Tracing and Debugging of Lazy Functional Programs - A Comparative Evaluation of Three Systems

In this paper we compare three systems for tracing and debugging Haskell programs: Freja, the Redex Trail System and Hood. We identify the similarities and differences of these systems and we evaluate their usefulness in practice by applying them to a number of small to medium programs in which errors had deliberately been introduced

Multiple-View Tracing for Haskell: a New Hat

Different tracing systems for Haskell give different views of a program at work. In practice, several views are complementary and can productively be used together. Until now each system has generated its own trace, containing only the information needed for its particular view. Here we present the design of a trace that can serve several views. The trace is generated and written to file as the computation proceeds. We have implemented both the generation of the trace and several different viewers

Multi-cultural visualization : how functional programming can enrich visualization (and vice versa)

The past two decades have seen visualization flourish as a research field in its own right, with advances on the computational challenges of faster algorithms, new techniques for datasets too large for in-core processing, and advances in understanding the perceptual and cognitive processes recruited by visualization systems, and through this, how to improve the representation of data. However, progress within visualization has sometimes proceeded in parallel with that in other branches of computer science, and there is a danger that when novel solutions ossify into `accepted practice' the field can easily overlook significant advances elsewhere in the community. In this paper we describe recent advances in the design and implementation of pure functional programming languages that, significantly, contain important insights into questions raised by the recent NIH/NSF report on Visualization Challenges. We argue and demonstrate that modern functional languages combine high-level mathematically-based specifications of visualization techniques, concise implementation of algorithms through fine-grained composition, support for writing correct programs through strong type checking, and a different kind of modularity inherent in the abstractive power of these languages. And to cap it off, we have initial evidence that in some cases functional implementations are faster than their imperative counterparts

The Photodissociation of OCS and HN3: Understanding Dynamics in the First Absorption Band

This dissertation is focused on describing the photodissociation dynamics of both OCS and HN3 in the first UV absorption band. The photodissociation of OCS in the first UV absorption band has continuously been a test case for theoretical models. Experimental measurements using Velocity Map Ion Imaging (VELMI) at 214 nm uncovered previously unseen vibrational excitation of the CO fragment. The photodissociation of OCS is known to result in a j-dependent β parameter. The origin of the j-dependence has been hypothesized to occur via two different mechanisms: a two electronic state model and a non-axial recoil model. This work has confirmed the origin of the j-dependent β originates from two nearby electronic states, the A(21A^1) and B(1^1A”) electronic states, of OCS with opposite symmetry. Using these measurements in addition to experimental data from the literature the fractional contributions of each state excited state is determined. The contribution of the B state (fvB) did not agree well with theory over the first absorption band. Additionally, experimental measurements at 214 nm have indicated an underestimation in the surface hopping trajectories in the photodissociation of OCS, possibly originating from discrepancies in the calculated initial impulse along the bending coordinate or the coupling between the ground X(1^1A′ ) and A(2^1A ′ ). The photodissociation of HN3 in the first UV absorption band near 256 nm, 271 nm, and 285 nm were measured using VELMI. A series of images across the HN rotational distribution were collected at each wavelength. The experimental measurements at 285 nm are in good agreement with previous measurements in the literature. Speed dependent vector correlations were successfully measured using the recently developed 2+1 REMPI equations. The speed dependent vector correlations measured from the HN fragment provided insight into the correlated dynamics of the Nv2 cofragment. The speed dependent vector correlations at 285 nm indicated the low jvN2 originated primarily from the νv5 in plane bend, with increasing dependence on the νv6 torsion with increasing jvN2 . In the future, additional measurements of the Nv2 fragment using a 2+2 REMPI scheme at 283 nm are possible. Ion images of the Nv2 fragment would allow for the direct determination of the Nv2 vector properties providing a way to validate the speed dependent vector correlations measured using the 2+1 HN REMPI scheme at 285 nm. Additional measurements at 256 nm and 271 nm are necessary to determine the accuracy of the vector correlations in the current data. Keywords: Photodissociation, VELMI, vector correlations

Dividing population genetic distance data with the software Partitioning Optimization with Restricted Growth Strings (PORGS): an application for Chinook salmon (Oncorhynchus tshawytscha), Vancouver Island, British Columbia

A new method of finding the optimal group membership and number of groupings to partition population genetic distance data is presented. The software program Partitioning Optimization with Restricted Growth Strings (PORGS), visits all possible set partitions and deems acceptable partitions to be those that reduce mean intracluster distance. The optimal number of groups is determined with the gap statistic which compares PORGS results with a reference distribution. The PORGS method was validated by a simulated data set with a known distribution. For efficiency, where values of n were larger, restricted growth strings (RGS) were used to bipartition populations during a nested search (bi-PORGS). Bi-PORGS was applied to a set of genetic data from 18 Chinook salmon (Oncorhynchus tshawytscha) populations from the west coast of Vancouver Island. The optimal grouping of these populations corresponded to four geographic locations: 1) Quatsino Sound, 2) Nootka Sound, 3) Clayoquot +Barkley sounds, and 4) southwest Vancouver Island. However, assignment of populations to groups did not strictly reflect the geographical divisions; fish of Barkley Sound origin that had strayed into the Gold River and close genetic similarity between transferred and donor populations meant groupings crossed geographic boundaries. Overall, stock structure determined by this partitioning method was similar to that determined by the unweighted pair-group method with arithmetic averages (UPGMA), an agglomerative clustering algorithm

Photogrammetry in Mediterranean Archaeology

Digital photogrammetry has progressed to a level at which it no longer requires expensive equipment or significant training in order to produce professional results. In the field of Mediterranean archaeology requirements for documentation and in particular digital documentation are increasing demanding new and innovative means to enable more sites to accomplish these results. During several field seasons working with people of the American School of Classical Studies in Athens, primarily in Ancient Corinth as well as several other Greek sites, modern methods in photogrammetric recording and processing have been explored in an attempt to produce highly accurate, quantifiable three dimensional documentation of archaeological site and artifacts within an extremely limited budget. This thesis explores the craft’s history, methodology and demonstrates using several real world examples how, with little or no money current goals can be achieved and offers a tutorial that can be used by other individuals hoping to produce similar results

A Population-Based Study Comparing Child (0-4) and Adult (55-74) Mortality, GDP-Expenditure on-Health and Relative Poverty in the UK and Developed Countries 1989-2014. Some Challenging Outcomes

Purpose: To compare the UK Child (0-4) and Adult (55-74) Mortality with twenty developed countries 1989-2014 to explore whether the UK has lower priorities for children? Design: WHO data on Child and Adult mortality examined within context of World Bank %GDPExpenditure-on-Health (%GDPEH) data and Income Inequality i.e Relative poverty. Settings: 21 developed countries. Patients: National populations. Outcome Measures: Child and Adult mortality rates per million (pm) population between 1989-2014. Confi dence Intervals compares UK with other developed countries (ODC); odds ratios of average European to UK mortality calculated. Correlations explore links between mortalities, %GDPEH and Income Inequality. Important Results: Highest average 1980-2014 %GDPEH is USA 12.6%, the lowest UK 7.0%. European average 8.5% a UK to European odds ratio 1:1.21. Widest Income Inequality was USA 15.9 times, UK 13.8 was third, European average 8.5times. Child Mortality fell in every country but eleven signifi cantly better than Britain. Highest was USA 1383pm the UK fourth at 967pm. European average 728pm yielded a European to UK odds ratio of 1:1.33. Income Inequality and CRM signifi cantly correlated (RHO=+0.6188 p<0.001) and lowest Private: Public %GDP ratio and highest CMR (Rho=+0.3805 p<0.05). Adult Mortality fell substantially in every country but UK signifi cantly greater reductions than Seventeen counties. European average 9545pm to UK 10,754pm gave a European to UK odds ratio of 1:1.13. Conclusion: Implications; Britain’s results suggest a higher priority is given to adult health than children. The socio-economic context in which UK Child health operates appears to disadvantage UK children, indicating the need to address income inequalities and at least match European average health funding