot variable storing input vectors newname(optional): the name of the output variable, defaults to mat_var_in + '_times_' + vec_var_in 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:
(See ssl_general/cotrans_var/tvector_rotate.pro)