Scaffolding MATLAB and octave software comprehension through visualization

Multiple view interactive environments (MVIEs) provide visual resources to support the comprehension of a specific domain dataset. For any domain, different views can be selected and configured in a real time fashion to be better adjusted to the user needs. This paper focuses on the use of a MVIE called OctMiner to support the comprehension of MATLAB and GNU/Octave programs. The authors conducted a case study to characterize the use of OctMiner in the context of comprehension activities. Results provide preliminary evidence of the effectiveness of OctMiner to support the comprehension of programs written in MATLAB and Octave.info:eu-repo/semantics/acceptedVersio

A multiple view interactive environment to support MATLAB and GNU/Octave program comprehension

Program comprehension plays an important role in Software Engineering. In fact, many of the software lifecycle activities depend on program comprehension. Despite the importance of MATLAB and Octave programing languages in the Engineering and Statistical communities, little attention has been paid to the conception, implementation and characterization of tools and techniques for the comprehension of programs written in these languages. Considering this scenario, this paper presents a Multiple View Interactive Environment (MVIE) called OctMiner that supports the comprehension of programs developed in the aforementioned languages. OctMiner provides a set of coordinated visual metaphors that can be adjusted in accordance with the comprehension goals. An example is presented to illustrate the main functionalities of OctMiner in a real scenario of program comprehension.info:eu-repo/semantics/acceptedVersio

On the use of a multiple view interactive environment for MATLAB and octave program comprehension

WOS:000364988500049 (Nº de Acesso Web of Science)MATLAB or GNU/Octave programs can become very large and complex and therefore difficult to understand and maintain. The objective of this paper is presenting an approach to mitigate this problem, based upon a multiple view interactive environment (MVIE) called OctMiner. The latter provides visual resources to support program comprehension, namely the selection and configuration of several views to meet developers’ needs. For validation purposes, the authors conducted two case studies to characterize the use of OctMiner in the context of software comprehension activities. The results provided initial evidences of its effectiveness to support the comprehension of programs written in the aforementioned languages

SCTBEM: A scaled coordinate transformation boundary element method with 99-line MATLAB code

This paper introduces the Scaled Coordinate Transformation Boundary Element Method (SCTBEM), a novel boundary-type method for solving 3D potential problems. To address the challenges of applying the Boundary Element Method (BEM) to complex problems, it is common practice to use the fundamental solution corresponding to the partial governing equation operator to establish the integral equation. However, this approach introduces domain integral, which may jeopardize the dimensionality reduction advantages of BEM. To preserve the benefits of dimensionality reduction, this paper proposes a novel domain integral transformation method known as the Scaled Coordinate Transformation (SCT). The SCT is purely a mathematical operation that does not rely on particular solution of operators, which requires only discretization on the structure's surface while remaining analytical in the radial direction. An even better novelty is that the lower-order singularity can be eliminated by coordinate translation technique. To facilitate the wider adoption of BEM, the authors present 99-line MATLAB code. Numerical results confirm that the SCTBEM exhibits high numerical accuracy even when dealing with complex model

A concern visualization approach for improving MATLAB and octave program comprehension

The literature has pointed out the need for focusing efforts to better support comprehension of MATLAB and Octave programs. Despite being largely used in the industry and academia in the engineering domain, programs and routines written in those languages still require efforts to propose approaches and tools for its understanding. Considering the use of crosscutting concerns (CCCs) to support the comprehension of object-oriented programs, there is room of its use in the context of MATLAB and Octave programs. The literature has purpose and examples in this direction. Considering this scenario, we propose the use of visualization enriched with CCCs representation to support the comprehension of such programs. This paper discusses the use of a multiple view interactive environment called OctMiner in the context of two case studies to characterize how collected information relating to crosscutting concerns can foster the comprehension of MATLAB and GNU/Octave programs. As a result of the conducted case studies, we propose strategies based on OctMiner and tailored to support different comprehension activities of programs written in MATLAB and Octave.info:eu-repo/semantics/acceptedVersio

On source space resolution in EEG brain imaging for motor imagery

International audienceBrain source localization accuracy is known to be dependent on the EEG sensor placement over the head surface. In Brain-Computer Interfaces (BCI), according to the paradigm used, Motor Imagery (MI) and Steady-State Visual Evoked Potential (SSVEP) in particular, electrodes are not well distributed over the head, and their number is not standardized as in classical clinical applications. We propose in this paper a method for quantifying the expected quality of source localization with respect of the sensor placement, known as EEG montage. Our method, based on a subspace correlation metric, can be used to assess which brain sources can be distinguished (as they generate sufficiently different potentials on the electrodes), and also to identify regions/volumes in which precise source localization is impossible (i.e. all sources inside those regions could generate similar electrode potentials). In particular, for a MI dedicated montage, we show that source localization is less precise than for standard montages, although the local density of electrodes over the areas of interest is higher

OpenMEEG: opensource software for quasistatic bioelectromagnetics

Background: Interpreting and controlling bioelectromagnetic phenomena require realistic physiological models and accurate numerical solvers. A semi-realistic model often used in practise is the piecewise constant conductivity model, for which only the interfaces have to be meshed. This simplified model makes it possible to use Boundary Element Methods. Unfortunately, most Boundary Element solutions are confronted with accuracy issues when the conductivity ratio between neighboring tissues is high, as for instance the scalp/skull conductivity ratio in electro-encephalography. To overcome this difficulty, we proposed a new method called the symmetric BEM, which is implemented in the OpenMEEG software. The aim of this paper is to presen

A bi-atrial statistical shape model for large-scale in silico studies of human atria: model development and application to ECG simulations

Large-scale electrophysiological simulations to obtain electrocardiograms (ECG) carry the potential to produce extensive datasets for training of machine learning classifiers to, e.g., discriminate between different cardiac pathologies. The adoption of simulations for these purposes is limited due to a lack of ready-to-use models covering atrial anatomical variability. We built a bi-atrial statistical shape model (SSM) of the endocardial wall based on 47 segmented human CT and MRI datasets using Gaussian process morphable models. Generalization, specificity, and compactness metrics were evaluated. The SSM was applied to simulate atrial ECGs in 100 random volumetric instances. The first eigenmode of our SSM reflects a change of the total volume of both atria, the second the asymmetry between left vs. right atrial volume, the third a change in the prominence of the atrial appendages. The SSM is capable of generalizing well to unseen geometries and 95% of the total shape variance is covered by its first 23 eigenvectors. The P waves in the 12-lead ECG of 100 random instances showed a duration of 104ms in accordance with large cohort studies. The novel bi-atrial SSM itself as well as 100 exemplary instances with rule-based augmentation of atrial wall thickness, fiber orientation, inter-atrial bridges and tags for anatomical structures have been made publicly available. The novel, openly available bi-atrial SSM can in future be employed to generate large sets of realistic atrial geometries as a basis for in silico big data approaches