Batchalign
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Purpose
Convert data columns based on matching a reference column to a target vector.
Synopsis
- aligned = batchalign(data,ref_column,target,options)
Description
Stretch or contract data columns based on a target using given method. Savgol options can be used to exaggerate transitions in data prior to cow.
Inputs
- data = (nsample, nvar) dataset or double array containing data columns to align.
- ref_column = scalar indicating the column # of data that we are going to match OR ref_vector which is a vector to use in match.
- target = (nsample, 1) vector or dataset to which we are trying to match the ref_column or ref_vector.
Outputs
- aligned: dataset or double array (depending on input data type) containing the aligned data. If it is a dataset of different number of rows from input then the class, axisscale and labels are set according to the closest row in input dataset.
Options
options = a structure array with the following fields:
- method: [ 'linear' | {'cow'} | 'padwithnan' ] Alignment method.
- 'linear' means the data columns are extented/contracted using linear interpolation to have the same number of data points as the target vector.
- 'cow' applies Correlation Optimized Warping to match the reference column to the target vector, then apply the same transformation to the other columns.
- 'padwithnan' uses NaN values to extend columns, or truncates columns, to have the same number of data points as the target vector.
- savgolwidth: Number of points in savgol filter.
- savgolorder: Order of savgol polynomial.
- savgolderiv: [0,1,2...] Order of derivative to take of target and ref_column before doing alignment (default = 0).
Cow only options.
- cow: structure with the following fields:
- cow.segments : Segment length.
- cow.slack: max range of warping. 'slack' value must be less than or equal to segments minus 4.
- cow.plots: Governs plotting with COW (0 = no plots).
- cow.correlationpower: correlation power.
- cow.forceequalsegs: Force equal segment lengths in "xt" and "xP".
- cow.fixmaxcorrection: Fix maximum correction.