Search Results

Search found 3436 results on 138 pages for 'math grad'.

Page 108/138 | < Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >

  • Surface Area of a Spheroid in Python

    - by user3678321
    I'm trying to write a function that calculates the surface area of a prolate or oblate spheroid. Here's a link to where I got the formulas (http://en.wikipedia.org/wiki/Prolate_spheroid & http://en.wikipedia.org/wiki/Oblate_spheroid). I think I've written them wrong, but here is my code so far; from math import pi, sqrt, asin, degrees, tanh def checkio(height, width): height = float(height) width = float(width) lst = [] if height == width: r = 0.5 * width surface_area = 4 * pi * r**2 surface_area = round(surface_area, 2) lst.append(surface_area) elif height > width: #If spheroid is prolate a = 0.5 * width b = 0.5 * height e = 1 - a / b surface_area = 2 * pi * a**2 * (1 + b / a * e * degrees(asin**-1(e))) surface_area = round(surface_area, 2) lst.append(surface_area) elif height < width: #If spheroid is oblate a = 0.5 * height b = 0.5 * width e = 1 - b / a surface_area = 2 * pi * a**2 * (1 + 1 - e**2 / e * tanh**-1(e)) surface_area = round(surface_area, 2) lst.append(surface_area, 2) return lst

    Read the article

  • Recursive Functions for Beginners?

    - by cam
    I'm looking for a few recursive function examples, preferably ones that show increase in complexity. I understand basic recursive functions, but I'm having trouble implementing them in my code. I've never used them in my code before, and I know it doesn't always call for it, but I'd like to try. Is there a good resource with examples, and maybe challenges of some sort? Or even some simple math problems (Project Euler-style?) that I could use recursion on? For examples, I prefer C#, but anything works.

    Read the article

  • Is the use of union in this matrix class completely safe?

    - by identitycrisisuk
    Unions aren't something I've used that often and after looking at a few other questions on them here it seems like there is almost always some kind of caveat where they might not work. Eg. structs possibly having unexpected padding or endian differences. Came across this in a math library I'm using though and I wondered if it is a totally safe usage. I assume that multidimensional arrays don't have any extra padding and since the type is the same for both definitions they are guaranteed to take up exactly the same amount of memory? template<typename T> class Matrix44T { ... union { T M[16]; T m[4][4]; } m; }; Are there any downsides to this setup? Would the order of definition make any difference to how this works?

    Read the article

  • Collection type generated by for with yield

    - by Jesper
    When I evaluate a for in Scala, I get an immutable IndexedSeq (a collection with array-like performance characteristics, such as efficient random access): scala> val s = for (i <- 0 to 9) yield math.random + i s: scala.collection.immutable.IndexedSeq[Double] = Vector(0.6127056766832756, 1.7137598183155291, ... Does a for with a yield always return an IndexedSeq, or can it also return some other type of collection class (a LinearSeq, for example)? If it can also return something else, then what determines the return type, and how can I influence it? I'm using Scala 2.8.0.RC3.

    Read the article

  • Why does DateTime to Unix time use a double instead of an integer?

    - by Earlz
    I'm needing to convert a DateTime to a Unix timestamp. So I googled it looking for some example code In just about all the results I see, they use double as the return for such a function, even when explicitly using floor to convert it to an integer. Unix timestamps are always integers. So what problem is there with using either long or int instead of double? static double ConvertToUnixTimestamp(DateTime date) { DateTime origin = new DateTime(1970, 1, 1, 0, 0, 0, 0); TimeSpan diff = date - origin; return Math.Floor(diff.TotalSeconds); }

    Read the article

  • Load a single symbol from a LaTeX package

    - by Martijn
    When using the MnSymbol package, pdflatex gives two font warnings: LaTeX Font Warning: Encoding 'OMS' has changed to 'U' for symbol font (Font) 'symbols' in the math version 'normal' on input line 120. LaTeX Font Info: Overwriting symbol font 'symbols' in version 'normal' (Font) OMS/cmsy/m/n --> U/MnSymbolF/m/n on input line 120. It turns out that this is probably due to a clash with the AMSSymb package. Since I need just a few symbols from the package: is there a way to load one symbol from a package, in stead of all?

    Read the article

  • How can you get the first digit in an int (C#)?

    - by Dinah
    In C#, what's the best way to get the 1st digit in an int? The method I came up with is to turn the int into a string, find the 1st char of the string, then turn it back to an int. int start = Convert.ToInt32(curr.ToString().Substring(0, 1)); While this does the job, it feels like there is probably a good, simple, math-based solution to such a problem. String manipulation feels clunky. Edit: irrespective of speed differences, mystring[0] instead of Substring() is still just string manipulation

    Read the article

  • F# operator over-loading question

    - by jyoung
    The following code fails in 'Evaluate' with: "This expression was expected to have type Complex but here has type double list" Am I breaking some rule on operator over-loading on '(+)'? Things are OK if I change '(+)' to 'Add'. open Microsoft.FSharp.Math /// real power series [kn; ...; k0] => kn*S^n + ... + k0*S^0 type Powers = double List let (+) (ls:Powers) (rs:Powers) = let rec AddReversed (ls:Powers) (rs:Powers) = match ( ls, rs ) with | ( l::ltail, r::rtail ) -> ( l + r ) :: AddReversed ltail rtail | ([], _) -> rs | (_, []) -> ls ( AddReversed ( ls |> List.rev ) ( rs |> List.rev) ) |> List.rev let Evaluate (ks:Powers) ( value:Complex ) = ks |> List.fold (fun (acc:Complex) (k:double)-> acc * value + Complex.Create(k, 0.0) ) Complex.Zero

    Read the article

  • updating a shape in scene with a for loop using javafx

    - by Susanta
    Following is a code fragment. I am updating a rectangle using a for loop when a button is pressed. This is a model for my ultimate intention of showing visualization of data model as it changes large number of times inside a for loop. It works but I see only one change. Now since I am changing the width randomly I should see large number of changes. It seems I am making a wrong assumption on something basic. The code goes below: 7 var rec: Rectangle = Rectangle { 8 x: 10, y: 10 9 width: 140, height: 90 10 fill: Color.BLACK 11 } 12 13 Stage { 14 title: "MyApp" 15 scene: Scene { 16 width: 200 17 height: 200 18 content: [ 19 rec, 20 Button { 21 text: "Button" 22 action: function () { 23 for (i in [1..999]) { 24 rec.width = 25 + java.lang.Math.random()*50; 25 } 26 } 27 } 28 ] 29 } 30 }

    Read the article

  • Add time to a Date object in javascript

    - by baiano
    I am trying to add time to a Date object in javascript but am not getting the results that I am expecting. I am trying to pull a timer off of the page and add it to the current time to get the unix timestamp value of when the timer will hit zero. The time on the page is displayed as " HH:MM:SS ". This is what I have: time=getTimerText.split(":"); seconds=(time[0]*3600+time[1]*60+time[2])*1000; to convert the time into milliseconds. fDate=new Date(); fDate.setTime(fDate.getTime()+seconds); add the milliseconds to the javascript timestamp alert(Math.round(fDate.getTime() / 1000)); convert the javascript timestamp to a unix timestamp Since the timer is counting down I should get the same result every time i run the script, but I don't. Can anyone see what I might be doing wrong here?

    Read the article

  • Can't append to second container

    - by George Katsanos
    I have the following script: (function($) { $.fn.easyPaginate = function(options){ var defaults = { step: 4, delay: 100, numeric: true, nextprev: true, controls: 'pagination', current: 'current' }; var options = $.extend(defaults, options); var step = options.step; var lower, upper; var children = $(this).children(); var count = children.length; var obj, next, prev; var page = 1; var timeout; var clicked = false; function show(){ clearTimeout(timeout); lower = ((page-1) * step); upper = lower+step; $(children).each(function(i){ var child = $(this); child.hide(); if(i>=lower && i<upper){ setTimeout(function(){ child.fadeIn('fast') }, ( i-( Math.floor(i/step) * step) )*options.delay ); } if(options.nextprev){ if(upper >= count) { next.addClass('stop'); } else { next.removeClass('stop'); }; if(lower >= 1) { prev.removeClass('stop'); } else { prev.addClass('stop'); }; }; }); $('li','#'+ options.controls).removeClass(options.current); $('li[data-index="'+page+'"]','#'+ options.controls).addClass(options.current); if(options.auto){ if(options.clickstop && clicked){}else{ timeout = setTimeout(auto,options.pause); }; }; }; function auto(){ if(upper <= count){ page++; show(); } else { page--; show(); } }; this.each(function(){ obj = this; if(count>step){ var pages = Math.floor(count/step); if((count/step) > pages) pages++; var ol = $('<ol id="'+ options.controls +'" class="pagin"></ol>').insertAfter(obj); if(options.nextprev){ prev = $('<li class="prev">prev</li>') .appendTo(ol) .bind('click', function() { //check to see if there are any more pages in the negative direction if (page > 1) { clicked = true; page--; show(); } }); } if(options.numeric){ for(var i=1;i<=pages;i++){ $('<li data-index="'+ i +'">'+ i +'</li>') .appendTo(ol) .click(function(){ clicked = true; page = $(this).attr('data-index'); show(); }); }; }; if(options.nextprev){ next = $('<li class="next">next</li>') .appendTo(ol) .bind('click', function() { //check to see if there are any pages in the positive direction if (page < (count / 4)) { clicked = true; page++; show(); } }); } show(); }; }); }; })(jQuery); jQuery(function($){ $('ul.news').easyPaginate({step:4}); }); which is a carousel-like plugin that produces this html structure for the navigation: <ol id="pagination" class="pagin"><li class="prev">prev</li><li data-index="1" class="">1</li><li data-index="2" class="">2</li><li data-index="3" class="current">3</li><li class="next stop">next</li></ol> And all I want is to enclose this list in a div. Seems simple, but appendTo doesn't want to cooperate with me, or I'm doing something wrong (I'd appreciate if you would help me understand what that is..) So I'm modifying as such: var ol = $('<ol id="'+ options.controls +'" class="pagin"></ol>'); var tiv = $('<div id="lala"></div>'); ol.appendTo('#lala'); tiv.insertAfter(obj); I know how to chain, but I'm in "debugging" mode trying to understand why I don't get the result I imagine I would get: <div id="lala> <ol id="pagination><li>...... </li></ol> </div> I tried putting some console.log's to see the status of my variables but couldn't find something useful.. I guess there's something with DOM insertion I don't get.

    Read the article

  • Is there anything wrong with a class with all static methods?

    - by MatthewMartin
    I'm doing code review and came across a class that uses all static methods. The entrance method takes several arguments and then starts calling the other static methods passing along all or some of the arguments the entrance method received. It isn't like a Math class with largely unrelated utility functions. In my own normal programming, I rarely write methods where Resharper pops and says "this could be a static method", when I do, they tend to be mindless utility methods. Is there anything wrong with this pattern? Is this just a matter of personal choice if the state of a class is held in fields and properties or passed around amongst static methods using arguments?

    Read the article

  • OCaml Summation

    - by Supervisor
    I'm trying to make a function in OCaml which does the summation function in math. I tried this: sum n m f = if n = 0 then 0 else if n > m then f else f + sum (n + 1) m f;; However, I get an error - "Characters 41-44: else f * sum(n + 1) m f;; Error: Unbound value sum and sum is underlined (has carrot signs pointing to it) I looked at this: Simple OCaml exercise It's the same question, but I see a lot of other things that I do not have. For example, for my n = m case, I do not have f n and then in the else case, I do not have f m. Why do you need f n if you want the function to return an integer? D: What's the problem!? Thanks in advance.

    Read the article

  • Python frequency detection

    - by Tsuki
    Ok what im trying to do is a kind of audio processing software that can detect a prevalent frequency an if the frequency is played for long enough (few ms) i know i got a positive match. i know i would need to use FFT or something simiral but in this field of math i suck, i did search the internet but didn not find a code that could do only this. the goal im trying to accieve is to make myself a custom protocol to send data trough sound, need very low bitrate per sec but im also very limited on the transmiting end so the recieving software will need to be able custom (cant use an actual hardware/software modem) also i want this to be software only (no additional hardware except soundcard) thanks alot for the help.

    Read the article

  • converting tag number to int

    - by Ehtesham Sajed
    i m using Visual C++2008. i've assigned tag value=2 of all buttons from button property(using drag n drop). now i want to make some math calculation with tag value. need to change it in int. what is the default data type tag? i used this code, //code sample if(((int)this-button1-Tag)((int)this-button2-Tag)((int)this-button3-Tag)==50) { ........ //i.e, if tag value of button1*tag value of button2*tag value of button 3==50 then... ........ } generated following run time error on a messegebox An unhandled exception of type 'System.InvalidCastException' occurred in learncpp1.exe Additional information: Specified cast is not valid.

    Read the article

  • how to calculate the beginning of a day given milliseconds?

    - by conman
    i want to figure out the time from the beginning of the day given a days milliseconds. so say i'm given this: 1340323100024 which is like mid day of 6/21/2012. now i want the milliseconds from the beginning of the day, which would be 1340262000000 (at least i think that's what it's supposed to be.) how do i get 1340262000000 from 1340323100024? i tried doing Math.floor(1340323100024/86400000) * 86400000 but that gives me 1340236800000, which if i create a date object out of it, says its the 20th. i know i can create a date object from 1340323100024, then get the month, year, and date, to create a new object which would give me 1340262000000, but i find it ridiculous i can't figure out something so simple. any help would be appreciated. btw, i'm doing this in javascript if it makes any difference.

    Read the article

  • What is your favorite Project Euler question?

    - by A. Rex
    I was searching around for questions related to Project Euler on Stack Overflow, and it seems that there were plenty of people asking about it, and even more people recommending it, whether for fun, to learn a new language, or to practice for interview questions. All this seems to imply to me that there are lots of people on SO that solve Project Euler problems now and then. I just started, so I was wondering: What was your favorite Project Euler question? Why? Did you think of a clever trick, or did you learn some new math, or did you discover a feature of a new programming language? (If possible, please include the actual question in your answer.)

    Read the article

  • Background subtracting in MATLAB

    - by eiphyomin
    I'm looking to do background subtracting on an image. I'm new to MATLAB and new to image processing/analysis, so sorry if any of this sounds stupid. 1) Other than imsubtract() are there other ways to do background subtracting (besides comparing one image to another)? 2) In the Math Works explanation for imsubtract() why do they make their structuring element a disk? This seems rather difficult so far because every time I try something, I end up not only subtracting the noisy background but also losing the parts of the image I want to look at!

    Read the article

  • Programming Exercises for Learning Purposes?

    - by cam
    Are there any programming exercises that apply to any language? Before I got my first job, I thought I knew C# pretty well, then I was thrown right into the deep end, and now I know I have a good command over the language. I would like to apply the same method to other languages, but unfortunately, I'm sort of stuck with C# at work. Ideally, something similar (but broader in scope) to Project Euler is ideal. Project Euler helped me learn a ton of C++/F#, some math, algorithms, handling bignums, etc. I'm looking for something like this.

    Read the article

  • How do I display and calculate numbers from a database on iPhone?

    - by JoshD
    I am new to designing apps and have a basic understand of Ob-C and how everything works. What I would like to do is have two tabs, one is a home screen that displays numbers and percentages that are entered on the second tab. The user will be able to store that information and refer back to it and update it. What is the best way to complete that math from the database to the "home screen"? Any tutorials, advice is great! Thanks.

    Read the article

  • One Database Field to Hold Survey Answer

    - by yar
    Skipping the question of whether this is bad design (and the question of why I would want/need to do this), I'm just wondering if my 'math' is right... I have n things that need to be put in order (n is always less than 5): thing1 thing2 thing3 ... and I'd like to store these results in a single integer for thing. My initial thought is that (obviously the code will not look like this): thing = thing1 * 1 + thing2 * 2 + thing3 * 4 + thing5 * 8 will always give me a unique value, and that any value for thing will always translate back to its values for thing1...thingn. Is this correct?

    Read the article

  • Hashing and salting values

    - by Avanst
    I am developing a small web app that internally authenticates users. Once the user is authenticated my web app then passes some information such as userID and Person's name to a third party web application. The third party developer is suggesting that we hash and salt the values. Forgive my ignorance, but what exactly does that mean? I am writing the app in Java. So what I am planning on doing is hashing the userID, Person's name, and some Math.random() value as the salt with Apache Commons Digest Utils SHA512 and passing that hashed string along with the userID and person's name. Is that the standard practice? I should be passing the third party the salt as well correct?

    Read the article

  • Cross vertion line matching.

    - by BCS
    I'm considering how to do automatic bug tracking and as part of that I'm wondering what is available to match source code line numbers (or more accurate numbers mapped from instruction pointers via something like addr2line) in one version of a program to the same line in another. (Assume everything is in some kind of source control and is available to my code) The simplest approach would be to use a diff tool/lib on the files and do some math on the line number spans, however this has some limitations: It doesn't handle cross file motion. It might not play well with lines that get changed It doesn't look at the information available in the intermediate versions. It provides no way to manually patch up lines when the diff tool gets things wrong. It's kinda clunky Before I start diving into developing something better: What already exists to do this? What features do similar system have that I've not thought of?

    Read the article

  • How to calculate end-point at a given center plus an radius and angle?

    - by mystify
    I'm trying to do some basic quartz core drawing with arcs, but have an F in math ;-) I have a point: CGPoint center = CGPointMake(100.0f, 100.0f); CGFloat radius = 50.0f; CGFloat startAngle = 20.0f / 180.0f * M_PI; CGFloat endAngle = 150.0f / 180.0f * M_PI; CGContextAddArc(c, center.x, center.y, radius, startAngle, endAngle, 0); Now I want to draw a little dot on the middle of the arc. I mean, not the center point, but the little curve (arc) which is made up between the angles 20-150 degrees. I looked into quartz but unfortunately, there seems no helper function to calculate this. Probably some hardcore trigonometric logic with atan and stuff of this kind needed?

    Read the article

  • Trying to zoom in on an arbitrary rect within a screen-aligned quad.

    - by mos
    I've got a screen-aligned quad, and I'd like to zoom into an arbitrary rectangle within that quad, but I'm not getting my math right. I think I've got the translate worked out, just not the scaling. Basically, my code is the following: // // render once zoomed in glPushMatrix(); glTranslatef(offX, offY, 0); glScalef(?wtf?, ?wtf?, 1.0f); RenderQuad(); glPopMatrix(); // // render PIP display glPushMatrix(); glTranslatef(0.7f, 0.7f, 0); glScalef(0.175f, 0.175f, 1.0f); RenderQuad(); glPopMatrix(); Anyone have any tips? The user selects a rect area, and then those values are passed to my rendering object as [x, y, w, h], where those values are percentages of the viewport's width and height.

    Read the article

< Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >