Projection Definition and 409 Threads

  1. Shackleford

    Orthogonal Projection in Inner Product Space with Dimension 2 and Basis {1,x}

    I found a final answer online, but my vector is slightly different. I haven't been able to catch my mistake. I'm supposed to find the orthogonal projection of the given vector on the given subspace W of the the inner product space V. P1 has dimension 2 and basis = {1,x}...
  2. J

    Proving Open Mapping of Canonical Projection in Normed Vector Space

    Homework Statement Let (X,||\cdot||) be a normed vector space and suppose that Y is a closed vector subspace of X. Show that the map ||x||_1=\inf_{y \in Y}||x-y|| defines a pseudonorm on X. Let (X/Y,||\cdot||_1) denote the normed vector space induced by ||\cdot||_1 and prove that the...
  3. Matterwave

    Understanding the Inverse of a Fiber Bundle Projection Map

    Hey guys, I've often seen in the definition of a Fiber bundle a projection map \pi: E\rightarrow B where E is the fiber bundle and B is the base manifold. This projection is used to project each individual fiber to its base point on the base manifold. I then see a lot of references to...
  4. Q

    Ket Notation - Effects of the Projection Operator

    Ket Notation -- Effects of the Projection Operator Homework Statement From Sakurai's Modern Quantum Mechanics (Revised Edition), it is just deriving equation 1.3.12. Homework Equations \begin{eqnarray*}\langle \alpha |\cdot (\sum_{a'}^N |a'\rangle \langle a'|) \cdot|\alpha \rangle...
  5. V

    Define Angle of Projection with The Given Parameters

    Homework Statement A projectile is launched with a speed v at an angle theta above the horizontal. Ignore air resistance. Derive an expression for the angle theta in terms of the parameters of the problem such that the horizontal distance from the launch of the object is N times greater than...
  6. D

    Projection up an inclined plane

    Homework Statement A particle is projected from a point P on an inclined plane, up the line of greatest slope through P, with initial speed V. The angle of the plane to the horizontal is θ. (i) If the plane is smooth, and the particle travels for a time \frac{2Vcosθ}{g} before coming...
  7. T

    Scalar projection - finding distance between line and point

    Using a scalar projections how do you show that the distance from a point P(x1,y1) to line ax + by + c = 0 is \frac{|ax1 +b y1 + c|}{\sqrt{a^2 +b^2}} I do not know how to approach this, please provide some guidance.
  8. T

    Projection of a point onto a line in 3-space.

    I am working on an implementation of the Gilbert–Johnson–Keerthi distance algorithm and am having difficulty with some of the more general math involved. I am able to find the projection of a point onto a plane because I'm given at least three points on the plane and the point that is to be...
  9. T

    Is There a Method to Accurately Calculate Depth of Field in Video Projection?

    Dear all, I have a question concerning Depth of Field –*I'm trying to find a depth of field calculation method that applies for video projection. Background info is that I often have projection on non-planar surfaces and like to find a method that allows to calculate (without trying out) if...
  10. L

    Parametric Sphere Projection: A Function for Projecting Points onto a Sphere

    I just want to make sure my thinking is correct with a problem I'm working on. I'm trying to write a function that will take a point on a plane above a sphere, and then project it onto that sphere. From there project the point onto the x,y plane by following the normal vector of the sphere I...
  11. C

    Projection of meteorology radar images onto a sphere

    Hello everybody, I am working on a project for merging the images of multiple meteorology radars covering a large area. I would like to project each of the images onto a spherical surface and merge them. Do you know if there is a piece of software that can help me with that? I can develop in...
  12. U

    Ev(Unit Vector) and projection of a vector in a dot product

    So my book says Lets suppose, We have two vector v and u w=projection of u ev= unit vector θ=angle between the two w=(u.ev)ev or w=( (u.v)/(v.v) )v Now, the second equation is fairly easy to understand if we understand the first one because ev= v / |v| What is...
  13. M

    Hiker climbing, find the curve of projection of path on xy plane

    Homework Statement a.) A hiker is climbing a mountain whose height is z = 1000 - 2x**2 - 3y**2. When he is at the point (1,1,995) in what direction should he move in order to ascent as rapidly as possible? b.) If he continues along a path of steepest ascent, obtain the equation of the curve...
  14. V

    A problem on finding orthogonal basis and projection

    Use the inner product <f,g> = integral f(x) g(x) dx from 0 to 1 for continuous functions on the inerval [0, 1] a) Find an orthogonal basis for span = {x, x^2, x^3} b) Project the function y = 3(x+x^2) onto this basis. --------------------------------------------------------- I know the...
  15. V

    A problem on finding orthogonal basis and projection

    Use the inner product <f,g> = integral f(x) g(x) dx from 0 to 1 for continuous functions on the inerval [0, 1] a) Find an orthogonal basis for span = {x, x^2, x^3} b) Project the function y = 3(x+x^2) onto this basis. --------------------------------------------------------- I know the...
  16. C

    Projection of vector on a plane

    How do I find a vector which is the projection of another vector onto a plane? By projection, I mean perpendicular projection onto this plane. I know that this vector must lie in the plane and have a minimum angle with the original vector, but it seems like setting up the problem in this...
  17. N

    8 orthogonal projection innequality

    8) U=\{x=(x_{1},x_{2},x_{3},x_{4})\in R^{4}|x_{1}+x_{2}+x_{4}=0\} is a subspace of R^{4} v=(2,0,0,1)\in R^{4} find u_{0}\in U so ||u_{0}-v||<||u-v|| how i tried: U=sp\{(-1,1,0,0),(-1,0,0,1),(0,0,1,0)\} i know that the only u_{0} for which this innequality will work is if it will be the...
  18. N

    7 projection on a different axes question

    7) T:R^{2}->R^{2} projection transformation on X-axes parallel to the line y=-\sqrt{3}x find the representative matrices of T{*} by B=\{(1,0),(0,1)\} basis how i tried: i understood that the x axes stayed the same but the y axes turned into y=-\sqrt{3}x our T takes some vector and...
  19. T

    Solve du/dt=Pu when P is a projection

    Homework Statement Solve du/dt=Pu when P is a projection. [1/2 1/2 = du/dt with 1/2 1/2] [5 = u(0). 3] Part of u(0) increases exponentially while the nullspace part stays fixed. Homework Equations du/dt = Au with u=u(0) at t=0 The Attempt at a...
  20. L

    Linear Algebra Plane Projection

    Homework Statement Let 2 be the plane containing the line, l:(x,y,z)= t(6,4,2)+ (3,-4,2) and the point Q(5, -7, 7). Let P be the point (-6, -12,5) a) Find the projection of QP onto 2. Homework Equations I know the projection eqn would be (( plane 2 dot QP)/ magnitude on QP) * components...
  21. G

    Linear Algebra/Standard matrix of a projection onto a plane

    Homework Statement Let u=(-1,-2,-2,2) and v=(-1,-2,-2,-1) and let V=span{u,v}. (Just to be clear, u and v are column vectors) Find the standard matrix that projects points (orthogonally) onto V.Homework Equations The Attempt at a Solution I started by making a matrix A=[u,v], which...
  22. T

    Projection onto the kernel of a matrix

    If we have a matrix M with a kernel, in many cases there exists a projection operator P onto the kernel of M satisfying [P,M]=0. It seems to me that this projector does not in general need to be an orthogonal projector, but it is probably unique if it exists. My question: is there a standard...
  23. H

    Graph of a function only if first projection is bijective

    Homework Statement If A and B are sets, prove that a subset \Gamma\subset A X B is the graph of some function from A to B if and only if the first projection \rho: \Gamma\rightarrow A is a bijection. Homework Equations The Attempt at a Solution I first thought that i should...
  24. F

    Parallelograms projection on a plain

    Homework Statement Parallelograms 5cm side is located on a plain alpha and its 3cm side forms an angle with the plain equal to 30 degrees. Find the area for the parallelograms projection on the plain alpha, if an angle in the original parallelogram is 60 degrees. Homework Equations all...
  25. L

    Susy transforrnations & gso projection

    I'm a little confused about the relaionship between susy transformations involving Q generators & gso projection in superstring theory. If gso projection is used in RNS sectors, does that only eliminate certain states, such as tachyon, then susy must still be applied? Or does gso projection...
  26. M

    Solving the Electron Projection Problem with Field E

    ok i have a problem to work on in my new course, and i was wondering what i need to do to tackle it. the question is as follows: An electron is projected with an initial velocity Vo=10^7m/s into the uniform field between the parallel plates "E". the direction of the field is vertically...
  27. O

    Simple Vector Component Projection

    Homework Statement Consider the two vectors A=ai and B=3i+4j. What must be the value of a if the component of A along B is 6? Homework Equations The Attempt at a Solution I've arrived at the correct answer by finding the angle between the x component of B (3) and B itself which...
  28. F

    Find vectors that produce certain orthogonal projection

    I have vector [ tex ] v [ /tex ] produced by an orthogonal projection of vector [ tex ] w [ /tex ] over plane spanned by vectors [ tex ] u_1 [ /tex ] and [ tex ] u_2 [ /tex ], in a three dimensional space. If I know [ tex ] v [ /tex ], [ tex ] u_1 [ /tex ] and [ tex ] u_2 [ /tex ], how could I...
  29. H

    Hurricane path projection and mathematics

    I imagine differential equations and statistics are used. What type of math is used to predict the path of hurricanes?
  30. E

    Parallel Projection of 3-space unto a plane at c.

    EDIT: I am looking for a correction in my understanding of relativity. A model of the universe as it appears to a photon will be presented in a LOGICALLY RIGOROUS MANNER based on my understanding of physics by examining the limiting effect as one approaches the speed of light. Since my...
  31. J

    What is the best method for projecting 3D graphics?

    When it comes to graphics (what I have learned) is that what you see on the screen is data placed in a memory (video buffer) and then the data or pixel is then plotted onto the screen. So when you manipulate the data in the video buffer you will also manipulate the pixels on the screen. Then...
  32. J

    Find the projection of W onto v for

    Homework Statement the given vector v and subspace W. (a) Let W be the subspace with basis {(1 1 0 1)T, (0 1 1 0)T, (-1 0 0 1)T} and v = (2 1 4 0)T. Homework Equations ProjWv = (<W, v> / <W, W>) * W The Attempt at a Solution So I'm trying to wrap my head around this...
  33. C

    Projecting 3-Sphere onto a Plane | Stereographic Projection

    Hello, Is it possible to project a hypersphere (a 3-sphere) onto a plane? is this possible using stereographic projection? Please, if this is possible I would appreciate a nice explain me about how to do it. Thank you! Carol
  34. M

    How do you find the vector projection p of x onto y?

    Given x=(2,-5,4)^T and y=(1,2,-1)^T
  35. A

    Why Rank is the Trace of a Projection

    Why is the Trace of a projection is its Rank. Thank you
  36. C

    Sphere Projection: Clarification Needed

    Hello, I was wondering if anyboday can clarify this for me. I am trying to project a sphere into a plane, I am using the stereogriphic projection which I believe in cartesian coordinates is: x'=x/(R^2-z) y'=y/(R^2-z) where x' and y' are the coordinates in the plane, (x,y,z) the...
  37. C

    What is the Projection of Line M_1P on Plane \pi?

    Homework Statement Given \pi: \begin{cases}l_1: \frac{x-2}{4}\ = \frac{y-1}{2}\ = \frac{z+5}{-4} &\\l_2: \frac{x+4}{-2}\ = \frac{y+1}{0}\ = \frac{z}{1} & \end{cases} and the point M=(1,2,3) outside the plane. Find the projection of the line M_1P on plane \pi where P is the intersection point...
  38. H

    Why escape velocity is independent of angle of projection

    can someone explain physically why escape velocity is independent of angle of projection.
  39. D

    Minimization Problem (using Projection)

    Homework Statement Minimize ||cos(2x) - f(x)|| where f(x) is a a function in the span of {(1,sin(x),cos(x)} Where the inner produect is defined (1/pi)(integral from -pi to pi of f(x)g(x) dx) Homework Equations I found f(x) to be zero. Is this correct I am uneasy about this...
  40. Y

    Sequence of projection is Cauchy

    Homework Statement Let {M_i} be an orthogonal sequence of complete subspaces of a pre-Hilbert space V, and let P_i be the orthogonal projection on M_i. Prove that {P_i(e)} is Cauchy for any e in V 2. The attempt at a solution I'm trying to prove as n and m goes infinity...
  41. C

    Gamma matrices and projection operator question on different representations

    Typically I understand that projection operators are defined as P_-=\frac{1}{2}(1-\gamma^5) P_+=\frac{1}{2}(1+\gamma^5) where typically also the fifth gamma matrices are defined as \gamma^5=i\gamma^0\gamma^1\gamma^2\gamma^3 and.. as we choose different representations the projection...
  42. C

    Gamma matrices projection operator

    Typically I understand that projection operators are defined as P_-=\frac{1}{2}(1-\gamma^5) P_+=\frac{1}{2}(1+\gamma^5) where typically also the fifth gamma matrices are defined as \gamma^5=i\gamma^0\gamma^1\gamma^2\gamma^3 and.. as we choose different representations the projection...
  43. M

    Calculating Vector & Scalar Projection of a & b

    Homework Statement i have to find the scalar and vector projection of a=i-j+k and b=2i-j-2k and i got: Vector proj = (1/3)(i-j+k) = i/3 + j/3 + k/3 scalar proj = (1/9)(2i-j-2k) = 2i/9 - j/9 - 2k/9 is this correct?
  44. M

    Matrix of orthogonal projection

    Homework Statement Let A be the matrix of an orthogonal projection. Find A^2 in two ways: a. Geometrically. (consider what happens when you apply an orthogonal projection twice) b. By computation, using the formula: matrix of orthogonal projection onto V = QQ^T, where Q = [u1 ... um]...
  45. K

    Is this Operator a Projection Operator? A Proof

    Hi, I'm having trouble proving that a particular operator is a projection operator. If you could take a look at the attached document, that contains my question I'd be really grateful!
  46. C

    Projectile Motion (Angles of projection problem)

    Homework Statement The fireman wishes to direct the flow of water from his hose to the fire at B. Determine two possible angles θ1 and θ2 at which this can be done. Water flows from the hose at v = 55 ft/s. There is no air friction. Homework Equations v = v0 + at x = x0 + vt v2 = v^{2}_{0}...
  47. P

    Calculating Body Projection: Time, Height & Range

    A body is projected from ground level with a speed of 24 m/s at an angle of 30 degrees above the horizontal. Neglect air resistance and take gravity to be 10 m/s. Calculate: a) The time taken to reach its highest point b) The greatest height reached c) The horizontal range of the body a)...
  48. Fredrik

    Functional analysis, projection operators

    Homework Statement I want to understand the proof of proposition 7.1 in Conway. The theorem says that if \{P_i|i\in I\} is a family of projection operators, and P_i is orthogonal to P_j when i\neq j, then for any x in a Hilbert space H, \sum_{i\in I}P_ix=Px where P is the projection...
  49. A

    Q. How can I solve this kinematics and projection problem?

    Homework Statement Hi I have been stumped by this question for the past few days. Worrying since I will be sitting STEP in June! Never mind. It goes like this: A particle is projected vertically upwards with a speed of 30m/s from a point A. The point B is h metres above A. The particle moves...
  50. A

    Angle of Projection from Height and Range

    Homework Statement A projectile is fired in such a way that that its horizontal range is three times its maximum height. What is the angle of projection? Homework Equations R = Vo2sin(2theta)/g H = (Vosin(theta)2/2g R = 3H Cancel Voo, g and sin(theta) to leave 4/3 tan(theta) =...
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