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  • Is there a recommended way to communicate scientific/engineering programming to C developers?

    - by ggkmath
    Hi, I have a lot of MATLAB code that needs to get ported to C (execution speed is critical for this work) as part of a back-end process for a web application. When I attempt to outsource this code to a C developer, I assume (correct me if I'm wrong) few C developers also understand MATLAB code (things like indexing and memory management are different, etc.). I wonder if there are any C developers out there that can recommend a procedure for me to follow to best communicate what the code does? For example, should I provide the MATLAB code and explain what it's doing line by line? Or, should I just provide the math/algorithm, explain it in plain English, and let the C developer implement it with this understanding in his/her own way (e.g. can I assume the developer understands how to work with complex math (i.e. imaginary numbers), how to generate histograms, perform an FFT, etc.)? Or, is there a better method? I expect I'm not the first to need to do this, so I wonder if any C developers out there ran into this situation and can share any conventional wisdom how they'd like this task to be transferred? Thanks in advance for any comments.

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  • How to automatically insert a class notation using eclipse templates?

    - by João Paulo G. Piccinini
    Does anybody know how to insert a "@RunWith anotation" above the class signature, using eclipse templates? Ex.: @RunWith(Parameterized.class) public class MyClassTest { ... @Parameters public static Collection<Object[]> parameters() { List<Object[]> list = new ArrayList<Object[]>(); list.add(new Object[] { "mind!", "find!" }); list.add(new Object[] { "misunderstood", "understood" }); return list; } ... } __ Template: // TODO: move this '@RunWith(Parameterized.class)' to class anotation @Parameters public static Collection<Object[]> parameters() { ${type:elemType(collection)}<Object[]> parametersList = new ${type:elemType(collection)}<Object[]>(); ${cursor}// TODO: populate collection return parametersList; } __ Thanks for the help!

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  • When to use memberEnd and when navigableOwnedEnd (in Altova notation) in an UML class diagram?

    - by Ivan
    I've download a trial of Altova UModel and am starting using UML. As a practical beginning I am modelling a personal information manager application, which includes a web bookmark managing. A Bookmark can belong to many (or no) Tags at once and a Tag can contain many (or no if all the bookmarks it contained were deleted) bookmarks. The relation has to be both-way navigable - a user has to be able to see all Bookmarks with a particular Tags ans all Tags of a Bookmark. What is the correct UML relation between Bookmark and Tag classes? As far as I understand UML now, it is an Association (not an Aggregation). But for a 2-way navigable many-to-many relation I can specify ends roles as "memberEnd" or "when navigableOwnedEnd", graphically the connection looks the same in both cases (an arrow) (which as I understand means navigability) but a property appears in the class box in case only when "memberEnd" is used. How should I specif it in the model If I mean both-way navigable many-to-many relation there?

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  • Adaptive Case Management Modeling with CMMN by Jessica Ray

    - by JuergenKress
    A new version of Oracle BPM Suite 11.1.1.7 with Adaptive Case Management (ACM) is now available, so what will that mean for requirements gathering? BPM project requirements can be documented using Business Process Model and Notation (BPMN 2.0). For ACM, there is a new notation in the works. It is called Case Management Model and Notation (CMMN). For now, this notation isn’t included as a modeling tool in the new version of Oracle BPM Suite 11.1.1.7 with ACM, but it is possible that a modeling tool could be included in a future release. What is CMMN? CMMN is a standard intended to capture the common elements that Case Management Products use, the same way that BPMN is a standard for BPM products (such as Oracle BPM). CMMN is created by the Object Management Group (OMG) and is still in the beta version. In April 2014, OMG released the second beta version the CMMN 1.0, and the most recent version is available here. CMMN captures some of the elements that are commonly used when talking about ACM such as Cases, Milestones, and Tasks. It also introduces some elements that you may not automatically hear when talking about ACM such as Stages, Events, and Decorators. Here is a quick summary at a few (but not all) of the elements of CMMN taken from the CMMN spec. A Few CMMN Elements Read the complete article here SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Technorati Tags: Jessica Ray,Avio,Adaptive Case Management,ACM,CMMN,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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  • Why do apache2 upgrades remove and not re-install libapache2-mod-php5?

    - by nutznboltz
    We repeatedly see that when an apache2 update arrives and is installed it causes the libapache2-mod-php5 package to be removed and does not subsequently re-install it automatically. We must subsequently re-install the libapache2-mod-php5 manually in order to restore functionality to our web server. Please see the following github gist, it is a contiguous section of our server's dpkg.log showing the November 14, 2011 update to apache2: https://gist.github.com/1368361 it includes 2011-11-14 11:22:18 remove libapache2-mod-php5 5.3.2-1ubuntu4.10 5.3.2-1ubuntu4.10 Is this a known issue? Do other people see this too? I could not find any launchpad bug reports about it. Platform details: $ lsb_release -ds Ubuntu 10.04.3 LTS $ uname -srvm Linux 2.6.38-12-virtual #51~lucid1-Ubuntu SMP Thu Sep 29 20:27:50 UTC 2011 x86_64 $ dpkg -l | awk '/ii.*apache/ {print $2 " " $3 }' apache2 2.2.14-5ubuntu8.7 apache2-mpm-prefork 2.2.14-5ubuntu8.7 apache2-utils 2.2.14-5ubuntu8.7 apache2.2-bin 2.2.14-5ubuntu8.7 apache2.2-common 2.2.14-5ubuntu8.7 libapache2-mod-authnz-external 3.2.4-2+squeeze1build0.10.04.1 libapache2-mod-php5 5.3.2-1ubuntu4.10 Thanks At a high-level the update process looks like: package package_name do action :upgrade case node[:platform] when 'centos', 'redhat', 'scientific' options '--disableplugin=fastestmirror' when 'ubuntu' options '-o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"' end end But at a lower level def install_package(name, version) run_command_with_systems_locale( :command = "apt-get -q -y#{expand_options(@new_resource.options)} install #{name}=#{version}", :environment = { "DEBIAN_FRONTEND" = "noninteractive" } ) end def upgrade_package(name, version) install_package(name, version) end So Chef is using "install" to do "update". This sort of moves the question around to "how does apt-get safe-upgrade" remember to re-install libapache-mod-php5? The exact sequence of packages that triggered this was: apache2 apache2-mpm-prefork apache2-mpm-worker apache2-utils apache2.2-bin apache2.2-common But the code is attempting to run checks to make sure the packages in that list are installed already before attempting to "upgrade" them. case node[:platform] when 'debian', 'centos', 'fedora', 'redhat', 'scientific', 'ubuntu' # first primitive way is to define the updates in the recipe # data bags will be used later %w/ apache2 apache2-mpm-prefork apache2-mpm-worker apache2-utils apache2.2-bin apache2.2-common /.each{ |package_name| Chef::Log.debug("is #{package_name} among local packages available for changes?") next unless node[:packages][:changes].keys.include?(package_name) Chef::Log.debug("is #{package_name} available for upgrade?") next unless node[:packages][:changes][package_name][:action] == 'upgrade' package package_name do action :upgrade case node[:platform] when 'centos', 'redhat', 'scientific' options '--disableplugin=fastestmirror' when 'ubuntu' options '-o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"' end end tag('upgraded') } # after upgrading everything, run yum cache updater if tagged?('upgraded') # Remove old orphaned dependencies and kernel images and kernel headers etc. # Remove cached deb files. case node[:platform] when 'ubuntu' execute 'apt-get -y autoremove' execute 'apt-get clean' # Re-check what updates are available soon. when 'centos', 'fedora', 'redhat', 'scientific' node[:packages][:last_time_we_looked_at_yum] = 0 end untag('upgraded') end end But it's clear that it fails since the dpkg.log has 2011-11-14 11:22:25 install apache2-mpm-worker 2.2.14-5ubuntu8.7 on a system which does not currently have apache2-mpm-worker. I will have to discuss this with the author, thanks again.

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  • Construction Paper, Legos, and Architectural Modeling

    I can remember as a kid playing with construction paper and Legos to explore my imagination. Through my exploration I was able to build airplanes, footballs, guns, and more, out of paper. Additionally I could create entire cities, robots, or anything else I could image out of Legos.  These toys, I now realize were in fact tools that gave me an opportunity to explore my ideas in the physical world through the use of modeling.  My imagination was allowed to run wild as I, unknowingly at the time, made design decisions that directly affected the models I was building from the raw materials.  To prove my point further, I can remember building a paper airplane that seemed to go nowhere when I tried to throw it. So I decided to attach a paper clip to the plane before I decided to throw it the next time to test my concept that by adding more weight to the plane that it would fly better and for longer distances. The paper airplane allowed me to model my design decision through the use of creating an artifact in that I created a paper airplane that was carrying extra weight through the incorporation of the paper clip in to the design. Also, I remember using Legos to build all sorts of creations, and these creations became artifacts of my imagination. As I further and further defined my Lego creations through the process of playing I was able to create elaborate artifacts of my imagination. These artifacts represented design decision I had made in the evolution of my creation through my child like design process. In some form or fashion the artifacts I created as a kid are very similar to the artifacts that I create when I model a software architectural concept or a software design in that the process of making decisions is directly translated in to a tangible model in the form of an architectural model. Architectural models have been defined as artifacts that depict design decisions of a system’s architecture.  The act of creating architectural models is the act of architectural modeling. Furthermore, architectural modeling is the process of creating a physical model based architectural concepts and documenting these design decisions. In the process of creating models, the standard notation used is Architectural modeling notation. This notation is the primary method of capturing the essence of design decisions regarding architecture.  Modeling notations can vary based on the need and intent of a project; typically they range from natural language to a diagram based notation. Currently, Unified Markup Language (UML) is the industry standard in terms of architectural modeling notation  because allows for architectures to be defined through a series of boxes, lines, arrows and other basic symbols that encapsulate design designs in to virtual components, connectors, configurations and interfaces.  Furthermore UML allows for additional break down of models through the use of natural language as to explain each section of the model in plain English. One of the major factors in architectural modeling is to define what is to be modeled. As a basic rule of thumb, I tend to model architecture based on the complexity of systems or sub sub-systems of architecture. Another key factor is the level of detail that is actually needed for a model. For example if I am modeling a system for a CEO to view then the low level details will be omitted. In comparison, if I was modeling a system for another engineer to actually implement I would include as much detailed information as I could to help the engineer implement my design.

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  • is the + in += on a Map a prefix operator of =?

    - by Steve
    In the book "Programming in Scala" from Martin Odersky there is a simple example in the first chapter: var capital = Map("US" -> "Washington", "France" -> "Paris") capital += ("Japan" -> "Tokyo") The second line can also be written as capital = capital + ("Japan" -> "Tokyo") I am curious about the += notation. In the class Map, I didn't found a += method. I was able to the same behaviour in an own example like class Foo() { def +(value:String) = { println(value) this } } object Main { def main(args: Array[String]) = { var foo = new Foo() foo = foo + "bar" foo += "bar" } } I am questioning myself, why the += notation is possible. It doesn't work if the method in the class Foo is called test for example. This lead me to the prefix notation. Is the + a prefix notation for the assignment sign (=)? Can somebody explain this behaviour?

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  • Please help me give this principle a name

    - by Brent Arias
    As a designer, I like providing interfaces that cater to a power/simplicity balance. For example, I think the LINQ designers followed that principle because they offered both dot-notation and query-notation. The first is more powerful, but the second is easier to read and follow. If you disagree with my assessment of LINQ, please try to see my point anyway; LINQ was just an example, my post is not about LINQ. I call this principle "dial-able power". But I'd like to know what other people call it. Certainly some will say "KISS" is the common term. But I see KISS as a superset, or a "consumerism" practice. Using LINQ as my example again, in my view, a team of programmers who always try to use query notation over dot-notation are practicing KISS. Thus the LINQ designers practiced "dial-able power", whereas the LINQ consumers practice KISS. The two make beautiful music together. I'll give another example. Imagine a C# logging tool that has two signatures allowing two uses: void Write(string message); void Write(Func<string> messageCallback); The purpose of the two signatures is to fulfill these needs: //Every-day "simple" usage, nothing special. myLogger.Write("Something Happened" + error.ToString() ); //This is performance critical, do not call ToString() if logging is //disabled. myLogger.Write( () => { "Something Happened" + error.ToString() }); Having these overloads represents "dial-able power," because the consumer has the choice of a simple interface or a powerful interface. A KISS-loving consumer will use the simpler signature most of the time, and will allow the "busy" looking signature when the power is needed. This also helps self-documentation, because usage of the powerful signature tells the reader that the code is performance critical. If the logger had only the powerful signature, then there would be no "dial-able power." So this comes full-circle. I'm happy to keep my own "dial-able power" coinage if none yet exists, but I can't help think I'm missing an obvious designation for this practice. p.s. Another example that is related, but is not the same as "dial-able power", is Scott Meyer's principle "make interfaces easy to use correctly, and hard to use incorrectly."

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  • Is this high coupling?

    - by Bono
    Question I'm currently working a on an assignment for school. The assignment is to create a puzzle/calculator program in which you learn how to work with different datastructures (such as Stacks). We have generate infix math strings suchs as "1 + 2 * 3 - 4" and then turn them in to postfix math strings such as "1 2 + 3 * 4 -". In my book the author creates a special class for converting the infix notation to postfix. I was planning on using this but whilst I was about to implement it I was wondering if the following is what you would call "high coupling". I have read something about this (nothing that is taught in the book or anything) and was wondering about the aspect (since I still have to grasp it). Problem I have created a PuzzleGenerator class which generates the infix notation of the puzzle (or math string, whatever you want to call it) when it's instantiated. I was going to make a method getAnswer() in which I would instantiate the InToPost class (the class from the book) to convert the infix to postfox notation and then calculate the answer. But whilst doing this I thought: "Is using the InToPost class inside this method a form a high coupling, and would it be better to place this in a different method?" (such as a "convertPostfixToInfix" method, inside the PuzzleGenerator class) Thanks in advance.

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  • What brand of wireless router would be compatible with many broadband modems and easy to use?

    - by Junior Mayhé
    Good afternoon I'm having too many intermittent problems with my DLINK DIR 400 router: Wireless connection is lost with no reason. Perhaps the current router is incompatible with this Scientific Atlanta cable modem DPC 2100R2. Scientific Atlanta is a Cisco company, but I'm really worried about this combination DLink - Cisco. Could anyone recommend me a good wireless router for Windows Vista / Windows 7? Thank you

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  • What brand of wireless router would be compatible with many broadband modems and easy to use?

    - by Junior Mayhé
    Good afternoon I'm having too many intermittent problems with my DLINK DIR 400 router: Wireless connection is lost with no reason. Perhaps the current router is incompatible with this Scientific Atlanta cable modem DPC 2100R2. Scientific Atlanta is a Cisco company, but I'm really worried about this combination DLink - Cisco. Could anyone recommend me a good wireless router for Windows Vista / Windows 7? Thank you

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  • BizTalk 2009 - Custom Functoid Categories

    - by StuartBrierley
    I recently had cause to code a number of custom functoids to aid with some maps that I was writing. Once these were developed and deployed to C:\Program Files\Microsoft BizTalk Server 2009\Developer Tools\Mapper Extensions a quick refresh allowed them to appear in toolbox.  After dropping these on a map and configuring the appropriate inputs I tested the map to check that they worked as expected.  All but one of the functoids worked as expecetd, but the final functoid appeared not to be firing at all. I had already tested the code used in a simple test harness application, so I was confident in the code used, but I still needed to figure out what the problem might be. Debugging the map helped me on the way; for some reason the functoid in question was not shown correctly - the functoid definition was wrong. After some investigations I found that the functoid type you assign when coding a custom functoid affects more than just the category it appears in; different functoid types have different capabilities, including what they can link too.  For example, a logical functoid can not provide content for an output element, it can only say whether the element exists.  Map this via a Value Mapping functoid and the value of true or false can be seen in the output element. The functoid I was having problems with was one whare I had used the XPath functoid type, this had seemed to be a good fit as I was looking up content in a config file using xpath and I wanted it to appear the advanced area.  From the table below you can see that this functoid type is marked as "Internal Only", preventing it from being used for custom functoids.  Changing my type to String allowed the functoid to function as expected. Category Description Toolbox Group Assert Internal Use Only Advanced Conversion Converts characters to and from numerics and converts numbers from one base to another. Conversion Count Internal Use Only Advanced Cumulative Performs accumulations of the value of a field that occurs multiple times in a source document and outputs a single output. Cumulative DatabaseExtract Internal Use Only Database DatabaseLookup Internal Use Only Database DateTime Adds date, time, date and time, or add days to a specified date, in output data. Date/Time ExistenceLooping Internal Use Only Advanced Index Internal Use Only Advanced Iteration Internal Use Only Advanced Keymatch Internal Use Only Advanced Logical Controls conditional behavior of other functoids to determine whether particular output data is created. Logical Looping Internal Use Only Advanced MassCopy Internal Use Only Advanced Math Performs specific numeric calculations such as addition, multiplication, and division. Mathematical NilValue Internal Use Only Advanced Scientific Performs specific scientific calculations such as logarithmic, exponential, and trigonometric functions. Scientific Scripter Internal Use Only Advanced String Manipulates data strings by using well-known string functions such as concatenation, length, find, and trim. String TableExtractor Internal Use Only Advanced TableLooping Internal Use Only Advanced Unknown Internal Use Only Advanced ValueMapping Internal Use Only Advanced XPath Internal Use Only Advanced Links http://msdn.microsoft.com/en-us/library/microsoft.biztalk.basefunctoids.functoidcategory(BTS.20).aspx http://blog.eliasen.dk/CommentView,guid,d33b686b-b059-4381-a0e7-1c56e808f7f0.aspx

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  • TG'10 Conference Set

    Meeting of the nation's largest and most-comprehensive distributed cyberinfrastructure for open scientific research will take place August 2-5 Research - Computer Science - Cyberinfrastructure - National Science Foundation - Organizations

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  • TG'10 Conference Set

    Meeting of the nation's largest and most-comprehensive distributed cyberinfrastructure for open scientific research will take place August 2-5 Research - Computer Science - Cyberinfrastructure - National Science Foundation - Organizations

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  • Object-Oriented equivalent of LISP's progn function?

    - by Archer
    I'm currently writing a LISP parser that iterates through some AutoLISP code and does its best to make it a little easier to read (changing prefix notation to infix notation, changing setq assignments to "=" assignments, etc.) for those that aren't used to LISP code/only learned object oriented programming. While writing commands that LISP uses to add to a "library" of LISP commands, I came across the LISP command "progn". The only problem is that it looks like progn is simply executing code in a specific order and sometimes (not usually) assigning the last value to a variable. Am I incorrect in assuming that for translating progn to object-oriented understanding that I can simply forgo the progn function and print the statements that it contains? If not, what would be a good equivalent for progn in an object-oriented language?

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  • Would you use UML if it kept stakeholders from requesting changes frequently?

    - by Huperniketes
    As much as programmers hate to document their code/system and draw UML (especially, Sequencing, Activity and State machine diagrams) or other diagramming notation, would you agree to do it if it kept managers from requesting a "minor change" every couple of weeks? IOW, would you put together visual models to document the system if it helped you demonstrate to managers what the effect of changes are and why it takes so long to implement them? (Edited to help programmers understand what type of answer I'm looking for.) 2nd edit: Restating my question again, "Would you be willing to use some diagramming notation, against your better nature as a programmer, if it helped you manage change requests?" This question isn't asking if there might be something wrong with the process. It's a given that there's something wrong with the process. Would you be willing to do more work to improve it?

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  • Using dot To Access Object Attribute and Proper abstraction

    - by cobie
    I have been programming in python and java for quite a number of years and one thing i find myself doing is using the setters and getters from java in python but a number of blogs seem to think using the dot notation for access is the pythonic way. What I would like to know is if using dot to access methods does not violate abstraction principle. If for example I implement an attribute as a single object and use dot notation to access, if I wanted to change the code later so that the attribute is represented by a list of objects, that would require quite some heavy lifting which violates abstraction principle.

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  • JSLint -Tolerate inefficient subscripting?

    - by James Wiseman
    I'm reading the JSlint Options Documentation to understand each of the available options, and have come across one that I don't quite understand, and can't find any useful information regarding it elsewhere. sub - Tolerate inefficient subscripting true if subscript notation may be used for expressions better expressed in dot notation. Can anyone shed more light as to what this means? Thanks

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  • Silverlight (RIA Services) spontaneous culture changing

    - by Marc Wittke
    My RIA enabled Silverlight Application is setting the thread culture in the App constructor (this is absolutley okay since it is an intranet application and will never ever be used by someone who is not german): public App() { InitializeComponent(); Thread.CurrentThread.CurrentCulture = new CultureInfo("de-DE"); } It does what it should, the DataForms are displaying datetime values in german notation. BUT: it is spontaneously changing to en-US notation when navigating between items in the data source that is bound to the DataForm. Why?

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  • 912 stream processor available in OpenCL

    - by tugrul büyükisik
    I am thinking of assembling this system: AMD CPU (A8-3870 APU which has Radeon HD 6550D inside: 400 stream processors:xxx GFLOPS) nearly 110$ AMD Graphics card: HD 7750 (512 stream processors:819 GFLOPS peak performance) nearly 170$ Appropriate ram (1600MHz bus) Mainboard What GFLOPS level can I reach as a stable mode with using OpenCL and similar programs? Can I use all 912 stream processors at the same time? I am not trying to do a VS question. I need to know what could be better for scientific computing (%75 of the time) and gaming (%25 of the time) because I have a low budget. With "scientific calculations" I mean fluid dynamics/solid state physics simulating; with games I mean those that need openCL and PhysX.

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  • Ada and 'The Book'

    - by Phil Factor
    The long friendship between Charles Babbage and Ada Lovelace created one of the most exciting and mysterious of collaborations ever to have resulted in a technological breakthrough. The fireworks that created by the collision of two prodigious mathematical and creative talents resulted in an invention, the Analytical Engine, which went on to change society fundamentally. However, beyond that, we just don't know what the bulk of their collaborative work was about:;  it was done in strictest secrecy. Even the known outcome of their friendship, the first programmable computer, was shrouded in mystery. At the time, nobody, except close friends and family, had any idea of Ada Byron's contribution to the invention of the ‘Engine’, and how to program it. Her great insight was published in August 1843, under the initials AAL, standing for Ada Augusta Lovelace, her title then being the Countess of Lovelace. It was contained in a lengthy ‘note’ to her translation of a publication that remains the best description of Babbage's amazing Analytical Engine. The secret identity of the person behind those enigmatic initials was finally revealed by Prince de Polignac who, seventy years later, wrote to Ada's daughter to seek confirmation that her mother had, indeed, been the author of the brilliant sentences that described so accurately how Babbage's mechanical computer could be programmed with punch-cards. L.F. Menabrea's paper on the Analytical Engine first appeared in the 'Bibliotheque Universelle de Geneve' in October 1842, and Ada translated it anonymously for Taylor's 'Scientific Memoirs'. Charles Babbage was surprised that she had not written an original paper as she already knew a surprising amount about the way the machine worked. He persuaded her to at least write some explanatory notes. These notes ended up extending to four times the length of the original article and represented the first published account of how a machine could be programmed to perform any calculation. Her example of programming the Bernoulli sequence would have worked on the Analytical engine had the device’s construction been completed, and gave Ada an unassailable claim to have invented the art of programming. What was the reason for Ada's secrecy? She was the only legitimate child of Lord Byron, who was probably the best known celebrity of the age, so she was already famous. She was a senior aristocrat, with titles, a fortune in money and vast estates in the Midlands. She had political influence, and was the cousin of Lord Melbourne, who was the Prime Minister at that time. She was friendly with the young Queen Victoria. Her mathematical activities were a pastime, and not one that would be considered by others to be in keeping with her roles and responsibilities. You wouldn't dare to dream up a fictional heroine like Ada. She was dazzlingly beautiful and talented. She could speak several languages fluently, and play some musical instruments with professional skill. Contemporary accounts refer to her being 'accomplished in science, art and literature'. On top of that, she was a brilliant mathematician, a talent inherited from her mother, Annabella Milbanke. In her mother's circle of literary and scientific friends was Charles Babbage, and Ada's friendship with him dates from her teenage zest for Mathematics. She was one of the first people he'd ever met who understood what he had attempted to achieve with the 'Difference Engine', and with whom he could converse as intellectual equals. He arranged for her to have an education from the most talented academics in the country. Ada melted the heart of the cantankerous genius to the point that he became a faithful and loyal father-figure to her. She was one of the very few who could grasp the principles of the later, and very different, ‘Analytical Engine’ which was designed from the start to tackle a variety of tasks. Sadly, Ada Byron's life ended less than a decade after completing the work that assured her long-term fame, in November 1852. She was dying of cancer, her gambling habits had caused her to run up huge debts, she'd had more than one affairs, and she was being blackmailed. Her brilliant but unempathic mother was nursing her in her final illness, destroying her personal letters and records, and repaying her debts. Her husband was distraught but helpless. Charles Babbage, however, maintained his steadfast paternalistic friendship to the end. She appointed her loyal friend to be her executor. For years, she and Babbage had been working together on a secret project, known only as 'The Book'. We have a clue to what it was in a letter written by her nine years earlier, on 11th August 1843. It was a joint project by herself and Lord Lovelace, her husband, and was intended to involve Babbage's 'undivided energies'. It involved 'consulting your Engine' (it required Babbage’s computer). The letter gives no hint about the project except for the high-minded nature of its purpose, and its highly mathematical nature.  From then on, the surviving correspondence between the two gives only veiled references to 'The Book'. There isn't much, since Babbage later destroyed any letters that could have damaged her reputation within the Establishment. 'I cannot spare the book today, which I am very sorry for. At the moment I want it for constant reference, but I think you can have it tomorrow' (Oct 1844)  And 'I will send you the book directly, and you can say, when you receive it, how long you will want to keep it'. (Nov 1844)  The two of them were obviously intent on the work: She writes, four years later, 'I have an engagement for Wednesday which will prevent me from attending to your wishes about the book' (Dec 1848). This was something that they both needed to work on, but could not do in parallel: 'I will send the book on Tuesday, and it can be left with you till Friday' (11 Feb 1849). After six years work, it had been so well-handled that it was beginning to fall apart: 'Don't forget the new cover you promised for the book. The poor book is very shabby and wants one' (20 Sept 1849). So what was going on? The word 'book' was not a code-word: it was a real book, probably a 'printer's blank', plain paper, but properly bound so printers and publishers could show off how the published work might look. The hints from the correspondence are of advanced mathematics. It is obvious that the book was travelling between them, back and forth, each one working on it for less than a week before passing it back. Ada and her husband were certainly involved in gambling large sums of money on the horses, and so most biographers have concluded that the three of them were trying to calculate the mathematical odds on the horses. This theory has three large problems. Firstly, Ada's original letter proposing the project refers to its high-minded nature. Babbage was temperamentally opposed to gambling and would scarcely have given so much time to the project, even though he was devoted to Ada. Secondly, Babbage would have very soon have realized the hopelessness of trying to beat the bookies. This sort of betting never attracts his type of intellectual background. The third problem is that any work on calculating the odds on horses would not need a well-thumbed book to pass back and forth between them; they would have not had to work in series. The original project was instigated by Ada, along with her husband, William King-Noel, 1st Earl of Lovelace. Charles Babbage was invited to join the project after the couple had come up with the idea. What could William have contributed? One might assume that William was a Bertie Wooster character, addicted only to the joys of the turf, but this was far from the truth. He was a scientist, a Cambridge graduate who was later elected to be a Fellow of the Royal Society. After Eton, he went to Trinity College, Cambridge. On graduation, he entered the diplomatic service and acted as secretary under Lord Nugent, who was Lord Commissioner of the Ionian Islands. William was very friendly with Babbage too, able to discuss scientific matters on equal terms. He was a capable engineer who invented a process for bending large timbers by the application of steam heat. He delivered a paper to the Institution of Civil Engineers in 1849, and received praise from the great engineer, Isambard Kingdom Brunel. As well as being Lord Lieutenant of the County of Surrey for most of Victoria's reign, he had time for a string of scientific and engineering achievements. Whatever the project was, it is unlikely that William was a junior partner. After Ada's death, the project disappeared. Then, two years later, Babbage, through one of his occasional outbursts of temper, demonstrated that he was able to decrypt one of the most powerful of secret codes, Vigenère's autokey cipher.  All contemporary diplomatic and military messages used a variant of this cipher. Babbage had made three important discoveries, namely, the mathematical law of this cipher, the principle of the key periodicity, and the technique of the symmetry of position. The technique is now known as the Kasiski examination, also called the Kasiski test, but Babbage got there first. At one time, he listed amongst his future projects, the writing of a book 'The Philosophy of Decyphering', but it never came to anything. This discovery was going to change the course of history, since it was used to decipher the Russians’ military dispatches in the Crimean war. Babbage himself played a role during the Crimean War as a cryptographical adviser to his friend, Rear-Admiral Sir Francis Beaufort of the Admiralty. This is as much as we can be certain about in trying to make sense of the bulk of the time that Charles Babbage and Ada Lovelace worked together. Nine years of intensive work, involving the 'Engine' and a great deal of mathematics and research seems to have been lost: or has it? I've argued in the past http://www.simple-talk.com/community/blogs/philfactor/archive/2008/06/13/59614.aspx that the cracking of the Vigenère autokey cipher, was a fundamental motive behind the British Government's support and funding of the 'Difference Engine'. The Duke of Wellington, whose understanding of the military significance of being able to read enemy dispatches, was the most steadfast advocate of the project. If the three friends were actually doing the work of cracking codes by mathematical techniques that used the techniques of key periodicity, and symmetry of position (the use of a book being passed quickly to and fro is very suggestive), intending to then use the 'Engine' to do the routine cracking of each dispatch, then this is a rather different story. The project was Ada and William's idea. (William had served in the diplomatic service and would be familiar with the use of codes). This makes Ada Lovelace the initiator of a project which, by giving both Britain, and probably the USA, a diplomatic and military advantage in the second part of the Nineteenth century, changed world history. Ada would never have wanted any credit for cracking the cipher, and developing the method that rendered all contemporary military and diplomatic ciphering techniques nugatory; quite the reverse. And it is clear from the gaps in the record of the letters between the collaborators that the evidence was destroyed, probably on her request by her irascible but intensely honorable executor, Charles Babbage. Charles Babbage toyed with the idea of going public, but the Crimean war put an end to that. The British Government had a valuable secret, and intended to keep it that way. Ada and Charles had quite often discussed possible moneymaking projects that would fund the development of the Analytic Engine, the first programmable computer, but their secret work was never in the running as a potential cash cow. I suspect that the British Government was, even then, working on the concealment of a discovery whose value to the nation depended on it remaining so. The success of code-breaking in the Crimean war, and the American Civil war, led to the British and Americans  subsequently giving much more weight and funding to the science of decryption. Paradoxically, this makes Ada's contribution even closer to the creation of Colossus, the first digital computer, at Bletchley Park, specifically to crack the Nazi’s secret codes.

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