https://community.wolfram.com RSS Feed for Wolfram Community showing questions from all groups sorted by most likes. https://community.wolfram.com/groups/-/m/t/181759 I was wondering, it would be interesting to try to use the community as a way to request new functions that could be incorporated into new versions of Wolfram Language, in a colaborative way. Sometimes users simply don't have the whole/deeper system view, to understand that the requested function is or too specific, too broad or already implemented, but I believe that another times we can have a nice insights, that Wolfram Research people haven't yet, or that do not have received much attention  yet.  To the idea is: [b]Post your's requested Function as a answer to this question, and let's upvotes show the more interesting ones![/b] Some rules 1- One Post per function (or class of function), you can have more than one request. 2- Exemplify your function use. Rodrigo Murta 2014-01-08T09:14:19Z https://community.wolfram.com/groups/-/m/t/1321057 This is a cautionary tale for those who choose Mathematica as the main tool for their work. It is now clear to me that Wolfram has simply abandoned the [Graphs and Networks](http://reference.wolfram.com/language/guide/GraphsAndNetworks.html) functionality area and I am left high and dry. I have no recourse because Mathematica is closed source so there is only so much a user can do to fix or work around problems. Reporting bugs in this particular area has now clearly proven to be useless. Most simply do not get fixed, no matter how serious they are, or how great a hindrance they are to practical use. No new functionality has been added since version 10.0. My colleagues who use other tools (mostly Python and R packages) are more productive at this point, but I have a handicap with those systems because I made the mistake of investing most of my time into Mathematica, and stayed optimistic about it even in the face of the most obvious warning signs. I am writing this post because those people who have not heavily invested in Mathematica, and in particular this functionality area of Mathematica, are not in a position to see this and may fall in the same trap I did. What if the same thing happens to the functionality area that is critical to *your* work? Wolfram Research, of course, will not tell you that they gave up on `Graph`. Thus, after my experience, I think I owe it to the community to warn you about the situation. ---- Some might ask me what specifically is wrong. I have made many posts on this forum about `Graph`-bugs (you only have to search), and I reported many more to WRI. There is always a last straw—it would be pointless to show it. Those who know me will know that I am not writing this admittedly emotional post out of ill will towards WRI. I have betted on Mathematica more than most, and have been advocating for it throughout the years. I even have a network analysis package with ~250 functions. If I am forced to abandon Mathematica for this type of work, then the countless hours that went into this package will all have been in vain. I admit that I am writing this public post partly out of desperation to try to get WRI to either fix the many serious `Graph`-problems, or otherwise publicly state that `Graph` is now abandoned so those of us who have been using it can stop wasting our time. Szabolcs Horvát 2018-04-16T09:54:42Z https://community.wolfram.com/groups/-/m/t/2267653 *MODERATORS' NOTE: We will be displaying the collage of people's images at the top of this discussion. Dear all, please, do post the images of Wolfram things dear to your memories here :-) Thank you, Daniel Carvalho, for a delightful question!* ![enter image description here][1] ---------- Today installing Mathematica 12.3 I notes that there are previous versions installed too in my Linux box: daniel@home:/opt/Wolfram/Mathematica$ ls -l total 28 drwxr-xr-x 7 root root 4096 nov 20 2014 10.0 drwxr-xr-x 7 root root 4096 ago 14 2016 11.0 drwxr-xr-x 7 root root 4096 abr 26 2017 11.1 drwxr-xr-x 7 root root 4096 jun 26 2020 12.1 drwxr-xr-x 7 root root 4096 jan 12 23:20 12.2 drwxr-xr-x 3 root root 4096 mai 13 13:23 12.3 drwxr-xr-x 7 root root 4096 ago 19 2013 9.0.1 It is interesting to see that the older version is around 9 in 2013, and the years of installation for the other releases, according my folders. In fact my first version of Mathematica was 4.0 (1999), for calculus classes in college. In Computer Engineering that time we had 5 semesters of calculus classes, and just the last one we went to the lab to make some more interesting projects applying the theory to practical experiments. The basic calculus classes usually ware just whiteboard, pen and paper, book and exercises. A very traditional engineering college. It was interesting getting the last exercises from lists, the most complex cases, and have it solved immediately!! I can recall that version 6.0 was the most interesting for me, I have used it at master degree. Since version 6.0 I have been publishing lots of [Demonstrations][2] with the [Manipulate][3] function, it is really fun! It got my playing video game timing! :-) In my parents house I found this boxes with my old college stuff: ![enter image description here][4] I went to the Wolfram Summer School in [2007][5] while back in college for the Master in Electrical Engineering, and latter again in [2011][6] for a new research about [NKS][7] computational principles. Latter on I get certified, [Wolfram Certified Instructor][8] Since 2013 I have been organizing the Wofram conference in Brazil with [Mackenzie University][9] team and other friends, by my installations dates, I have used 9.0.1 at the first conference here. In 2021 and 2020 the conf is virtual for safety (remote): [https://www.wolfram.com/events/virtual-conference-br/2020/][10] And now I am very excited with 12.3!! The Mathematica versions history is available at: [https://www.wolfram.com/mathematica/quick-revision-history.html][11] What was your first Mathematica version?? [at0]: https://community.wolfram.com/web/danielscarvalho [Original]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Eew570TWkBEyea5.jpeg&userId=1518234 [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=colmv.jpeg&userId=11733 [2]: https://demonstrations.wolfram.com/author.html?author=Daniel%20de%20Souza%20Carvalho [3]: https://reference.wolfram.com/language/ref/Manipulate.html [4]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Eew570TWkBEyea5.jpeg&userId=20103 [5]: https://education.wolfram.com/summer-school/alumni/2007/carvalho/ [6]: https://education.wolfram.com/summer-school/alumni/2011/carvalho/ [7]: https://www.wolframscience.com/ [8]: https://www.wolfram.com/wolfram-u/instructors/carvalho.html [9]: https://www.mackenzie.br/ [10]: https://www.wolfram.com/events/virtual-conference-br/2020/ [11]: https://www.wolfram.com/mathematica/quick-revision-history.html Daniel Carvalho 2021-05-13T16:49:32Z https://community.wolfram.com/groups/-/m/t/2253852 I realize that I am possibly the only Mathematica user to suffer from existential angst for the product, but still, its worth pausing to ask the question, what is Mathematica for? Meaning, what is its purpose? But for those of you pragmatists tempted to roll your eyes and just get on with using it, let me motivate the question with a chart: ![enter image description here][1] You don't need a model to figure out the long term trend in that time series. And someone, somewhere, in WR needs to be asking the question I am posing in this post, if they are seriously hoping to check that trend and reverse it. Now, let's be fair here. Firstly this is not just a Mathematica issue. For example, here's the comparable chart for Matlab: ![enter image description here][2] So I am not "picking on" Mathematica. Its a general problem for mathematical programming languages. Or perhaps I should say, more accurately, its a challenge for proprietary mathematical programming languages: ![enter image description here][3] Now this "analysis" is of course over-simplistic. It could be, for example, that the downward trend in Mathematica interest is a reflection of a decision by WR to increase prices over time, to maximize profits, i.e. it could conceivably be a *good* thing. But I rather suspect otherwise and instead tend to believe that Mathematica is losing influence and relevance, regardless of whatever I may think of the product. Another response might be: "Of course we are losing market share to license-free, direct competitor products. What's your point?". To which, I suppose, the answer might be: "Are you quite sure that is inevitable? Are there not examples of for-profit products that are so good they are able to maintain market share in the face of cost-free alternatives?". The answer to that question is, of course, yes. But in order to maintain your competitive position you have to be crystal clear in your understanding of what the value proposition is, and why customers will (continue to) pay for your product. Which brings me to the subject of this post: what is Mathematica for? Because unless can answer that question, you can't answer the earlier one. Now I have a theory that the generally held view in WR is that Mathematica is for any kind of programming task you can conceive of. It's a general purpose tool, limited in its capabilities only by your imagination. And at this point we could now queue up a 15 minute informercial featuring examples of applications from Astronomy to Zoology. But just because you *can* do something in Mathematica doesn't mean you should: there are often better alternatives. Mathematica has developed into something like a Swiss Army knife, a general purpose tool you can use for almost any purpose. But, often times what you need is a tool with a specific purpose, like a screwdriver, which will make it much easier to complete the task you have in mind. Let's take a simple example: spreadsheets. I have seen several attempts to get Mathematica to do the kind of thing that Excel can do effortlessly. And the question I always end up asking myself is: "why on God's green earth would anyone in their right mind try to use Mathematica for a task like that?". What is trivial to accomplish in a few seconds or minutes in Excel, typically takes hours of jumping through hoops with Mathematica to achieve a result that is almost always inferior. It's like trying to navigate a freeway in a spaceship, rather than a motor car. Sure, you can do it, buy why?? Another no-no is trying to develop stand-alone software applications in Mathematica. It's extremely hard to do - typically much tougher then using a language designed for that purpose. On the other hand, there are some things that Mathematica excels at, such as: - Mathematics/symbolic logic/symbolic manipulation: superb. Best of breed. - Graphics (including animation) ditto - Documentation. Also superb. Now as good at Matlab, possibly even superior. After that, you could pick a bunch of different application areas in which Mathematica is great. But best of breed? I dont know. Let's take an area I know a little about: time series analysis. prior to 2010, Mathematica was truly awful at handling time series. Basically it didn't. Gradually, over subsequent releases, Mathematica has made enormous strides in this area to the point where it is truly magnificent. For which someone at WL deserves (and I hope has received), several promotions. But despite this, Mathematica is still not best of breed in this area. Why? Because, unaccountably, it is still missing several vital elements of functionality such as Granger causality/ Cointegration and its implementation of important functionality like the Kalman Filter is horribly unintuitive. This shows two things: (i) it is possible for WR to make Mathematica outstanding in almost any area it chooses to. it's just a question of focus. And (ii) to become best of breed, you need to finish the job! By which I mean, provide something close to 99% of the functionality that a professional practitioner in that area would expect to have available. if it chose to, WR could accomplish that in the time series area in a single release, I would guess. The problem, I am suggesting, is that in trying to make Mathematica a product that is "all things to all men", it fails to achieve the status of being indispensable to practitioners in a more limited subset of subject areas. Ok let's go with this conjecture for a moment. Let's wave a magic wand and imagine that we can change Stephen Wolfram's vision about his flagship product, which he has sweated blood over for the last 20-30 years (in other words, this is never going to happen - but its still fun to play the game). What core capabilities would you have WR focus on with the aim of making Mathematica an indispensable product in that area? Here are my choices: (i) Time series & econometrics. Mathematica is so close: just finish the job - it's a no-brainer! (ii) Machine learning. This also means making sure that the GPU capability works as it should, first time and every time. Mathematica still has a way to go here and its a huge area. But I'm sure WR could do it. (iii). Meta-Programming. This one is a BIG stretch. But it just happens that WL may have a huge potential competitive advantage, because the language is itself *computational*. in other words, the building blocks of the language can themselves be manipulated, which is exactly what you need for meta-programming. Try doing that in Python! On this subject I would say that the starting point would be to create WL functionality capable of generating a single line of WL code that is sufficiently complex and interesting to win the Wolfram One-Liner competition. I realize that's a huge challenge and its not just about the difficulty of navigating the terrain of the Wolfram language. It also involves thinking about what "complex" and "interesting" mean, in this context. Think of this as a Turing test, for Metaprogramming capability. Once it's passed, it would open up a floodgate of possibilities, both for WL aficionados but also, critically, for those who don't program in WL, or indeed in any language at all. For reference, check out whats going on in the world of "no -code" application environments. [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=GoogleTrendsMathematica.png&userId=773999 [2]: https://community.wolfram.com//c/portal/getImageAttachment?filename=GoogleTrendsMatlab.png&userId=773999 [3]: https://community.wolfram.com//c/portal/getImageAttachment?filename=GoogletrendsPython.png&userId=773999 Jonathan Kinlay 2021-04-26T16:09:01Z https://community.wolfram.com/groups/-/m/t/774416 I originally posted this on Stack Exchange, where it was suggested it would more appropriately be posted here. The only "real-world" application that meets the specified criteria offered so far (twice) has been Wolfram Alpha (I am not entirely sure that it meets the second criterion - would you choose to develop WA in WL, if you didn't have a bunch of WL experts and a WL development platform at your disposal?). In any event, I am interested in hearing about other real-life applications.... I have a theory, which I am in the process of writing about in a blog post, that other than in applications in mathematics (symbolic logic), Mathematica's primary usefulness is in encouraging a kind of intellectual dilettantism. (Of course, one man's dilettantism is another man's New Kind of Science: i.e. the speculative endeavors of a fertile, creative intellect might readily be mistaken for actual (scientific) achievement by less agile minds.) I don't want this conjecture to be true: I'm as much a buyer of the hype around Mathematica as the next man. But I have noticed that, in practice, Mathematica somehow fails to live up to its apparently unlimited potential for encapsulating creative thought-product across an almost unlimited span of human intellectual endeavor. In my own work in finance, for instance, it has generally proved much less useful than other products such as Matlab. And, in general, when I look at the examples cited by Wolfram in its "customer stories", my reaction to many of them is: "Sure, you can use Mathematica to do that. But why would you, when there are much better alternatives available?". To take one such customer story from the field of 3D CAD, I don't understand why anyone would *prefer* to use Mathematica for such a task, rather than a specialist product like Solidworks. I am aware of applications where the use of Mathematica is fully justified. In my own work, I have used Mathematica to price complex derivatives products, a field in which it excels. Likewise, I am somewhat familiar with Phil Zecker's work at EQA Partners, where he produced an outstanding risk management solution using Mathematica. In both these cases, however, there is no standard, specialized alternative offering in the field of risk management, as there are, for example, in engineering, CAD, app design, or music. In these areas, it seems to me, Mathematica is like a Swiss Army Knife: sure you can use it to dabble in almost anything; but I have screwdrivers, knives and corkscrews that do a better job for their specific purpose. In any event I am looking for counter-examples of real-world applications to refute my hypothesis about Mathematica. By "real-world" I mean specifically applications in which: (i) money changed hands (e.g. a commercial product was sold, or consulting fee earned) ; and (ii) an alternative solution was considered and Mathematica preferred for specific reasons ("it was the only software we could afford or that was available to tackle the job", is not a valid reason to qualify the application as real-world, according to this definition) Jonathan Kinlay 2016-01-17T16:05:55Z https://community.wolfram.com/groups/-/m/t/288532 I am doing some project planning that could use the CDF Player and CDF technology as a means of distributing a mathematical model to reviewers. However, I've noticed that the documentation for 9 is really for 8. There have been some indications that 10 is coming out with no changes to the documentation since version 8. There is no File | New | CDF (Free or Pro) is 9. The latest CDFs in CDF-Examples are from 2012. This raises a red flag that CDFs are no longer mainstream. Ideally we would like to use a technology that is supported and will stay current with Windows and Apple OS versions. I see that there is a CDF Export and Preview under the File menu. Some of the questions I will be asked by management are: 1. Is CDF considered a legacy technology? If not, will it be available in 10 and future versions - is there a roadmap that can be referenced? 2. If CDF is considered legacy, when do support options expire? 3. Are there any replacements planned from Wolfram that are functionally equivalent to CDFs? If so what are they? 4. What are runtime licensing considerations that should be honored if we use C and C++ as a front-end? CDFs offer an attractive solution - I love what I am seeing in the CDF-Examples - but before committing to CDFs we need to know that this technology is on-going and will stay current with Mathematica and operating systems. Doug Kimzey 2014-07-06T14:44:27Z https://community.wolfram.com/groups/-/m/t/1096129 Can somebody give a succinct comparison of the features of the various products: Mathematica, Mathematica Online, Wolfram|One, Wolfram Development Platform, Wolfram Cloud, Wolfram Data Drop. I find differentiating so many similar products — especially those manifestly cloud-based — rather confusing. Murray Eisenberg 2017-05-16T18:35:44Z https://community.wolfram.com/groups/-/m/t/2103748 My 14-year-old son is medically complex, including being a quadriplegic. He currently uses software (Grid 3) to communicate ideas and an eye tracker (Tobii) with software that allows him to "type" using his eyes. I am looking for tools that will allow him to work out a math problem through its various steps (since he cannot hold a pencil and write on paper to show his work), and I thought Mathematica might be a tool that could help. Has anybody successfully used Mathematica using mouse movements alone and not typing anything on the keyboard? Thanks. Myles Dear 2020-10-28T18:37:55Z https://community.wolfram.com/groups/-/m/t/291822 Is Wolfram Workbench going to be updated to work well with Mathematica 10 and the new syntaxes and operators introduced (`<| ... |>`, `@*` and `/*`)? Szabolcs Horvát 2014-07-11T22:29:14Z https://community.wolfram.com/groups/-/m/t/148287 I am an artist, drawing and working with 3d. Since long time, I am missing a method to form realistic folds and wrinkles into virtual sheets of paper, metal or cloth. I found some attempts within 3d-programs, but I never saw something that was not very limited or looked like rubber. Because it is so easy at reality, but so difficult at the computer, I think there is just little mathematical base.First of all: Could anybody tell me, what field of mathematics this is? [img=width: 800px; height: 1132px; ]/c/portal/getImageAttachment?filename=Folds-01.jpg&userId=145842[/img] [img=width: 800px; height: 1132px; ]/c/portal/getImageAttachment?filename=Folds-02.jpg&userId=145842[/img] Dietmar Klein 2013-11-03T23:03:23Z https://community.wolfram.com/groups/-/m/t/922544 Dear all, my data consist of a list of lists of points in 3D. After running the code ClearAll["Global`*"] SetDirectory[NotebookDirectory[]]; sliceData = << "SliceData.txt"; Graphics3D[Line /@ sliceData, Boxed -> True, Axes -> True] one gets: ![enter image description here][1] Clearly the data describe a 3D object (as "wire frame"). **QUESTION:** *How can those data be converted into a single 3D Mathematica object (graphics, mesh, ...)? Is there an already implemented way (a routine) I am missing?* ---------- NOTE on DATA: ------------- The data stem from our radiotherapy treatment planning system. There we are working with contours which are drawn on any single CT slice. Organs at risk and target volumes are defined by those contours. One special contour is the "BODY contour"; this is what is shown in my example data. Dose will be calculated only inside this BODY contour, therefore e.g. the volume around the ears and nose appears to be exaggerated (for being on the safe side). Those treatment plans can be exported as DICOM files and nicely imported in Mathematica. When high energy radiation is applied to a body it turns out that the dose next to the skin is highly diminished; this is due to the buildup effect of the dose. When full dose at the skin is wanted, one has to anticipate this buildup effect, and this can be realized by putting a "flab" onto the skin: A flab is a layer made of some tissue equivalent material. Optimal flabs can have quite irregular shapes. I recently learned at a conference that there is the possibility to 3D print those individual flabs - if one can provide the data ... So - probably to everybody's disappointment - I do not want to print any BODY contour, but I imagined a BODY contour might serve here as kind of a "honey pot". Best regards and many thanks! -- Henrik [1]: http://community.wolfram.com//c/portal/getImageAttachment?filename=sliceImg.png&userId=32203 Henrik Schachner 2016-09-11T20:40:44Z https://community.wolfram.com/groups/-/m/t/71162 As most followers of online Mathematica fora will have noticed, one of the all-time hottest desired features of Mathematica is the Multiple Undo feature. While working in a notebook it is possible to irrecoverably lose all of your work with just a click and a few key presses. In a discussion I had with John Fultz during the 2011 WTC, John sketched the difficulty of returning to a previous executional state. However, while going back in state would be a very nice feature to have, this is much, much more than most users desire. I guess most of us would be very pleased if we could undo *manual* changes to *input cells only* for a reasonable number of steps, say 10. I know of many people who would be willing to give up all the goodies that v10 may bring if they only could get a simple text-based multiple undo. The question is whether WRI is sufficiently aware of the wishes of its user community in this context and whether the apparent overstatement of the Undo functionality in terms of execution state may stand in the way of the implementation of a much simpler version that would satisfy the basic needs? Sjoerd de Vries 2013-07-24T13:49:04Z https://community.wolfram.com/groups/-/m/t/942720 As many of you already know, the breaking news today was [Bob Dylan and his Nobel Prize in Literature][1]. You can also take a look at [New York Times announcement][2]. Somehow, maybe because Bob conquered a global ocean of hearts and changed the mind of modern society, this sounds very exciting and calls for a celebration. So what can we do to celebrate a computational way? I challenge you, ladies and gentlemen, to come up with an idea, piece of code, visualization and more to pay our tribute to one of the greatest voices of our generation. Here is an example. Bob Dylan Infinite Universe ------------------ Bob interacted with our culture so much his impact can hardly be measured. But we can take a look at Wikipedia data of his page connectivity to other pages. Even going just 2 levels deep and limiting 100 inter-page links per page we get the whole Universe of Bob Dylan. You can get lost by rolling over the nodes of the network. Infinitely. Well, almost. Watch animation and see if you can recognize some names. **Please also look through the comments way down to observe more of the visible Universe ;-)** linksTO=WikipediaData["Bob Dylan","BacklinksRules","MaxLevelItems"->100,"MaxLevel"->2]; linksFROM=WikipediaData["Bob Dylan","LinksRules","MaxLevelItems"->100,"MaxLevel"->2]; Graph[Union[Join[linksTO, linksFROM]], VertexLabels -> Placed["Name", Tooltip], VertexSize -> Scaled[.01], DirectedEdges -> False, Background -> Black, EdgeStyle -> Directive[White, Opacity[.5]], VertexStyle -> Directive[Red, Opacity[.8]]] ![enter image description here][3] [1]: https://www.nobelprize.org/nobel_prizes/literature/laureates/2016/ [2]: http://www.nytimes.com/2016/10/14/arts/music/bob-dylan-nobel-prize-literature.html [3]: http://community.wolfram.com//c/portal/getImageAttachment?filename=456rtrt56564564trhstea5467.gif&userId=11733 Vitaliy Kaurov 2016-10-13T17:11:04Z https://community.wolfram.com/groups/-/m/t/291612 Since about Version 6 it has taken longer and longer to start up Mathematica. In Version 10 on my HP Pavilion HPE Series it takes a little over a minute. Is this common experience? Is there some way to decrease this time? Does it have any thing to do with virus checking? I guess that one possible solution is to just leave the Mathematica FrontEnd open all the time, say by keeping the Documentation Center open but minimized. David J M Park Jr 2014-07-11T19:45:42Z https://community.wolfram.com/groups/-/m/t/2380163 I recently noticed that Mathematica uses MxNet as the backend for neural networks. It seems to have been integrated in 2015. The blog post listing the rationale is [here](https://www.oreilly.com/content/apache-mxnet-in-the-wolfram-language/). MxNet seems to have not gained the momentum to become popular, you can see the [trends](https://paperswithcode.com/trends) from "papers with code". Lack of popularity means framework may be slow to develop. For instance, this [question](https://mathematica.stackexchange.com/questions/256323/neural-network-automatic-differentiation-autograd) about using neural networks to fit ODEs from Joshua Schrier. It requires underlying framework to support higher order gradients. There's an [issue](https://github.com/apache/incubator-mxnet/issues/10002) to add support in MxNET but progress has stalled. Meanwhile PyTorch/TensorFlow/JAX support this feature. Yaroslav Bulatov 2021-10-06T00:49:07Z https://community.wolfram.com/groups/-/m/t/2118125 Are there any benchmarks yet for Mathematica 12.1 on the new (13") M1 MacBook Air or (13") M1 MacBook Pro? Murray Eisenberg 2020-11-18T20:19:23Z https://community.wolfram.com/groups/-/m/t/289856 For me, it's strange the column redundant implementation of Dataset, that do not allow a memory efficient representation of a simpler tabular data format (as SQL data). As each column name is in each line, is't not memory efficient. See this test: compare[lines_,columns_]:=Module[{l1,l2}, l1=RandomInteger[1000000,{lines,columns}]; l2=AssociationThread["Columns"<>ToString@#&/@Range[columns]-> #]&/@l1; ByteCount[l2]/ByteCount@Dataset[l1]//N ] compare[100000,4] > 19.9959 I get approximately 20x more memory for it!.. I know that Dataset is a cool tool for Hierarchical data structure. But I believe that 95% of data problems are still rectangular (all SQL queries are), and the current format of Dataset is very memory inefficient for that. Maybe Dataset could have a option TabularData-> True, so: ds=Dataset[<|"col1" -> {1, 2, 3, 4}, "col2" -> {"a", "b", "c", "d"}|>, TabularData-> True] Here we can check that this structure do not need more memory: compare[lines_,columns_]:=Module[{l1,l2}, l1=RandomInteger[1000000,{lines,columns}]; l2=Thread["Columns"<>ToString@#&/@Range[columns]-> Transpose@l1]; ByteCount[l2]/ByteCount@Dataset[l1]//N ] compare[100000,4] > 1.0007 There are some Wolfram plans better handler Tabular Data in Dataset? Rodrigo Murta 2014-07-10T03:48:54Z https://community.wolfram.com/groups/-/m/t/567757 Here I will show a way to do some analysis of GPS data using new functionality present in the Wolfram Language. I just moved to Lyon (France), where they organised a mountainbike tour last week ([Lyon Free VTT][1]). I opted for the 'expert' trail of roughly 60 km with 1000+ meters ascend. I recorded my trip using the Garmin GPSmap 62s and I'm wearing a heart rate sensor from Garmin as well. We start by setting the current directory to the notebookdirectoy, and look for the GPX file of the day of the event: SetDirectory[NotebookDirectory[]]; fn = FileNames["*2015-09-13*.gpx"][[1]] "Track_2015-09-13 121636.gpx" So we found the file. The GPX file is an XML formatted file. So we can read the data easily: data = Import[fn, "XML"]; The data is stored in "track points" which are abbreviated as `trkpt`. We can find the parts of the track by using `Cases`. FirstCase[data, XMLElement["trkpt", ___], Missing[], \[Infinity]] which looks like: XMLElement[trkpt,{lat->45.7242092583,lon->4.8268832266}, {XMLElement[ele,{},{173.17}], XMLElement[time,{},{2015-09-13T06:09:03Z}], XMLElement[extensions,{},{ XMLElement[{http://www.garmin.com/xmlschemas/TrackPointExtension/v1,TrackPointExtension},{},{ XMLElement[{http://www.garmin.com/xmlschemas/TrackPointExtension/v1,hr},{},{108}]} ]} ]} ] Wow! Looks quite complicated, but the important thing is that it always starts with the Latitude and Longitude coordinates as `attributes -> values`, and then followed by some more data (in this case the time, elevation, and heart rate). So lets get all the track points: data = Cases[data, XMLElement["trkpt", {"lat" -> lat_, "lon" -> lon_}, other_] :> {ToExpression /@ {lat, lon}, other}, \[Infinity]] Note that I immediately detect the `latitude`, `longitude` and the `other` data and put them as a replacement rule right in `Cases`. I started recording when I left my house to go to the Start, and I also continued recording after I cycled back from the finish to my house. So we remove this data: data = Drop[Drop[data, 246], -128]; The trail is now stored as the first element of each element of data: trail = GeoPosition /@ data[[All, 1]]; We can now easily visualise this using the new GeoGraphics function (V10 and up): GeoGraphics[{Thick, Line[trail]}, ImageSize -> 400] Giving: ![enter image description here][2] That looks pretty good! Now let's retrieve the time, elevation and heart rate from the data. We overwrite data, because we already extracted the latitude and longitude from it: data = data[[All,2]]; First, let's try the time, we use the new `FirstCase` command (V10) as we only expect one time per track point entry. We make a pure function and map that over all the data: absolutetime = time = Map[ FirstCase[#,XMLElement["time",{},{time_}]:>AbsoluteTime[time]+$TimeZone*3600,Missing[],\[Infinity]]& , data ] time -= First[time] Note that I also add some seconds so that I have the time in my own timezone (the default is in Zulu (universal) time). In case the time is somehow not recorded it will returning `Missing[]`. I will also save a variable which is the time starting when I start called `time` (second line). We can do something similar for the elevation: elevation=Map[FirstCase[#,XMLElement["ele",{},{ele_}]:>ToExpression[ele],Missing[],\[Infinity]]&,data] and for the heart rate: hr=Map[FirstCase[#,XMLElement[{"http://www.garmin.com/xmlschemas/TrackPointExtension/v1","hr"},{},{hr_}]:>ToExpression[hr],Missing[],\[Infinity]]&,data]; Now that we have all the data, let's explore a little bit further. Let's first compute the distance travelled: distances=BlockMap[GeoDistance@@#&,trail,2,1]; distances=Prepend[QuantityMagnitude[distances,"Meters"],0.0]; distance=Accumulate[distances]; Here I used the new BlockMap function (V10.2) to compute the distance between each pair of points. (2 to denote pairs, and 1 to have overlapping pairs). I convert the results to just number (without units), otherwise the `Accumulate` is very slow (why is this slow Wolfram?). Lastly I keep track of the accumulated distance using the command `Accumulate`. Now we can plot this as a function of time: DateListPlot[{absolutetime,distance}\[Transpose],FrameLabel->"Meters",FrameStyle->12,ImageSize->400] giving: ![enter image description here][3] The total distance travelled is: Last[distance] 57106. This answer is in meters because I took the magnitude in "Meters". We can convert it to miles quite easily: UnitConvert[Quantity[%, "Meters"], "Miles"] 35.484mi About 35.5 miles. Let's calculate the speed: speed=Differences[distance]/Differences[time]; speed=Join[{speed[[1]]},MovingAverage[speed,2],{speed[[-1]]}]; The first order difference will give me the speed, I'm doing a moving average so that I have the average speed at an instant, I append and prepend the first and last speed, respectively, such as to have the length of `speed` and the length of `time` to be the same. Now we can plot the speed (which is in meter/second, so I multiply by 3.6 to get km/h): DateListPlot[Transpose[{absolutetime,3.6speed}],FrameLabel->"Kilometer/Hour",FrameStyle->12,ImageSize->1000,AspectRatio->1/5,PlotRange->All] ![enter image description here][4] My speed varies a lot as you can see. This is partly because this is an urban trail with climbs and descends, but also sharp corners, and up and down-going stairs. But also because of some GPS errors you have some fluctuations. This is apparent in the above plot, I'm quite fast, but not 80 km/h (50 miles/hour) fast!! So let's smooth the data over a few points: slen=3; smoothspeed=Join[Accumulate[speed[[;;slen]]]/Range[slen],MovingAverage[speed,2slen+1],Reverse[Accumulate[Reverse[speed[[-slen;;]]]]/Range[slen]]]; Which looks more realistic: DateListPlot[Transpose[{absolutetime,3.6smoothspeed}],FrameLabel->"Kilometer/Hour",FrameStyle->12,ImageSize->1000,AspectRatio->1/5,PlotRange->All] ![enter image description here][5] You can clearly see that I had a flat tire around 10:15 that took me 7-8 minutes to repair... Let's calculate the average speed (up to some time t): avgspeeds=Prepend[Rest[distance]/Rest[time],0]; And showing: DateListPlot[Transpose[{absolutetime,3.6avgspeeds}],FrameLabel->"Kilometer/Hour",FrameStyle->12,ImageSize->1000,AspectRatio->1/5,PlotRange->All] ![enter image description here][6] So I ended with a speed of `3.6 Last[avgspeeds] = 14.5 km/h` which is not too bad considering it includes also a flat tire. Plotting the elevation is also quite easy now: DateListPlot[Transpose[{absolutetime, elevation}], FrameLabel -> "Meters", FrameStyle -> 12, ImageSize -> 1000, AspectRatio -> 1/5, PlotRange -> All] ![enter image description here][7] There were some very steep hills in this track, and pieces where I had to change to my lowest gear to climb them. Also plotting the heart rate is quite easy: DateListPlot[Transpose[{absolutetime,hr}],FrameLabel->"BPM",FrameStyle->12,ImageSize->1000,AspectRatio->1/5,PlotRange->All] ![enter image description here][8] Let's compute the total number of heart beats and the average heart rate: hb=Interpolation[DeleteMissing[{time,hr/60.0}\[Transpose],1,2],InterpolationOrder->1]; hb=Round[Integrate[hb[t],{t,Min[time],Max[time]}]] avghr=60hb/(Max[time]-Min[time]) 38443 (* beats *) 162.8 (* average beats / minute *) That is quite high for my age (28 years)! Let's compute the elevation gain: elevationgain = Total[Select[Differences[elevation], Positive]] 1193.05 (* meters *) That explains partly the low speeds and the high heart rates! I've climbed almost 1200 meters. QuantityMagnitude[Quantity[elevationgain,"Meters"],"Stories"] or about 400-500 stories!! (depending on your metric of a storey) Let's make a visual plot where the climbs are by creating a map colored by the height: colordata = Rescale[elevation]; color = Blend[{{0, Darker@Green}, {0.5, Yellow}, {1, Red}}, #] & /@ colordata; GeoGraphics[{AbsoluteThickness[8], JoinForm["Round"], Line[trail, VertexColors -> color]}, ImageSize -> 400] ![enter image description here][9] Green means low, and red means high altitude. Using the same colors we can create also the accompanying plot: DateListPlot[Transpose[{absolutetime,elevation}],FrameLabel->"Meters",FrameStyle->12,ImageSize->1000,AspectRatio->1/5,PlotRange->All,ColorFunction->(Blend[{{0,Darker@Green},{0.5,Yellow},{1,Red}},#2]&),PlotStyle->Directive[AbsoluteThickness[5],JoinForm["Round"]]] ![enter image description here][10] Or the same but instead colored by the speed: colordata=Rescale[smoothspeed]; cf=Blend[{{0.2,Red},{0.45,Yellow},{0.8,Darker@Green}},#]&; color=cf/@colordata; g1=GeoGraphics[{AbsoluteThickness[8],JoinForm["Round"],Line[trail,VertexColors->color]},ImageSize->400] DateListPlot[Transpose[{absolutetime,3.6smoothspeed}],FrameLabel->"km/h",FrameStyle->12,ImageSize->1000,AspectRatio->1/5,PlotRange->All,ColorFunction->(cf[#2]&),PlotStyle->Directive[AbsoluteThickness[5],JoinForm["Round"]]] ![enter image description here][11] ![enter image description here][12] In the corners and in the climbs it is slow (red), while for the flat, down, and straight pieces it is fast (green). It looks like there is way more green, then red on the map, while for the bottom plot it is roughly equal, this is because for a low speed you travel only a little so just a bit of red on the map. While for high speed you travel more distance so it looks more green... This is part I, below I will post a second part of the analysis. With some nice general functionality. PS. Also have a look at the 2009 post at the wolfram blog when GeoGraphics (and other functions) were not introduced yet. [Wolfram Blog about GPS][13] [1]: http://www.lyonfreevtt.com [2]: /c/portal/getImageAttachment?filename=1_map.png&userId=73716 [3]: /c/portal/getImageAttachment?filename=2_distance.png&userId=73716 [4]: /c/portal/getImageAttachment?filename=3_speed.png&userId=73716 [5]: /c/portal/getImageAttachment?filename=3.5_smoothspeed.png&userId=73716 [6]: /c/portal/getImageAttachment?filename=4_avgspeed.png&userId=73716 [7]: /c/portal/getImageAttachment?filename=5_elevation.png&userId=73716 [8]: /c/portal/getImageAttachment?filename=5.5_hr.png&userId=73716 [9]: /c/portal/getImageAttachment?filename=6_elevationmap.png&userId=73716 [10]: /c/portal/getImageAttachment?filename=7_elevationcolor.png&userId=73716 [11]: /c/portal/getImageAttachment?filename=8_speedmap.png&userId=73716 [12]: /c/portal/getImageAttachment?filename=9_speedtime.png&userId=73716 [13]: http://blog.wolfram.com/2009/04/17/mapping-gps-data/ Sander Huisman 2015-09-19T17:56:26Z https://community.wolfram.com/groups/-/m/t/2141352 Hello all :) CUDA is not working on 12.2. Look at this: What I am supposed to do? I also tried by downloading the CUDA packlets: change nothing. I have an NVIDIA RTX 3090 and the drivers are ok. Thank you foe helping me. Regards to all, Jean-Michel Jean-Michel Collard 2020-12-18T02:04:15Z https://community.wolfram.com/groups/-/m/t/2152918 My question is based on the observation that when a new Mathematica version is released (this time being 12.2) some of the functions that don't even receive an update from the previous version often get broken. How is it so that the examples in the documentation are not checked for consistency of operation/results before a new Mathematica version is shipped? I believe that even with a team of 5-6 people in the quality control department (assuming there is any) it is possible to check the examples for all listed functions in Mathematica in about a week. Why is such a simple task and simple expectation so hard to meet? The issue at the end is that a buggy release will cause many of the mission critical functions for say an end user to break. It is a pity that I have to install not one version (that I can fully trust) but keep four versions of Mathematica (11.3, 12.0,12.1 and 12.2) simultaneously (grabbing over 50 GB). Reason: because some things work in one version and the others in another version. Please do enlighten me how hard are the user expectations to be met. We do not want more and more functions; we just want the functions to work reliably and correctly. There seems to be issues with the quality control here that needs to be sorted before releasing future versions. Take this simple example: ReplacePixelValue did not receive any update since 2014 (version 10). Then how come the second example in its documentation (in the "Applications" subsection) cease to function properly. Furthermore, I am attaching a notebook with another example for this particular function to demonstrate that something that works perfectly in 12.0 and 12.1 fails in the 12.2 release. &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/1cb0dbd1-e7cb-48cf-abd1-1324cf87e89e Ali Hashmi 2021-01-02T15:53:14Z