Continuing the introduction of the new features coming soon with the next release of LabPlot (see the previous blogs here and here), we want to share today some news about the developments we did for the data fitting (linear and non-linear regression analysis) in the last couple of months.
Data fitting, one of the most common and frequently used data analysis tasks, got a lot of improvements. As already mentioned in the previous blog, all analysis functions benefited from the recent general UX improvements. Instead of going through the many manual steps, the final fit result can now be quickly produced via the context menu of the data spreadsheet or directly in the plot in the context menu of the data curve:
Until now, the fit parameters could in principle take any values allowed by the fit model, which would lead to a reasonable description of the data. However, sometimes the realistic regions for the parameters are known in advance and it is desirable to set some mathematical constrains on them. LabPlot provides now the possibility to define lower and/or upper bounds for the fit parameters and to limit the internal fit algorithm to these regions only. Also, it is possible now to fix parameters to certain already known values:
Some consistency checks were implemented to notify the user about wrong inputs (upper bound is smaller than the lower bound, start value is outside of the bounds, etc.) immediately.
The internal parser for the mathematical expressions learnt to recognize arbitrary user-defined parameters. With this, the fit parameters of custom models are automatically determined and there is no need for the user anymore to explicitly specify the parameter names manually once more when providing the start values and the constraints for them.
To obtain the improved parameter estimators for data where the error in the measurements is not constant across the different data points, fitting with weights is used usually as one of the methods to account for such unequal distributions of errors. Fitting with weights is supported in LabPlot now. Different weighting methods are available to ensure the appropriate level of influence of the different errors on the final estimation of the fit parameters. Furthermore, the errors for both, the x- and y-data points, can be accounted for.
The representation of the fit results was extended. In addition to what was already available in the previous release of LabPlot for the goodness of the fit, new criteria were added like t and p values, the probability that the null hypothesis in the t-test is true, confidence intervals, Akaike- and Bayesian information criteria. The screenshot below shows the current version of the fit dock widget:
Though quite a lot of features are already available in LabPlot in this area, many important and useful features like the support for different fitting algorithms, the subtractions of baseline from a spectrum, etc. need to be implemented. We hope to close the open gaps here very soon in one of the next releases.
01.03.2016 SWARCO TRAFFIC SYSTEMS GIVES THE GREEN LIGHT TO QNX "Leader in intelligent traffic systems chooses the QNX Neutrino OS for its ACTROS family of traffic light controllers. Nuremburg, Embedded World 2016, Hall 4, Booth 534 mdash; February 23 mdash; QNX Software Systems Limited, a subsidiary of BlackBerry Limited, today announced that SWARCO TRAFFIC SYSTEMS GmbH has chosen the QNXreg; Neutrinoreg; Realtime OS for its ACTROS family of traffic light controllers. ACTROS controllers bring an intelligent approach to managing urban traffic. They are designed to enhance safety, optimize the use of existing road infrastructure, and improve traffic flow to...01.06.2011 The New Way to Work… Part 2 The New Way to Work… Part 2 Posted by Steve HerrodChief Technology Officer In April I introduced VMware’s acquisition of SlideRocket with a blog entry entitled, “The New Way to Work – End-User Computing in the Post-PC Era”. Today I am happy to announce the next step in this journey with our acquisition of Socialcast, a powerful “Enterprise Activity Stream Engine” that unites a company’s people, information, and applications in real-time. In this blog, I discuss this social platform and how it helps evolve the way we work. First, let’s step back and look at today’s approach to enterprise com...04.11.2011 Comparing ESXi 4.1 and ESXi 5.0 Scaling Performance Comparing ESXi 4.1 and ESXi 5.0 Scaling Performance In previous articles on VROOM! we used VMmark 2 to investigate the effects of altering a single hardware component, such as a storage array or server model, in a vSphere cluster. In contrast to these earlier studies, we now examine the effects of upgrading the hosts’ software from ESXi 4.1 to ESXi 5.0 on the performance of a VMmark 2 cluster. vSphere 5 includes many new features and virtual machine enhancements, the details of which can be found here. To the IT professional weighing the costs and benefits of upgrading their existing infra...22.11.2011 New Articles Published for Week Ending 11/19/11 New Articles Published for Week Ending 11/19/11 Apache HTTP Server Logging user defined cookies with Apache 2.0 and the usertrack module (2008211) Date Published: 11/14/2011 Checking the modules that are compiled into Apache HTTP Server and vFabric Enterprise Server (2009272) Date Published: 11/17/2011 Installing mod_fcgid on Apache HTTP Server 2.0.x configurations under Linux/Unix (2009475) Date Published: 11/17/2011 Apache Tomcat Setting up Tomcat in the Windows platform for monitoring by jconsole or jvisualvm (2008410) Date Published: 11/15/2011 Enabling garbage collection logging with T...12.05.2010 Surveying Virtualization Performance Trends with VMmark Surveying Virtualization Performance Trends with VMmark The trends in published VMmark scores are an ideal illustration of the historical long-term performance gains for virtualized platforms. We began work on what would become VMmark 1.0 almost five years ago. At the time, ESX 2.5 was the state-of-the-art hypervisor. Today’s standard features such as DRS, DPM, and Storage VMotion were in various prototype and development stages. Processors like the Intel Pentium4 5xx series (Prescott) or the single-core AMD 2yy-series Opterons were the high-end CPUs of choice. Second-generation hardware-...05.11.2015 QRegExp + QStringLiteral = crash at exit QRegExp will cache the string in a Q_GLOBAL_STATIC variable, and remember that because it's a QStringLiteral , it has it's data in .rodata of your KDE library . When you exit the application, your KDE library gets unloaded then QtCore get unloaded.29.12.2015 Luxoft Teams Up with QNX on Automotive ADAS Technologies "Collaboration focused on advanced technologies, including road scene reconstruction and augmented navigation, which can enable semiautonomous driving.December 15, 2015 Luxoft Holding, Inc. NYSE:LXFT, a leading provider of software development services and innovative IT solutions to a global client base, and QNX Software Systems Limited, a subsidiary of BlackBerry Limited, today announced a new technology partnership focused on ADAS systems used by automotive original equipment manufacturers OEMs and Tier 1 suppliers. As part of the initiative, Luxoft will leverage its expertise in road-model...12.01.2016 QNX INTRODUCES HOLISTIC APPROACH TO MANAGING IN-CAR ACOUSTICS "New platform offers unified management of all acoustics in the car, enabling customers to reduce the cost, complexity, and time-to-production of audio signal-processing systems. Las Vegas, International CES 2016, LVCC North Hall, Booth 325 - January 6 - QNX Software Systems Limited, a subsidiary of BlackBerry Limited, today announced the new QNXreg; Acoustics Management Platform AMP, a comprehensive solution that allows automakers to enhance the audio and acoustic experience for drivers and passengers, while reducing system costs and complexity.Modern vehicles contain multiple acoustic and au...13.05.2008 Partner Comments on VMware Site Recovery Manager “3PAR’s virtualized storage and easy-to-implement remote copy software make it possible for organizations to cost effectively protect more data without complexity,” said Craig Nunes, Vice President of Marketing at 3PAR. “3PAR is working with VMware to ensure that our customers will be able to use VMware Site Recovery Manager with 3PAR’s InServ storage systems to further increase the reliability and decrease the complexity of their disaster recovery deployments.”
“Dell customers are leveraging VMware virtualization across their data centers to enjoy the availability, manageability and flexibili...28.02.2008 Backup Software Compatibility For ESX Server 3.0.x http://www.vmware.com/pdf/vi3_backup_guide.pdf Last Updated: February 27, 2008 What’s New Changes since the last edition of this guide include: Modified support information for HP Data Protector 5.5 and 6.0. See “Supported backup software,” on page 3.