I recently had an honor to join JKI, a San Francisco based LabVIEW consulting and software company well known among international LabVIEW developer community. JKI is probably best known of its dream team of LabVIEW developers and its rich set of innovative tools for LabVIEW developer community. I am really excited for the opportunity to be able to work together with such an outstanding team and I am looking forward to learn a lot from maybe the best LabVIEW developers in the world. At the same time I am confident I can bring new perspective to the JKI team and together we can come up with new exciting solutions for both the JKI consulting customers and the LabVIEW developer community.

ExpressionFlow has reached the milestone of total 100,000 visits since the launch of the site three years ago.  I would like to thank all of you for following ExpressionFlow. I work hard to make ExpressionFlow even more interesting. What kind of subjects would you like to hear more about?

In my previous post I introduced the design pattern of worker pool based on dataflow recursion. In this post the pattern is revisited. I explain the theoretical concept of unlimited parallelism and concurrency that is a consequence of recursion in dataflow based programming languages. Furthermore I present how worker threads can be reused to manage system resource consumption.

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Creating parallel code in LabVIEW is simple; simply place parallel tasks parallel on VI block diagram and the tasks are executed in parallel. However this design doesn’t bend to use cases when the number of parallel tasks is not known at development time but needs to be specified at runtime.  In this post I present simple design pattern for parallel code execution based on recursion. In my next post I study the recursive concurrency in more detail.

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Many modern programming languages implement generic programming support with the concept of type parameters. Generic programming using type parameters is the feature I have been missing the most in LabVIEW. Generic programming is about writing reusable blocks of code in terms of types that are specified in later time. In LabVIEW terminology type parameters would specify the type of wires and terminals of generic type. Type parameters can either be implicit or explicit. Implicit type parameters are determined by the compiler automatically where as explicit type parameters are specified by the developer. Furthermore type parameters can have variation limits, specifying what kind of type are accepted. Type parameters could be in principle applied to a VI, to a class, to a library, to a mixin class (trait), to an interface or any other kind of module that includes executable code or front panels. (EDITED Introduction & title 10/25/2009 9:36 GMT)

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I was today attending LabVIEW Developer Education Day in Helsinki (Espoo), Finland. The NI application engineer was introducing the new parallel for-loop structure released in LabVIEW 2009. The idea is that a for-loop iterations can be run in parallel when the loop iterations do not depend on one another. The concept is nice and I have been waiting for NI to introduce such a concept for some years. I was positively surprised when I noticed that LabVIEW 2009 is shipping with this new feature.

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Dear ExpressionFlow readers and fellow LabVIEW developers. I’m very excited to tell you, that recently I’ve founded a new Helsinki based company, Agile 4, providing LabVIEW software development related consultation services. Today, it’s time to come out of the shadows and public with the company.

Agile 4 Ltd. is a software design, development, and software strategy consulting start-up specialized in building state-of-the-art LabVIEW based technology solutions. We are comitted to providing our customers with the best possible software solutions and world class software expertise.

We at Agile 4 are enthusiastic about software development with LabVIEW. We want to help our customers succeed in their business environment by helping them to make the best possible software solutions for their market. We understand that software development is an investment and we think our customers should get the best value for their software related investments.

ExpressionFlow will continue to as a LabVIEW and visual programming blog. I’ll do my best to keep posting articles on subjects close to me and Agile 4.

For more information on the company, please visit Agile 4 website.

Today I transferred ExpressionFlow from my old shared hosting provider to Mosso hosting cloud. If you are experiencing any problems, please report them so I can get the problems fixed.

Mosso is a kind of hybrid solution. You get the easiness of shared hosting together with the power of a cloud. During the last six months I’ve been using Mosso to host several different web sites, and I must say I’ve been impressed by the simply superb customer service they have. When ever I’ve had any troubles at all, my problems are solved immediately by the very helpful and skilled customer service. I can’t say the same of my old hosting provider. For fixed price a month you can host an unlimited number of web sites on both Windows and Linux hosts limited only by the total consumed system resources a month. Actually, the only thing I’ve been missing is a hosting plan with less capacity than the only current hosting plan they’re providing. If you are interested in test driving Mosso, use the referral code REF-EXPRESSIONFLOW at sign-up and you’ll get $50 credit.

A leap second will be added at the end of the year 2008. That is after 23:59:59, a positive leap second at 23:59:60 would be counted, before the clock indicates 00:00:00 of the first day of 2009. The addition of a leap second may mesh up with the time synchronization of your software and your application may end up functioning in an unpredictable way. more…

How many times you have seen an error message window to pop-up in an application giving you a meaningless error message and all you can do is to press “Ok” or “Cancel” without any idea where the error message was related to. At best the error message gives you some hint what was wrong and you may get back on track with the application. However once you close the pop-up, you no longer have the details of the error message to help you with fixing the problem. Do the applications you yourself have developed behave this way?

Well, things don’t have to be this way? On the contrary, you as a developer should design applications so that you never let your users to find  themselves in situations like this. It’s not only a benefit of the user, but also a benefit of you as a developer. Once your applications works fluently and gives your users intuitive feedback, you need to spend much less time for the user support and you’ll have much more time for your most important tasks.

One way to increase the usability of your application is to avoid pop-up windows altogether and instead display contextual error-messages in-place as close to the actual point-of-problem as possible. For example, when you have a user editable string control, your application should display the error message right next to the string control and instruct the user right away fix the problem occurred.

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