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A Look at KDE's KAlgebra

1 week 4 days ago
by Joey Bernard

Many of the programs I've covered in the past have have been desktop-environment-agnostic—all they required was some sort of graphical display running. This article looks at one of the programs available in the KDE desktop environment, KAlgebra.

You can use your distribution's package management system to install it, or you can use Discover, KDE's package manager. After it's installed, you can start it from the command line or the launch menu.

When you first start KAlgebra, you get a blank slate to start doing calculations.

Figure 1. When you start KAlgebra, you get a blank canvas for doing calculations.

The screen layout is a large main pane where all of the calculations and their results are displayed. At the top of this pane are four tabs: Calculator, 2D Graph, 3D Graph and Dictionary. There's also a smaller pane on the right-hand side used for different purposes for each tab.

In the calculator tab, the side pane gives a list of variables, including predefined variables for things like pi or euler, available when you start your new session. You can add new variables with the following syntax:

a := 3

This creates a new variable named a with an initial value of 3. This new variable also will be visible in the list on the right-hand side. Using these variables is as easy as executing them. For example, you can double it with the following:

a * 2

There is a special variable called ans that you can use to get the result from your most recent calculation. All of the standard mathematical operators are available for doing calculations.

Figure 2. KAlgebra lets you create your own variables and functions for even more complex calculations.

There's also a complete set of functions for doing more complex calculations, such as trigonometric functions, mathematical functions like absolute value or floor, and even calculus functions like finding the derivative. For instance, the following lets you find the sine of 45 degrees:

sin(45)

You also can define your own functions using the lambda operator ->. If you want to create a function that calculates cubes, you could do this:

x -> x^3

This is pretty hard to use, so you may want to assign it to a variable name:

cube := x -> x^3

You then can use it just like any other function, and it also shows up in the list of variables on the right-hand side pane.

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Joey Bernard

Android Apps Riskier Than Ever: Report

1 week 4 days ago
Widespread use of unpatched open source code in the most popular Android apps distributed by Google Play has caused significant security vulnerabilities, suggests an American Consumer Institute report. Thirty-two percent -- or 105 apps out of 330 of the most popular apps in 16 categories sampled -- averaged 19 vulnerabilities per app, according to the report. Researchers found critical vulnerabilities in many common applications.
Jack M. Germain

Support for a LoRaWAN Subsystem

1 week 5 days ago
by Zack Brown

Sometimes kernel developers find themselves competing with each other to get their version of a particular feature into the kernel. But sometimes developers discover they've been working along very similar lines, and the only reason they hadn't been working together was that they just didn't know each other existed.

Recently, Jian-Hong Pan asked if there was any interest in a LoRaWAN subsystem he'd been working on. LoRaWAN is a commercial networking protocol implementing a low-power wide-area network (LPWAN) allowing relatively slow communications between things, generally phone sensors and other internet of things devices. Jian-Hong posted a link to the work he'd done so far: https://github.com/starnight/LoRa/tree/lorawan-ndo/LoRaWAN.

He specifically wanted to know "should we add the definitions into corresponding kernel header files now, if LoRaWAN will be accepted as a subsystem in Linux?" The reason he was asking was that each definition had its own number. Adding them into the kernel would mean the numbers associated with any future LoRaWAN subsystem would stay the same during development.

However, Marcel Holtmann explained the process:

When you submit your LoRaWAN subsystem to netdev for review, include a patch that adds these new address family definitions. Just pick the next one available. There will be no pre-allocation of numbers until your work has been accepted upstream. Meaning, that the number might change if other address families get merged before yours. So you have to keep updating. glibc will eventually follow the number assigned by the kernel.

Meanwhile, Andreas Färber said he'd been working on supporting the same protocol himself and gave a link to his own proof-of-concept repository: https://github.com/afaerber/lora-modules.

On learning about Andreas' work, Jian-Hong's response was, "Wow! Great! I get new friends :)"

That's where the public conversation ended. The two of them undoubtedly have pooled their energies and will produce a new patch, better than either of them might have done separately.

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Zack Brown

The First Beta of the /e/ OS to Be Released Soon, Canonical's Security Patch for Ubuntu 18.04 LTS, Parrot 4.2.2 Now Available, Open Jam 2018 Announced and Lightbend's Fast Data Platform Now on Kubernetes

1 week 5 days ago

News briefs for September 12, 2018.

Gaël Duval writes that the first beta of the /e/ OS will be released soon. See his post for more information on how to test it and a list of supported Android devices.

Canonical yesterday released a Linux kernel security patch for Ubuntu 18.04 LTS that addresses two recnetly discovered vulnerabilities. See Softpedia News for more information, and update now if you haven't already.

Parrot, the Debian-based distro for "security experts, developers and crypto-addicted people", released verion 4.2.2 this week. This new version is powered by the latest 4.18 kernel and features a new version of the Debian-Installer, updated firmware packages, the latest LibreOffice 6.1 release, Firefox 62 and more. See the release notes for all the updates.

Open Jam, the open-source game jam, will run this year from October 5–8th: "Participants will build an open source game from scratch in 80 hours, play and judge other games, and compete for a chance to have their game featured at All Things Open." See the announcement on Opensource.com for all the details and how to participate.

Lightbend announced yesterday that version 2.0 of its Fast Data Platform is now available on Kubernetes, making it the "most complete platform for developing and operating microservices-based AI, ML, IoT and other streaming data-based applications. Visit the Lightbend website for more information.

News /e/ Android Mobile Canonical Ubuntu Security Parrot gaming Kubernetes
Jill Franklin