[{"data":1,"prerenderedAt":356},["ShallowReactive",2],{"project-9131706":3},{"id":4,"name":5,"line":6,"line_source":7,"title":8,"url":9,"domain":10,"maker":11,"posted_at":12,"year":13,"points":14,"comments":15,"rank_in_year":16,"shown_in_year":17,"top":18,"tier":19,"category":20,"subcategory":21,"format":22,"keywords":23,"reception":29,"sentiment":30,"stance_mix":31,"scored_comments":36,"aspects":37,"strip":46,"post_text":48,"what":49,"said":90,"maker_in_thread":196,"shape":203,"grid":208,"attempts":319,"same_week":320,"maker_shows":34,"maker_hidden":348,"reader_version":349,"card":350},"9131706","Circles, Sines & Signals","Interactive Essay on Signals, Sampling and the Fourier Transform","title","Show HN: Interactive Essay on Signals, Sampling and the Fourier Transform","http:\u002F\u002Fjackschaedler.github.io\u002Fcircles-sines-signals\u002F","jackschaedler.github.io","jackschaedler",1425302809,2015,293,43,52,2565,3,"legend","learning_science","interactive essay","web_app",[24,25,26,27,28],"fourier transform","signal processing","sampling","aliasing","interactive learning","loved",0.606,{"positive":32,"neutral":33,"mixed":34,"critical":35},22,7,4,1,34,{"docs":38,"idea":40,"design":42,"performance":43,"execution":44,"pricing":45},{"positive":18,"critical":39},0,{"positive":41,"critical":39},11,{"positive":18,"critical":39},{"positive":39,"critical":35},{"positive":39,"critical":39},{"positive":35,"critical":39},[47,39,18,39,39,39,39,47,18,47,47,47,47,35,47,18,18,47,39,47,47,18,39,39,39,47,47,18,18,18,18,47,47,47,18,47,47,47,47,47],5,null,{"problem":50,"audience":62,"pricing":48,"motivation":48,"time_to_build":48,"stack":73,"openness":88,"stage":89,"team_size":88},{"value":51,"source":52,"evidence":53},"Hard-to-grasp signals and Fourier transform concepts taught with static textbook diagrams","commenter",[54,58],{"id":55,"by":56,"text":57},"9133205","dankoss","The dynamic visualizations are terrific here, I find that signals problems in textbooks are hard to understand when they are static. Awesome job!",{"id":59,"by":60,"text":61},"9132725","zwieback","Like!! It took me a while to chew through signals and FT back in school (before the web) so I really appreciate how this is bringing browser-based animations to the general…",{"value":63,"source":52,"evidence":64},"Students and learners of signal processing and DSP",[65,69],{"id":66,"by":67,"text":68},"9133039","erc11","This is fantastic. I've been looking for something exactly like this to learn DSP. My brain learns best with kinds of resources. Well done!",{"id":70,"by":71,"text":72},"9133153","Pluizer","I registered an account just to say thanks, this is brilliant! Exactly what I was looking for.",[74,81],{"value":75,"source":52,"evidence":76},"D3 animations",[77],{"id":78,"by":79,"text":80},"9133428","protonfish","The D3 animations work great for me in Chrome, but my Firefox is choking on them - especially this one.",{"value":82,"source":52,"evidence":83},"MathJax for equations",[84],{"id":85,"by":86,"text":87},"9134799","Kronopath","That's because you're accessing the site from HTTPS, or you have HTTPS Everywhere installed which is doing it for you. I think he's loading MathJax as HTTP, which means it gets…","unknown","launched",{"praise":91,"objections":119,"requests":136,"questions":169,"alternatives":181},[92,108],{"value":93,"source":52,"evidence":94},"Clear, beautifully crafted interactive writing that beats static textbooks",[95,99,103,107],{"id":96,"by":97,"text":98},"9133775","geographomics","This is a wonderful piece of work. Exceptionally clear writing and excellent use of interactivity. One minor bug report, the mathematical pi symbol (U+1D6D1) used in the unit…",{"id":100,"by":101,"text":102},"9133190","gdubs","This is an _incredibly_ well-crafted piece of work. I mean -- my god -- the pressure wave animation? [1] 1: http:\u002F\u002Fjackschaedler.github.io\u002Fcircles-sines-signals\u002Fsound.html",{"id":104,"by":105,"text":106},"9135560","Sainth","This is simply beautiful",{"id":55,"by":56,"text":57},{"value":109,"source":52,"evidence":110},"Would have helped while learning the subject",[111,115],{"id":112,"by":113,"text":114},"9132813","streptomycin","Normally I'd just upvote and move on, but this is really fucking good. For example, I wish I could have seen something like that \"Sine Wave Aliasing\" page when I was learning…",{"id":116,"by":117,"text":118},"9131933","deitcher","I wish they could have done things like this when I was learning signals and transforms as an undergrad. But interactive didn't really exist in the early 90s.",[120,124,132],{"value":121,"source":52,"evidence":122},"Site is slow in Firefox on the D3 animations",[123],{"id":78,"by":79,"text":80},{"value":125,"source":52,"evidence":126},"MathJax equations fail to render over HTTPS",[127,131],{"id":128,"by":129,"text":130},"9134188","jfoutz","It seems like the equation processing gets messed late in section 4 - $$ \\mathrm{DFT}[k] = \\sum_{n=0}^{N-1} \\mathrm{x}[n] \\cdot (cos(\\varphi) - sin(\\varphi)i) \\\\ where \\quad…",{"id":85,"by":86,"text":87},{"value":133,"source":52,"evidence":134},"Unicode pi symbol not displayed in Chrome on Windows",[135],{"id":96,"by":97,"text":98},[137,148,162],{"value":138,"source":52,"evidence":139},"Add convolution and Dirac delta sections",[140,144],{"id":141,"by":142,"text":143},"9133569","calebreach","This is great! I'd love to see sections on convolution, the Dirac delta function, and the continuous (possibly multi-dimensional) Fourier transform.",{"id":145,"by":146,"text":147},"9133993","sbuccini","Seconded on convolution and the Dirac delta.",{"value":149,"source":52,"evidence":150},"Write more interactive articles and series on other topics",[151,155,159],{"id":152,"by":153,"text":154},"9134631","dm8","This is great! Please write interactive articles on similar topics.",{"id":156,"by":157,"text":158},"9134867","TheOtherHobbes","This is truly outstanding. I'd love to see an entire series done like this. Maybe you could Kickstarter this, and use it as a template for a series of DSP\u002FElectronics\u002FPhysics…",{"id":160,"by":11,"text":161},"9133189","Thanks! Let me know if there are other topics you'd like covered, or areas that need more explanation.",{"value":163,"source":52,"evidence":164},"Combine the articles into a single page instead of Next links",[165],{"id":166,"by":167,"text":168},"9134248","danabramov","Really great. One nitpick: I looked 10 seconds for \"Next\" link. Would be better as a single article IMO.",[170],{"value":171,"source":52,"evidence":172},"Was the interactive content written by hand or with a tool",[173,177],{"id":174,"by":175,"text":176},"9195340","CookieMon","Did you use a tool to make the interactive diagrams, or just write all of them by hand? (I can imagine myself forever tweaking each diagram, and having to cut back on them, but…",{"id":178,"by":179,"text":180},"9135137","rbonvall","Hi Jack, awesome work! Did you write the HTML by hand or did you use or write some static generator? I'd love to have sidenotes like yours automatically generated and positioned.",[182,189],{"value":183,"source":52,"evidence":184},"Wolfram Demonstrations",[185],{"id":186,"by":187,"text":188},"9135858","shas3","This is incredible. I wish more professors in universities incorporated this stuff in their teaching. I occasionally use Wolfram Demonstrations:…",{"value":190,"source":52,"evidence":191},"Steven Wittens' quaternion animations",[192],{"id":193,"by":194,"text":195},"9134509","malingo","I found this example by Steven Wittens to be remarkably well done: http:\u002F\u002Facko.net\u002Fblog\u002Fanimate-your-way-to-glory-pt2\u002F See the section \"Blowing up the Death Star\" and note that…",{"comments":197,"answered":39,"key":198},2,[199,200],{"id":160,"text":161},{"id":201,"text":202},"9133185","Wow, that really means a lot. Thank you! Really glad to hear that you are finding it useful. Please send along your feedback and questions if anything doesn't make sense or is…",{"commenters":204,"max_depth":205,"maker_replies":197,"first_comment_mins":206,"lifespan_hours":207},39,6,56,253,[209,211,213,217,221,225,227,228,230,231,234,237,238,240,242,245,246,248,250,252,253,255,258,260,261,263,266,267,269,274,276,278,282,286,288,292,296,300,302,305,309,313,317],[112,39,47,210,113,39],"project\u002Fpositive\u002Fdocs",[160,39,39,212,11,35],"maker\u002Fneutral\u002Fnone",[214,39,18,215,216,39],"9133370","project\u002Fneutral\u002Fidea","shorodei",[218,39,39,219,220,39],"9133481","other\u002Fneutral\u002Fnone","cbd1984",[222,39,39,223,224,39],"9133604","commenter\u002Fneutral\u002Fnone","GFK_of_xmaspast",[226,39,39,223,220,39],"9135542",[193,39,39,219,194,39],[141,39,47,229,142,39],"project\u002Fpositive\u002Fidea",[145,39,18,215,146,39],[232,35,47,229,233,39],"9133989","tomek_zemla",[235,197,47,210,236,39],"9133372","SandB0x",[116,18,47,229,117,39],[100,34,47,239,101,39],"project\u002Fpositive\u002Fdesign",[78,34,35,241,79,39],"project\u002Fcritical\u002Fperformance",[243,34,18,215,244,39],"9135805","davyjones",[59,47,47,210,60,39],[96,205,18,247,97,39],"project\u002Fmixed\u002Fexecution",[166,33,18,249,167,39],"project\u002Fmixed\u002Fdesign",[70,251,47,229,71,39],8,[201,251,39,212,11,35],[156,254,47,229,157,39],9,[256,254,47,257,233,39],"9135039","project\u002Fpositive\u002Fpricing",[128,259,18,247,129,39],10,[85,259,39,223,86,39],[262,259,39,223,129,39],"9134821",[264,259,39,223,265,39],"9135860","schoen",[66,41,47,229,67,39],[186,268,47,229,187,39],12,[270,271,47,272,273,39],"9132626",13,"project\u002Fpositive\u002Fnone","pdh",[174,275,18,212,175,39],14,[178,277,18,212,179,39],15,[279,277,18,280,281,39],"9135731","maker\u002Fneutral\u002Fdesign","Nzen",[283,284,18,249,285,39],"9133901",16,"hashmymustache",[55,287,47,239,56,39],17,[289,290,47,229,291,39],"9135155",18,"JoelHobson",[293,294,47,229,295,39],"9135910",19,"arunabh",[297,298,18,215,299,39],"9133803",20,"cozzyd",[152,301,47,229,153,39],21,[303,32,47,229,304,39],"9134924","alexdmiller",[306,307,47,272,308,39],"9134170",23,"valerian",[310,311,47,272,312,39],"9134053",24,"lynchdt",[314,315,47,272,316,39],"9161873",25,"tsenkov",[104,318,47,239,105,39],26,[],[321,326,330,335,340,345],{"id":322,"name":323,"points":324,"category":325},"9144271","OpenLoopz",373,"productivity",{"id":327,"name":328,"points":329,"category":325},"9145007","Ghostnote",301,{"id":331,"name":332,"points":333,"category":334},"9112803","GitHub Awards",137,"dev_tools",{"id":336,"name":337,"points":338,"category":339},"9117238","grack.com",134,"creative",{"id":341,"name":342,"points":343,"category":344},"9118491","Paz",90,"infrastructure",{"id":346,"name":347,"points":343,"category":325},"9137684","VisualCV",false,"v2",{"id":351,"name":5,"line":6,"ai":348,"cat":20,"year":13,"points":14,"comments":15,"rec":29,"s":352,"top":18,"kw":353,"maker":11,"domain":10,"tier":19,"attempts":39,"strip":354,"url":9,"mix":355,"praise":93,"objection":121,"sub":21},9131706,0.61,[24,25,26,27,28],"5030000535555153350553000553333555355555",[32,33,34,35],1794036528914]