Search Results

Search found 9032 results on 362 pages for 'fast math'.

Page 59/362 | < Previous Page | 55 56 57 58 59 60 61 62 63 64 65 66  | Next Page >

  • analyzing hashes

    - by calccrypto
    Is anyone willing to devote some time to helping me analyze a (hopefully cryptographically secure) hash? I honestly have no idea what im doing, so i need someone to show me how to, to teach me. almost all of the stuff ive found online have been really long, tedious, and vague the code is in python because for some reason i dont know c/c++. all i know about the hash: 1. there are no collisions (so far) and 2. differences between two similar inputs results in wildly different differences and please dont tell me that if i dont know what im doing, i shouldnt be doing it.

    Read the article

  • How do i know if this is random enough?

    - by David
    I wrote a program in java that rolls a die and records the total number of times each value 1-6 is rolled. I rolled 6 Million times. Here's the distribution: #of 0's: 0 #of 1's: 1000068 #of 2's: 999375 #of 3's: 999525 #of 4's: 1001486 #of 5's: 1000059 #of 6's: 999487 (0 wasn't an option.) Is this distribution consistant with random dice rolls? What objective statistical tests might confirm that the dice rolls are indeed random enough?

    Read the article

  • How are a session identifiers generated?

    - by Asaf R
    Most web applications depend on some kind of session with the user (for instance, to retain login status). The session id is kept as a cookie in the user's browser and sent with every request. To make it hard to guess the next user's session these session-ids need to be sparse and somewhat random. The also have to be unique. The question is - how to efficiently generate session ids that are sparse and unique? This question has a good answer for unique random numbers, but it seems not scalable for a large range of numbers, simply because the array will end up taking a lot of memory.

    Read the article

  • Built in raytracing?

    - by acidzombie24
    Relating to this question i was wondering if .NET has any libs (or a function) i can use to detect if one point collides with another. I am not sure what angles i should use but is there some function like this func(point src, rect target, angle, distanceOfVision, listPointOrRectOfWalls) Pretty unlikely but i dont know a formula or how to start. Its a quick and dirty prototype. I am thinking of writing the func about but dropping angle and just make line of sight a rectangle and check if any points is between src and target.

    Read the article

  • How to get points that intersect the treadline?

    - by chutsu
    Basically I did the Cavendish experiment, and I have a damped sinusoidal wave plotted on Excel. With Position (mm) against Time (s). My problem is that I have added a tread line through the wave function, and wish to calculate the points of which the wave function intersects the tread line. From this I will then be able to calculate the time period. At the moment I'm just having difficulty getting the intersects.. Thanks

    Read the article

  • Find the centroid of a polygon with weighted vertices

    - by Calle Kabo
    Hi, I know how to find the centroid (center of mass) of a regular polygon. This assumes that every part of the polygon weighs the same. But how do I calculate the centroid of a weightless polygon (made from aerogel perhaps :), where each vertex has a weight? Simplified illustration of what I mean using straight line: 5kg-----------------5kg ^center of gravity 10kg---------------5kg ^center of gravity offset du to weight of vertices Of course, I know how to calculate the center of gravity on a straight line with weighted vertices, but how do I do it on a polygon with weighted vertices? Thanks for your time!

    Read the article

  • I know my Before Tax Pay and my After Tax Pay, how can I work out how much I get taxed?

    - by Pete
    I've been entering some data into an Excel spreadsheet to work out my monthly earnings, etc. and was wondering how I can I find out how much I'm getting taxed? Say this is my current spreadsheet: Hours Worked 37.5 39.5 37.5 30 Hourly Rate $25 $25 $25 $25 Before Tax 937.50 987.50 937.50 750.00 After Tax 260.00 276.00 260.00 ??? How can I use this known data to work out my After Tax pay for the 4th column? :/

    Read the article

  • How to interpolate rotations?

    - by uhuu
    I have two vectors describing rotations; a start rotation A and a target rotation B. How would I best go about interpolating A by a factor F to approach B? Using a simple lerp on the vectors fails to work when more than one dimension needs to be interpolated (i.e. produces undesirable rotations). Maybe building quaternions from the rotation vectors and using slerp is the way to go. But how, then, could I extract a vector describing the new rotation from the resulting quaternion? Thanks in advance.

    Read the article

  • optimized grid for rectangular items

    - by peterchen
    I have N rectangular items with an aspect ratio Aitem (X:Y). I have a rectangular display area with an aspect ratio Aview The items should be arranged in a table-like layout (i.e. r rows, c columns). what is the ideal grid rows x columns, so that individual items are largest? (rows * colums = N, of course - i.e. there may be "unused" grid places). A simple algorithm could iterate over rows = 1..N, calculate the required number of columns, and keep the row/column pair with the largest items. I wonder if there's a non-iterative algorithm, though (e.g. for Aitem = Aview = 1, rows / cols can be approximated by sqrt(N)).

    Read the article

  • summing functions handles in matlab

    - by user552231
    Hi I am trying to sum two function handles, but it doesn't work. for example: y1=@(x)(x*x); y2=@(x)(x*x+3*x); y3=y1+y2 The error I receive is "??? Undefined function or method 'plus' for input arguments of type 'function_handle'." This is just a small example, in reality I actually need to iteratively sum about 500 functions that are dependent on each other. EDIT The solution by Clement J. indeed works but I couldn't manage to generalize this into a loop and ran into a problem. I have the function s=@(x,y,z)((1-exp(-x*y)-z)*exp(-x*y)); And I have a vector v that contains 536 data points and another vector w that also contains 536 data points. My goal is to sum up s(v(i),y,w(i)) for i=1...536 Thus getting one function in the variable y which is the sum of 536 functions. The syntax I tried in order to do this is: sum=@(y)(s(v(1),y,z2(1))); for i=2:536 sum=@(y)(sum+s(v(i),y,z2(i))) end

    Read the article

  • 6^x = 5 equation, how to solve it?

    - by Tom
    If it would be 6^x = 1 or 6^x = 6 or 6^x = 36 it would be extremely easy, but how to solve this equation: 6^x = 5 I don't need an answer, I want to find out how to solve equations like this one, I need solution. Thanks.

    Read the article

  • Can we find out the difference between 2 RGb colors to find out a 3rd color?

    - by AK
    2 colors are mixed together. If i have the RGB for the resultant color and RGB for one of the colors mixed, then somehow i could calculate the 2nd color? I will try to explain visually what i am trying to say. Here is a flickr link http://www.flickr.com/photos/48150615@N08/4407414157 I know that the circle in the middle has an opacity of 20% Is there any way to know the color value of the circle so that i can deduct that to get the same color value as the background color.

    Read the article

  • Arrange points in sequence.

    - by Himadri
    I have some points in 3D which are in a single plane. I want to arrange them in clock wise or counter clockwise order. The points can create a concave or convex polygon in a single plane. Can any body give any suggestions?

    Read the article

  • Question about the mathematical properties of hashes

    - by levand
    Take a commonly used binary hash function - for example, SHA-256. As the name implies, it outputs a 256 bit value. Let A be the set of all possible 256 bit binary values. A is extremely large, but finite. Let B be the set of all possible binary values. B is infinite. Let C be the set of values obtained by running SHA-256 on every member of B. Obviously this can't be done in practice, but I'm guessing we can still do mathematical analysis of it. My Question: By necessity, C ? A. But does C = A?

    Read the article

  • Distance between hyperplanes

    - by michael dillard
    I'm trying to teach myself some machine learning, and have been using the MNIST database (http://yann.lecun.com/exdb/mnist/) do so. The author of that site wrote a paper in '98 on all different kinds of handwriting recognition techniques, available at http://yann.lecun.com/exdb/publis/pdf/lecun-98.pdf. The 10th method mentioned is a "Tangent Distance Classifier". The idea being that if you place each image in a (NxM)-dimensional vector space, you can compute the distance between two images as the distance between the hyperplanes formed by each where the hyperplane is given by taking the point, and rotating the image, rescaling the image, translating the image, etc. I can't figure out enough to fill in the missing details. I understand that most of these are indeed linear operators, so how does one use that fact to then create the hyperplane? And once we have a hyperplane, how do we take its distance with other hyperplanes?

    Read the article

  • C - How to implement Set data structure?

    - by psihodelia
    Is there any tricky way to implement a set data structure (a collection of unique values) in C? All elements in a set will be of the same type and there is a huge RAM memory. As I know, for integers it can be done really fast'N'easy using value-indexed arrays. But I'd like to have a very general Set data type. And it would be nice if a set could include itself.

    Read the article

  • Interesting task using random numbers only

    - by psihodelia
    Given any number of the random real numbers from the interval [0,1] is there exist any method to construct a floating point number with zero decimal part? Your algorithm can use only random() function calls and no variables or constants. No constants and variables are allowed, no type casting is allowed. You can use for/while, if/else or any other programming language operands.

    Read the article

< Previous Page | 55 56 57 58 59 60 61 62 63 64 65 66  | Next Page >