LTPDA Toolbox™

contents

Version 2.4 LTPDA Toolbox Software

This table summarizes what's new in Version 2.4:

• Introduction
• New features and major changes
• Extension modules
• Saving and loading AOs
• Preferences
• Logical AOs
• Plotting AOs
• Error propagation
• Matrix constructors
• New class methods
• Removed methods
• Multiplying matrices of AOs
• Method outputs
• Changes to evaluating smodel and pest object
• Smodel class has new properties
• Built-in model format
• SSM class user-interface
• Detrending
• Other Minor Changes of Note
• MANTIS Issues Resolved

Introduction

This version of LTPDA is 2.4. This document lists the changes since V2.3.1.

This version requires MATLAB 2010a or above

The main focus of this release has been on code optimisation to improve execution speed and to aid in maintainability. There have also been some fairly major changes to the toolbox, so keep reading to find out what they are! In addition, a significant number of bugs and change requests have been addressed.

New features and major changes

Extension modules

LTPDA now supports 3rd party extension modules. See the LTPDA user manual for details how to build and install extension modules.

Note: this is now the supported way to add your own-built in models to LTPDA. The old scheme of adding directories in the LTPDA preferences is no longer supported and has been removed. Users with their own built-in models should build an extension module and move the models in to the extension module. The user manual explains where to put them.

Saving and loading AOs

• ao/saveIf the user doesn't specify the filename then save saves the object(s) as a MAT file using the variable name in the current folder
• The AO constructor for loading data from ASCII files now makes fewer assumptions about the content of the file. Instead the user is expected to pass more information in the plist. The only assumption we make is that the data files contains at least one column of data. As such, the call
  a = ao('mydata.txt')
  will result in a cdata AO containing the all columns of data in the file stored as a matrix.
• When constructing AOs from files, all file extensions other than 'xml' and 'mat' are treated as if they contain ASCII data.

Preferences

LTPDA preferences has new panel for configuring the default look of plots

Logical AOs

AOs now accept logical values for construction and we have some new logical logical operators (see below).

Plotting AOs

ao/iplot now has a new plist key for overriding the default legend font size 'LegendFontSize'. You can also include object descriptions in the legend by setting the corresponding preference is set in LTPDAprefs.

ao/iplot The use of the 'xmaths', 'ymaths', and 'zmaths' parameters is now deprecated and will be removed in a future release.

Error propagation

More AO methods now propagate errors: ao/scale, ao/power, ao/mtimes, ao/mrdivide.

Matrix constructors

We have some new constructors for the matrix class:

matrix(plist('values', ..., 'names', ..., 'yunits', ...))
matrix(doubleArray)
matrix(doubleArray, cellArray)

New Class Methods

• smodel/hessian computes the hessian matrix for smodels
• ao/intersect forms the intersection of two AOs
• new logical binary operators for AO class: ao/and, ao/or
• ao/bicohere computes the bicoherence of two input time-series. The result is a complex frequency-frequency-complex coherence map.
• ao/average is a method to average AOs point-by-point. For each point, an average is taken over all the input objects.
• New AO factory constructors:
  1. ao.randn(nsecs, fs) - produces a time-series of random numbers
  2. ao.randn(nsamples) - produces a cdata AO of random numbers
  3. ao.sinewave(nsecs, fs, f0, phi) - produces a time-series of a sine-wave
  4. [o1, o2, ...] = ao.load(filename) - load multiple objects from a file. You need to know how many objects are in the file so that you can specify the correct number of output objects.
• ltpda_uoh/requirements lists the required extensions for rebuilding an object.
• ao/zunits returns the zunits of an xzydata AO
• ao/setZunits sets the units of the z-data for an xyzdata AO
• We added a new AO constructor from a parameter contained in a plist. Suppose we have a plist containing a key 'a', then we can make a cdata AO with the value of 'a'. Other properties are also used in constructing the AO (at the moment only properties 'unit' and 'units' are supported). All properties are added to the procinfo.
  e.g. a = ao(plist('parameter', pl, 'key', 'a'))

Removed methods

Some LTP-specific methods have been removed and moved in to extension modules.

The following were all moved to the LPF_DA_Module extension module:

• ao/ltp_ifo2ac
• ao/smallvec_coef
• ao/smallvector_lincom
• ao/smallvectorfit
• ao/mdc1_ifo2acc_inloop
• ao/mdc1_ifo2cont_utn
• ao/mdc1_cont2act_utn
• ao/mdc1_ifo2control
• ao/mdc1_ifo2acc_fd_utn
• ao/mdc1_x2acc
• ao/mdc1_ifo2acc_fd
• pest/LTPimperf2physParams

Other methods removed which were deprecated in previous releases:

• ao/pwelch - use ao/psd instead
• ao/curvefit - use ao/xfit or ao/tdfit instead
• ao/straightLineFit - use ao/linfit instead
• ao/timedomainfit - use ao/lscov instead
• pest/toAO - use pest/find instead
• ao/ltpda_fitChiSquare
• ao/hist_gauss use ao/hist instead

Multiplying matrices of AOs

Given two matrices of AOs, the inner multiplication operator has changed from a matrix multiplication to an element multiplication.

M1 = [a1 a2; a3 a4]; % a# is an AO
M2 = [b1 b2; b3 b4]; % b# is an AO
M = M1*M2

then M(1) = a1.*b1 + a2.*b3

Method outputs

The output of some methods are now matrix objects and no longer vectors of AOs to make rebuilding work:

• ssm/simulate
• ssm/CPSD
• ssm/PSD
• ssm/bode
• ssm/kalman
• ssm/resp

ao/rotate no longer supports the multiple output function call.

To retrieve the AOs from inside the matrix object in a 'history safe' way, use matrix/getObjectAtIndex.

matrix/det no longer returns a matrix object, but instead an object of the same class as the inner objects.

Smodel class has new properties

The xvals field is now always a cell-array of vectors

The properties aliasNames and aliasValues can be used to defines variable aliases which are then used in the model expression.

The trans field usage is depracted in favour of setting an alias.

Changes to evaluating smodel and pest object

The smodel/double method has been harmonized with Matlab double: the values for the independent variables x must now be vectors of double, and they must be set before the call to the method, that now has no parameters.

The smodel/eval method has been changed to build the output AO is built from the smodel, based on these parameters:

• 'output type' to choose the output data type
• 'output x', to choose the X values for the output data ao. In case of a double vector, the result is a cdata AO. In case of an ao, the output is a copy of this object but the ''y'' field is calculated from the model.

As a consequence, the pest/eval method has been modified. If the user input the independent variable values XDATA within aos, their 'y' field will be used if not otherwise specified. This is different from previous versions of the Toolbox. Furthermore, if the user input the independent data XDATA within aos, the output data type will be of the same type.

Built-in model format

The format of built-in models was completely written to allow a more flexible versioning of models. You can build new-style built-in models using the utility utils.models.makeBuiltInModel(). See the documentation for more details.

ssm class user-interface

The user interface of some ssm class methods was simplified and changed. As such, some old usages may no longer work. Please consult the relevant method help if you encounter any problems.

Detrending

Default detrending order in ao/detrend was changed from 0 to 1 to match the corresponding MATLAB detrend behaviour.

Other Minor Changes of Note

• The verbose level for many output messages was increased to make LTPDA a bit quieter.
• User objects now have an empty default name.
• ao/search now properly tracks history
• constructing AOs from data files ('from ASCII' constructor) works with arbitrary delimiters now. The delimiter can be set in the plist.
• ao/fft and ao/ifft support a scaling option ('scale' plist key) which scales the output by the sampling rate if the AO is a time-series.
• ssm class speed improvements for bode and simulate
• ao/select now returns an AO with the x-field filled, even if the result is evenly sampled. The idea here is that selecting samples from a vector (especially a time-series) is not well defined in terms of the resulting sample rate. So we leave the x data alone and let the user decide what to do next.

MANTIS Issues Resolved

Version 2.5 LTPDA Toolbox Software

Version 2.3.1 LTPDA Toolbox Software

©LTP Team