Category Archives: C#

C#, Matlab, Numerical Algorithms, R, Scientific Computing

Why MINT-students should learn C# instead of Matlab and R

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For students who want to prototype and code, there’s a wide range of domain specific programming languages around: R or Matlab – just to name a few – make it quite easy to design new algorithms, analyze data and to plot complex functions. However, bringing innovation from science to enterprise-ready software applications still costs lots of effort, manpower and experience.

Microsoft’s C# has the potential to fully close this gap: in combination with the ILNumerics numerical library, it becomes the perfect environment both for prototyping and creating powerful software. But why is it that the mainstream in science still doesn’t make use of the power of C#, .NET and Visual studio? Well, let’s have a closer look at computing in academia.

Scientific Computing vs. Real-Life Applications

Like in many other areas in academia, the main reason for sticking to out-of-date techniques is “tradition”. That’s why in 2020 there is still a huge gap between mathematical prototyping and industrial-grade production software. Scientists often aim at creating an algorithm solely in order to validate a new model or theory. Once done, they produce a couple of nice looking plots, publish a paper or two and: bye bye.

Unless… there is a greater use to it!

Turning Prototypes into Products

If a model created in science has the potential to earn serious money,  the algorithm created by a mathematician, physicist or microbiologist has to be transformed into something ‘production ready’ that can be used in real life.

This is where many development teams in the biggest enterprises are stuck today: Everytime they want to adapt innovation from science for their own software applications, they have to translate Matlab, numpy or R codes into a modern, managed SW framework. This transformation is where the pain starts: It has to be done! And not only once, but with each update. This causes a whole lot of redundant and boilerplate code – each and every time. This work is expensive: It requires expert knowledge, extensive testing and additional maintenance. And it significantly delays the time to market!

C# + ILNumerics: Perfect Match for High Performance Applications

This pain needs to stop. And this is where modern general purpose languages come into play. C# for example fulfills all the requirements for the design of numerical algorithms! Developer tools such as Visual Studio – especially if complemented with the ILNumerics Array Visualizer und its highly efficient n-dimensional arrays – allow scientists and software developers to design and prototype their algorithms by directly using production-ready tools.

That means: the painful and time consuming transformation from domain specific prototyping code to an industrial software product is no longer necessary, which allows for huge time savings – often more than 50 percent!

Maths, Physics, Engineering: Boost Innovation now!

However, most established scientists in academia today still stick to Matlab, numpy and R – even though it’s not necessary anymore. But fortunately, a new generation of scientists has started to push innovation at universities ahead. They are often familiar with modern programming languages like C#, and they want to use their knowledge to combine academic prototyping with state of the art software development. This new generation will modernize the intersections between science and industry. Their skills will allow companies all over the world to realize all their innovative potential in a much shorter period of time.

That’s why we think any science and engineering student should get familiar with modern programming languages as early as possible: It will help him or her to boost innovation in their field all over the world!

.NET, C#, Interesting/ useless

Fun with Visual Studio regexp search

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I only recently realized that the Visual Studio regexp feature in Search & Replace is even able to handle regexp captures. Example: In order to locate and replace all line endings in your code which exist at the end of non-empty lines, exluding lines which end at ‘/’ or with other non-alphanumeric characters one can use:

Search Pattern: ([0-9a-zA-Z)])\r\n
Replace: $1;\r\n

searchandreplacevisualstudioMatches inside () parenthesis are captured. When it comes to replacing the match the new value is created by first inserting the captured value at the position marked by ‘$1′. This way it it possible to, let’s say insert a new char in the middle of a search pattern – if it fulfills certain conditions.

There appears to be an error in the MSDN documentation, unfortunately at the point describing how to reference captures in Visual Studio regexp replace patterns. Anyway, using the ‘$’ char in conjunction with the index is the common way and it works here just fine.

Multiple captures are possible as well. Just refer to the captured content by the index according to the count of ‘()’ captures in the search pattern.

The Visual Studio regexp support is really helpful when translating huge C header files to C# – to name only one situations. It saved me a huge amount of time already. Hope you find this useful too.

.NET, C#, ILNumerics, Matlab

HDF5 and Matlab Files – Fun with ILNumerics

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Why to use HDF5 and ILNumerics?

HDF5 is a file format (Hierarchical Data Format) especially desgined to handle huge amount of numerical data. Just to mention an example,  NASA chose it to be the standard file format for storing data from the Earth Observing System (EOS).

ILNumerics easily handles HDF5 files. They can be used to exchange data with other software tools, for example Matlab mat files. In this post I will show a step by step guide – how to interface ILNumerics with Matlab.

Continue reading HDF5 and Matlab Files – Fun with ILNumerics →

.NET, C#, Features, ILNumerics, Interesting/ useless, Scientific Computing, Visualization

ILNumerics for Scientists – Going 3D

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Recap

Last time I started with one of the easiest problems in quantum mechanics: the particle in a box. This time I’ll add 1 dimension and we’ll see a particle in a 2D box. To visualize its wave function and density we need 3D surface plots.

2D Box

This time we have a particle that is confined in a 2D box. The potential within the box is zero and outside the box infinity. Again the solution is well-known and can be found on Wikipedia. This time the state of the wave function is determined by two numbers. These are typically called quantum numbers and refer to the X and the Y direction, respectively.

The absolute size of the box doesn’t really matter and we didn’t worry about it in the 1D case. However, the relative size of the length and the width make a difference. The solution to our problem reads

$\Psi_{n,k}(x,y) = \sqrt{\frac{4}{L_x L_y}} \cdot \sin(n \cdot \pi \cdot x / L_x) \cdot \sin(k \cdot \pi \cdot y / L_y)$

The Math

Very similar to the 1D case I quickly coded the wave function and the density for further plotting. I had to make sure that the arrays are fit for 3D plotting, so the code looks a little bit different compared to last post’s

     public static ILArray<double> CalcWF(int EVXID, int EVYID, double LX, double LY, int MeshSize)
     {
        ILArray<double> X = linspace<double>(0, LX, MeshSize);
        ILArray<double> Y = linspace<double>(0, LY, MeshSize);

        ILArray<double> Y2d = 1;
        ILArray<double> X2d = meshgrid(X, Y, Y2d);

        ILArray<double> Z = sqrt(4.0 / LX / LY) * sin(EVXID * pi * X2d / LX) * sin(EVYID * pi * Y2d / LY);

        return Z.Concat(X2d,2).Concat(Y2d,2);
     }

Again, this took me like 10 minutes and I was done.

The Visualization

This time the user can choose the quantum numbers for X and Y direction, the ratio between the length and the width of the box and also the number of mesh points along each axis for plotting. This makes the visualization panel a little bit more involved. Nevertheless, it’s still rather simple and easy to use. This time it took me only 45 minutes – I guess I learned a lot from last time.

The result

Here is the result of my little program. You can click and play with it. If you’re interested, you can download the Particle2DBox source code. Have fun!

Particle2DBoxThis is a screenshot of the application. I chose the second quantum number along the x axis and the fourth quantum number along the y axis. The box is twice as long in y direction as it is in x direction. The mesh size is 100 in each direction. On the left hand side you see the wave function and on the right hand side the probability density.

C#, ILNumerics, Scientific Computing, Usage

Directions to the ILNumerics Optimization Toolbox

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As of yesterday the ILNumerics Optimization Toolbox is out and online! It’s been quite a challenge to bring everything together: some of the best algorithms, the convenience you as a user of ILNumerics expect and deserve, and the high performance requirements ILNumerics sets the scale on for. We believe that all these goals could be achieved quite greatly.

Continue reading Directions to the ILNumerics Optimization Toolbox →

.NET, C#, ILNumerics, Scientific Computing

ILNumerics for Scientists – An easy start

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Motivation

I’ve been working as a scientist at universities for 10 years before deciding to go into industry. The one thing I hated most was coding. At the end of the day coding for scientists is like running for a football player. Obviously, you need it but it’s not what you’re here for.

I really dreaded the coding and the debugging. So much precious time for something that was so clear on paper and I just wanted the solution of my equations to see whether my idea made sense or not. More often than not scientists find that their idea was not so great and now they had spent so much time coding just to find out that the idea didn’t work. Continue reading ILNumerics for Scientists – An easy start →

C#, ILNumerics, Usage, Visualization

Getting to know your Scene Graph

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Did you ever miss a certain feature in your ILNumerics scene graph? You probably did. But did you know, that most of the missing “features” mean nothing more than a missing “property”? Often enough, there is only a convenient access to a certain scene graph object needed in order to finalize a required configuration.

Recently, a user asked how to turn the background of a legend object in ILNumerics plots transparent. There doesn’t seem to be a straight forward way to that. One might expect code like the following to work:

var legend = new ILLegend("Line 1", "Line 2");
legend.Background.Color = Color.FromArgb(200, Color.White);

Continue reading Getting to know your Scene Graph →

C#, ILNumerics, Usage

Uncommon data conversion with ILArray

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ILNumerics Computing Engine supports the most common numeric data types out of the box: double, float, complex, fcomplex, byte, short, int, long, ulong

If you need to convert from, let’s say ushort to float, you will not find any prepared conversion function in ILMath. Luckily, it is very easy to write your own:

Here comes a method which implements the conversion from ushort -> float. A straight forward version first:

        /// <summary>
        /// Convert ushort data to ILArray&lt;float>
        /// </summary>
        /// <param name="A">Input Array</param>
        /// <returns>Array of the same size as A, single precision float elements</returns>
        public static ILRetArray<float> UShort2Single(ILInArray<ushort> A) {
            using (ILScope.Enter(A)) {
                ILArray<float> ret = ILMath.zeros<float>(A.S);
                var retArr = ret.GetArrayForWrite();
                var AArr = A.GetArrayForRead();
                int c = 0;
                foreach (ushort a in A) {
                    retArr[c++] = a;
                }
                return ret;
            }
        }

Continue reading Uncommon data conversion with ILArray →