User Manual

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There are many different Matlab commands within Libisis. These include basic commands, such as taking the exponential of a dataset, through to integration and plotting commands. The following is an online user manual for the matlab interface of the Libisis software.


There are many different object types within Libisis used to store experimental data. Once an object is created, functions exist to manipulate the data contained within. The most common objects for plotting and data manipulation are IXTdataset_1d, IXTdataset_2d and IXTdataset_3d objects. IXTrunfile objects contain all raw data from a run.

IXTdataset_1d objects store signal and error information against one dimension (the x axis). Label and titling information is also stored. IXTdataset_2d objects also contain a second dimension (the y axis). As would be expected IXTdataset_3d objects contain yet another (z) dimension. IXTpolygons contains a list of shapes with signal data that can be plotted. All relevant data pertaining to a run can be stored in an IXTrunfile object. The object can be thought of as an array of IXTdataset_2d objects with a lot of additional information. IXTdataset_1d, IXTdataset_2d and IXTrunfile have fully implemented and similar functions, IXTdataset_3d and IXTpolygons are a special case and do not have many of the data manipulation functions as of yet.

Data is read into these objects (using methods described below) and can then be manipulated using many different tools and functions described in this documentation.

General Behaviour

Most functions share a general behaviour outlined here

Data Manipulation Functions

Input and Output Functions

Below are just a few of the possible read and write functions, other formats can also be used.

  • Homer - Information about using Homer to import data into Libisis

Binary Operators

Binary operators such as +, -, *, etc. are used to perform arithmetic operations between datasets and/or numbers

Elementary Functions

Elementary functions act on each signal element identically

  • log, exp - logarithmic functions

Data Manipulation Functions

Rebin Functions

Three different methods exist for rebinning a function. Rebin will rebin the data into user defined bins. Rebunch will bunch together a user defined number of bins. Regroup rebins data using a minimum binwidth given by the user but insures that the new bins are coincident with the existing bins.

High Level Functions

  • smooth - Smooths out signal data to avoid small, sharp deviations
  • unspike - Removes any large spikes from the data
  • fit - Fitting data to known functions and giving curves of best fit
  • func_eval - Evaluate a function at the given x and y data points

Special Functions

Special functions are used to transform data between different types.


Using Default Properties and Name Tags

Default properties and name tags are an integral part of Libisis graphics. They allow greater control of plots and it is particularly important to know about them when building applications on top of the Libisis structure. Names and tags can be used to easily identify and set properties for plots.

Plot Commands

  • ds, da, mp - Two dimensional plotting commands
  • sm - Sliceomatic (three dimensional) plotting

Pre-Emptive Formatting

Retrospective Formatting

  • lx, ly, lz - Changes the limits of the axes
  • aspect - changes the aspect ratio
  • dxy,dxyz,dxyc - returns the co-ordinates of a clicked point on a plot, and/or marks the point with a label

Other Commands

  • rename - rename a plot but keep default properties
  • undop - undo the last plot
  • alias - make an alias for a function

User Reference

Information for reference purposes, such as valid linestyles, marker styles etc.


A general tutorial. This is mainly from the graphics viewpoint but should provide a good overview of how to do things.