spectral decomposition of a matrix calculator

As we saw above, BTX = 0. \begin{array}{cc} Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. View history. \]. \begin{array}{cc} The Eigenvectors of the Covariance Matrix Method. The determinant in this example is given above.Oct 13, 2016. Hermitian matrices have some pleasing properties, which can be used to prove a spectral theorem. Each $P_i$ is calculated from $v_iv_i^T$. Tutorial on spectral decomposition theorem and the concepts of algebraic multiplicity. Spectral decomposition calculator - To improve this 'Singular Value Decomposition Calculator', please fill in questionnaire. De nition 2.1. determines the temperature, pressure and gas concentrations at each height in the atmosphere. \langle v, Av \rangle = \langle v, \lambda v \rangle = \bar{\lambda} \langle v, v \rangle = \bar{\lambda} This method decomposes a square matrix, A, into the product of three matrices: \[ We use cookies to improve your experience on our site and to show you relevant advertising. \end{array} U columns contain eigenvectors of matrix MM; -is a diagonal matrix containing singular (eigen)values What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? Are your eigenvectors normed, ie have length of one? -1 & 1 Q = By taking the A matrix=[4 2 -1 \end{array} \right) Let, 1.6 limits and continuity homework flamingo math, Extra questions on algebraic expressions and identities for class 8, Height of a triangle calculator with area, How to calculate profit margin percentage, How to do quick decimal math without a calculator, How to find square root easily without calculator, Linear equation solver 3 unknowns in fractions, What is the missing statement and the missing reason in step 5. To embed a widget in your blog's sidebar, install the Wolfram|Alpha Widget Sidebar Plugin, and copy and paste the Widget ID below into the "id" field: We appreciate your interest in Wolfram|Alpha and will be in touch soon. \underset{n\times n}{\mathbf{A}} = \underset{n\times n}{\mathbf{P}}~ \underset{n\times n}{\mathbf{D}}~ \underset{n\times n}{\mathbf{P}^{\intercal}} The following theorem is a straightforward consequence of Schurs theorem. 1 & -1 \\ $$\mathsf{A} = \mathsf{Q\Lambda}\mathsf{Q}^{-1}$$. By Property 9 of Eigenvalues and Eigenvectors we know that B-1AB and A have the same eigenvalues, and in fact, they have the same characteristic polynomial. Is it possible to rotate a window 90 degrees if it has the same length and width? 3 & 0\\ Since the columns of B along with X are orthogonal, XTBj= X Bj = 0 for any column Bj in B, and so XTB = 0, as well as BTX = (XTB)T = 0. \begin{split} The objective is not to give a complete and rigorous treatment of the subject, but rather show the main ingredientes, some examples and applications. Leave extra cells empty to enter non-square matrices. \begin{array}{cc} , | With help of this calculator you can: find the matrix determinant, the rank, raise the matrix to a power, find the sum and the multiplication of matrices, calculate the inverse matrix. order now To see this let \(A\in M_n(\mathbb{R}) \subset M_n(\mathbb{C})\) be a symmetric matrix with eigenvalue \(\lambda\) and corresponding eigenvector \(v\). = \end{array} Thank you very much. A=QQ-1. The Singular Value Decomposition (SVD) of a matrix is a factorization of that matrix into three matrices. And now, matrix decomposition has become a core technology in machine learning, largely due to the development of the back propagation algorithm in tting a neural network. \end{array} \left\{ A scalar \(\lambda\in\mathbb{C}\) is an eigenvalue for \(A\) if there exists a non-zero vector \(v\in \mathbb{R}^n\) such that \(Av = \lambda v\). Real Statistics Function: The Real Statistics Resource Pack provides the following function: SPECTRAL(R1,iter): returns a 2n nrange whose top half is the matrixCand whose lower half is the matrixDin the spectral decomposition of CDCTofAwhereAis the matrix of values inrange R1. The result is trivial for . 1 & 2 \\ = \langle v_1, \lambda_2 v_2 \rangle = \bar{\lambda}_2 \langle v_1, v_2 \rangle = \lambda_2 \langle v_1, v_2 \rangle For spectral decomposition As given at Figure 1 1 & - 1 \\ Do you want to find the exponential of this matrix ? , The next column of L is chosen from B. Better than just an app, Better provides a suite of tools to help you manage your life and get more done. We can use spectral decomposition to more easily solve systems of equations. has the same size as A and contains the singular values of A as its diagonal entries. With Instant Expert Tutoring, you can get help from a tutor anytime, anywhere. 3 & 0\\ Using the Spectral Theorem, we write A in terms of eigenvalues and orthogonal projections onto eigenspaces. In this context, principal component analysis just translates to reducing the dimensionality by projecting onto a subspace generated by a subset of eigenvectors of \(A\). Spectral decomposition is any of several things: Spectral decomposition for matrix: eigendecomposition of a matrix. If not, there is something else wrong. -3 & 4 \\ So the effect of on is to stretch the vector by and to rotate it to the new orientation . P_{u}:=\frac{1}{\|u\|^2}\langle u, \cdot \rangle u : \mathbb{R}^n \longrightarrow \{\alpha u\: | \: \alpha\in\mathbb{R}\} This shows that the number of independent eigenvectors corresponding to is at least equal to the multiplicity of . We assume that it is true for anynnsymmetric matrix and show that it is true for ann+1 n+1 symmetric matrixA. The values of that satisfy the equation are the eigenvalues. \]. Free Matrix Diagonalization calculator - diagonalize matrices step-by-step. Once you have determined what the problem is, you can begin to work on finding the solution. A + I = \], \(\lambda_1, \lambda_2, \cdots, \lambda_k\), \(P(\lambda_i):\mathbb{R}^n\longrightarrow E(\lambda_i)\), \(\mathbb{R}^n = \bigoplus_{i=1}^{k} E(\lambda_i)\), \(B(\lambda_i) := \bigoplus_{i\neq j}^{k} E(\lambda_i)\), \(P(\lambda_i)P(\lambda_j)=\delta_{ij}P(\lambda_i)\), \(A = \sum_{i=i}^{k} \lambda_i P(\lambda_i)\), \[ Proof: Suppose 1 is an eigenvalue of the n n matrix A and that B1, , Bk are k independent eigenvectors corresponding to 1. We now show that C is orthogonal. Mathematics is the study of numbers, shapes, and patterns. (\mathbf{X}^{\intercal}\mathbf{X})\mathbf{b} = \mathbf{X}^{\intercal}\mathbf{y} Hi Charles, is there any procedure to compute eigen values and vectors manually in Excel? Now define B to be the matrix whose columns are the vectors in this basis excluding X. This completes the verification of the spectral theorem in this simple example. \end{array} \left( \begin{array}{cc} Now let B be the n n matrix whose columns are B1, ,Bn. 3 LU decomposition Cholesky decomposition = Display decimals Clean + With help of this calculator you can: find the matrix determinant, the rank, raise the matrix to a power, find the sum and the multiplication of matrices, calculate the inverse matrix. \right) . The procedure to use the eigenvalue calculator is as follows: Step 1: Enter the 22 or 33 matrix elements in the respective input field. Let us consider a non-zero vector \(u\in\mathbb{R}\). The method of finding the eigenvalues of an n*n matrix can be summarized into two steps. symmetric matrix So i am assuming that i must find the evalues and evectors of this matrix first, and that is exactly what i did. 0 & 0 \\ 0 \end{array} \right] = Nice app must try in exams times, amazing for any questions you have for math honestly good for any situation I'm very satisfied with this app it can do almost anything there are some things that can't do like finding the polynomial multiplication. \det(B -\lambda I) = (1 - \lambda)^2 Thus, in order to find eigenvalues we need to calculate roots of the characteristic polynomial \(\det (A - \lambda I)=0\). Real Statistics Data Analysis Tool: The Spectral Factorization option of the Real Statistics Matrix Operations data analysis tool also provides the means to output the spectral decomposition of a symmetric matrix. Matrix is a diagonal matrix . And your eigenvalues are correct. \left( The matrix \(Q\) is constructed by stacking the normalized orthogonal eigenvectors of \(A\) as column vectors. % This is my filter x [n]. Checking calculations. Moreover, we can define an isometry S: r a n g e ( | T |) r a n g e ( T) by setting (11.6.3) S ( | T | v) = T v. The trick is now to define a unitary operator U on all of V such that the restriction of U onto the range of | T | is S, i.e., In linear algebra, eigendecomposition is the factorization of a matrix into a canonical form, whereby the matrix is represented in terms of its eigenvalues and eigenvectors.Only diagonalizable matrices can be factorized in this way. If you're looking for help with arithmetic, there are plenty of online resources available to help you out. Spectral Decomposition Theorem 1 (Spectral Decomposition): Let A be a symmetric nn matrix, then A has a spectral decomposition A = CDCT where C is an nn matrix whose columns are unit eigenvectors C1, , Cn corresponding to the eigenvalues 1, , n of A and D is the nn diagonal matrix whose main diagonal consists of 1, , n. 1 & -1 \\ Learn more about Stack Overflow the company, and our products. 1 & 1 \\ We can read this first statement as follows: The basis above can chosen to be orthonormal using the. 1 & 1 1 & 1 \\ \right) For d. let us simply compute \(P(\lambda_1 = 3) + P(\lambda_2 = -1)\), \[ \left( Matrix Spectrum The eigenvalues of a matrix are called its spectrum, and are denoted . \mathbf{P} &= \begin{bmatrix}\frac{5}{\sqrt{41}} & \frac{1}{\sqrt{2}} \\ -\frac{4}{\sqrt{41}} & \frac{1}{\sqrt{2}}\end{bmatrix} \\[2ex] \frac{1}{2} A= \begin{pmatrix} -3 & 4\\ 4 & 3 \begin{pmatrix} 2 \sqrt{5}/5 & \sqrt{5}/5 \\ \sqrt{5}/5 & -2 \sqrt{5}/5 The transformed results include tuning cubes and a variety of discrete common frequency cubes. This decomposition only applies to numerical square . \left( To subscribe to this RSS feed, copy and paste this URL into your RSS reader. \left( Math Index SOLVE NOW . LU DecompositionNew Eigenvalues Eigenvectors Diagonalization Matrix Eigenvalues calculator - Online Matrix Eigenvalues calculator that will find solution, step-by-step online. 2 & 1 \[ I think of the spectral decomposition as writing $A$ as the sum of two matrices, each having rank 1. The eigenvalue problem is to determine the solution to the equation Av = v, where A is an n-by-n matrix, v is a column vector of length n, and is a scalar. $\begin{bmatrix} 1 & -2\end{bmatrix}^T$ is not an eigenvector too. You can try with any coefficients, it doesn't matter x = dfilt.dffir (q_k + 1/ (10^ (SNR_MFB/10))); % Here I find its zeros zeros_x = zpk (x); % And now I identify those who are inside and outside the unit circle zeros_min = zeros_x . Spectral Factorization using Matlab. This was amazing, math app has been a lifesaver for me, it makes it possible to check their work but also to show them how to work a problem, 2nd you can also write the problem and you can also understand the solution. We can rewrite the eigenvalue equation as (A I)v = 0, where I Mn(R) denotes the identity matrix. where, P is a n-dimensional square matrix whose ith column is the ith eigenvector of A, and D is a n-dimensional diagonal matrix whose diagonal elements are composed of the eigenvalues of A. Note that by Property 5 of Orthogonal Vectors and MatricesQ is orthogonal. \], \[ The proof of singular value decomposition follows by applying spectral decomposition on matrices MMT and MT M. \right) = You can use the approach described at How do you get out of a corner when plotting yourself into a corner. P^2_u(v) = \frac{1}{\|u\|^4}\langle u, \langle u , v \rangle u \rangle u = \frac{1}{\|u\|^2}\langle u, v \rangle u = P_u(v) \lambda = \lambda \langle v, v \rangle = \langle \lambda v, v \rangle = \langle Av, v \rangle = \langle v, A^T v \rangle = \left( It is used in everyday life, from counting to measuring to more complex calculations. \begin{array}{cc} The eigenvectors were outputted as columns in a matrix, so, the $vector output from the function is, in fact, outputting the matrix P. The eigen() function is actually carrying out the spectral decomposition! 1 & 1 \end{array} Now we can carry out the matrix algebra to compute b. import numpy as np from numpy import linalg as lg Eigenvalues, Eigenvectors = lg.eigh (np.array ( [ [1, 3], [2, 5] ])) Lambda = np.diag . You should write $A$ as $QDQ^T$ if $Q$ is orthogonal. 1 & -1 \\ By browsing this website, you agree to our use of cookies. To embed this widget in a post on your WordPress blog, copy and paste the shortcode below into the HTML source: To add a widget to a MediaWiki site, the wiki must have the. 1 & 2\\ You need to highlight the range E4:G7 insert the formula =eVECTORS(A4:C6) and then press Ctrl-Shift-Enter. \begin{array}{cc} Spectral decomposition (a.k.a., eigen decomposition) is used primarily in principal components analysis (PCA). You can use math to determine all sorts of things, like how much money you'll need to save for a rainy day. Learn more about Stack Overflow the company, and our products. Follow Up: struct sockaddr storage initialization by network format-string. If an internal . Find more . \right \} \left( Linear Algebra, Friedberg, Insel and Spence, Perturbation Theory for Linear Operators, Kato, \(A\in M_n(\mathbb{R}) \subset M_n(\mathbb{C})\), \[ Timely delivery is important for many businesses and organizations. for R, I am using eigen to find the matrix of vectors but the output just looks wrong. | But as we observed in Symmetric Matrices, not all symmetric matrices have distinct eigenvalues. Matrix Eigen Value & Eigen Vector for Symmetric Matrix Let us compute and factorize the characteristic polynomial to find the eigenvalues: \[ \], \[ By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This representation turns out to be enormously useful. Given an observation matrix \(X\in M_{n\times p}(\mathbb{R})\), the covariance matrix \(A:= X^T X \in M_p(\mathbb{R})\) is clearly symmetric and therefore diagonalizable. The Spectral Theorem A (real) matrix is orthogonally diagonalizable88 E if and only if E is symmetric. 1 & - 1 \\ If it is diagonal, you have to norm them. 1\\ \left( \begin{bmatrix} -3 & 4 \\ 4 & 3\end{bmatrix}\begin{bmatrix} 1 \\ 2\end{bmatrix}= 5 \begin{bmatrix} 1 \\ 2\end{bmatrix} \end{array} \right) Tapan. \left( \left( Finally since Q is orthogonal, QTQ = I. Matrix decompositions are a collection of specific transformations or factorizations of matrices into a specific desired form. To use our calculator: 1. \end{pmatrix} Most methods are efficient for bigger matrices. A = \lambda_1P_1 + \lambda_2P_2 Step 3: Finally, the eigenvalues or eigenvectors of the matrix will be displayed in the new window. E(\lambda = 1) = is an 1\\ It only takes a minute to sign up. Why do small African island nations perform better than African continental nations, considering democracy and human development? \right) Step 2: Now click the button "Calculate Eigenvalues " or "Calculate Eigenvectors" to get the result. \left( Purpose of use. . \end{array} \right) By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Proposition1.3 istheonlyeigenvalueofAj Kr,and, isnotaneigenvalueofAj Y. Get Assignment is an online academic writing service that can help you with all your writing needs. \lambda_1\langle v_1, v_2 \rangle = \langle \lambda_1 v_1, v_2 \rangle = \langle A v_1, v_2 \rangle = \langle v_1, A v_2 \rangle Quantum Mechanics, Fourier Decomposition, Signal Processing, ). A = \left ( \right) We need to multiply row by and subtract from row to eliminate the first entry in row , and then multiply row by and subtract from row . \left( Since. Orthonormal matrices have the property that their transposed matrix is the inverse matrix. Let us now see what effect the deformation gradient has when it is applied to the eigenvector . . The Schur decomposition of a square matrix M M is its writing in the following form (also called Schur form): M =Q.T.Q1 M = Q. T. Q 1. with Q Q a unitary matrix (such as Q.Q=I Q . Most people would think that this app helps students cheat in math, but it is actually quiet helpfull. Obviously they need to add more ways to solve certain problems but for the most part it is perfect, this is an amazing app it helps so much and I also like the function for when you get to take a picture its really helpful and it will make it much more faster than writing the question. Bulk update symbol size units from mm to map units in rule-based symbology, The difference between the phonemes /p/ and /b/ in Japanese. \] Note that: \[ $$ \lambda_1 &= -7 \qquad &\mathbf{e}_1 = \begin{bmatrix}\frac{5}{\sqrt{41}} \\ -\frac{4}{\sqrt{41}}\end{bmatrix}\\[2ex] First, find the determinant of the left-hand side of the characteristic equation A-I. \left\{ \left[ \begin{array}{cc} 1 & 1 Has saved my stupid self a million times. You are doing a great job sir. By Property 3 of Linear Independent Vectors, we can construct a basis for the set of all n+1 1 column vectors which includes X, and so using Theorem 1 of Orthogonal Vectors and Matrices (Gram-Schmidt), we can construct an orthonormal basis for the set of n+1 1 column vectors which includes X. \[ \right) and also gives you feedback on https://real-statistics.com/matrices-and-iterative-procedures/goal-seeking-and-solver/ Then L and B = A L L T are updated. \frac{1}{\sqrt{2}} Theorem 1(Spectral Decomposition): LetAbe a symmetricnnmatrix, thenAhas a spectral decompositionA = CDCTwhereC is annnmatrix whose columns are unit eigenvectorsC1, ,Cncorresponding to the eigenvalues1, ,nofAandD is thenndiagonal matrix whose main diagonal consists of1, ,n. orthogonal matrix In this case, it is more efficient to decompose . A1 = L [1] * V [,1] %*% t(V [,1]) A1 ## [,1] [,2] [,3] ## [1,] 9.444 -7.556 3.778 ## [2,] -7.556 6.044 -3.022 ## [3,] 3.778 -3.022 1.511 Just type matrix elements and click the button. \right) There must be a decomposition $B=VDV^T$. \begin{array}{cc} To embed this widget in a post, install the Wolfram|Alpha Widget Shortcode Plugin and copy and paste the shortcode above into the HTML source. The spectral decomposition recasts a matrix in terms of its eigenvalues and eigenvectors. \begin{array}{cc} The spectral decomposition is the decomposition of a symmetric matrix A into QDQ^T, where Q is an orthogonal matrix and D is a diagonal matrix. The evalues are $5$ and $-5$, and the evectors are $(2,1)^T$ and $(1,-2)^T$, Now the spectral decomposition of $A$ is equal to $(Q^{-1})^\ast$ (diagonal matrix with corresponding eigenvalues) * Q, $Q$ is given by [evector1/||evector1|| , evector2/||evector2||], $$ Let rdenote the number of nonzero singular values of A, or equivalently the rank of A. In other words, we can compute the closest vector by solving a system of linear equations. \left( \mathbf{PDP}^{\intercal}\mathbf{b} = \mathbf{X}^{\intercal}\mathbf{y} Assume \(||v|| = 1\), then. \begin{bmatrix} -3 & 4 \\ 4 & 3\end{bmatrix}\begin{bmatrix} -2 \\ 1\end{bmatrix}= -5 \begin{bmatrix} -2 \\ 1\end{bmatrix} Let us compute the orthogonal projections onto the eigenspaces of the matrix, \[ \left( Math is a subject that can be difficult to understand, but with practice and patience, anyone can learn to figure out math problems. rev2023.3.3.43278. Example 1: Find the spectral decomposition of the matrix A in range A4:C6 of Figure 1. \left( What is the correct way to screw wall and ceiling drywalls? Remark: When we say that there exists an orthonormal basis of \(\mathbb{R}^n\) such that \(A\) is upper-triangular, we see \(A:\mathbb{R}^n\longrightarrow \mathbb{R}^n\) as a linear transformation. Eigendecomposition makes me wonder in numpy. -1 & 1 \text{span} In practice, to compute the exponential we can use the relation A = \(Q D Q^{-1}\), \[ Proof: I By induction on n. Assume theorem true for 1. This property is very important. Let \(A\in M_n(\mathbb{R})\) be an \(n\)-dimensional matrix with real entries. L = [ a 0 0 d e 0 g h i] L = Lower Triangular Matrix. Age Under 20 years old 20 years old level 30 years old . Display decimals , Leave extra cells empty to enter non-square matrices. . Where does this (supposedly) Gibson quote come from? \right) Now the way I am tackling this is to set V to be an n x n matrix consisting of the eigenvectors in columns corresponding to the positions of the eigenvalues i will set along the diagonal of D. What is SVD of a symmetric matrix? The condition \(\text{ran}(P_u)^\perp = \ker(P_u)\) is trivially satisfied. We denote by \(E(\lambda)\) the subspace generated by all the eigenvectors of associated to \(\lambda\). We next show that QTAQ = E. Next we need to show that QTAX = XTAQ = 0. There is nothing more satisfying than finally getting that passing grade. , Figure 7.3 displays the block diagram of a one-dimensional subband encoder/decoder or codec. of a real $$ \[ Solving for b, we find: \[ \], \[ \left( \left( \], \[ Charles, Thanks a lot sir for your help regarding my problem. Can you print $V\cdot V^T$ and look at it? Namely, \(\mathbf{D}^{-1}\) is also diagonal with elements on the diagonal equal to \(\frac{1}{\lambda_i}\). \[ \]. Charles. \begin{array}{cc} where \(D\) is a diagonal matrix containing the eigenvalues in \(A\) (with multiplicity). 4 & 3\\ Now define the n+1 n matrix Q = BP. \end{bmatrix} \big(\mathbf{PDP}^{\intercal}\big)^{-1}\mathbf{PDP}^{\intercal}\mathbf{b} &= \big(\mathbf{PDP}^{\intercal}\big)^{-1} \mathbf{X}^{\intercal}\mathbf{y} \\[2ex] 1 & 2\\ In terms of the spectral decomposition of we have. Note that at each stage of the induction, the next item on the main diagonal matrix of D is an eigenvalue of A and the next column in C is the corresponding eigenvector and that this eigenvector is orthogonal to all the other columns in C. Observation: The spectral decomposition can also be expressed as A = . It now follows that the first k columns of B1AB consist of the vectors of the form D1, ,Dkwhere Dj consists of 1 in row j and zeros elsewhere. The interactive program below yield three matrices Did i take the proper steps to get the right answer, did i make a mistake somewhere? Hence, computing eigenvectors is equivalent to find elements in the kernel of \(A - \lambda I\). Proof. \text{span} \right) The problem I am running into is that V is not orthogonal, ie $V*V^T$ does not equal the identity matrix( I am doing all of this in $R$). 2 De nition of singular value decomposition Let Abe an m nmatrix with singular values 1 2 n 0. is also called spectral decomposition, or Schur Decomposition. Remark: The CayleyHamilton theorem says that every square matrix (over a commutative ring) satisfies its own characteristic polynomial. Spectral decompositions of deformation gradient. \[ Decomposition of spectrum (functional analysis) This disambiguation page lists articles associated with the title Spectral decomposition. -2 & 2\\ To adjust a gas concentration, choose a scale factor other than 1 (from 0 to 1000). \end{array} the multiplicity of B1AB, and therefore A, is at least k. Property 2: For each eigenvalue of a symmetric matrix there are k independent (real) eigenvectors where k equals the multiplicity of , and there are no more than k such eigenvectors. \begin{split} linear-algebra matrices eigenvalues-eigenvectors. \right) The difference between the phonemes /p/ and /b/ in Japanese, Replacing broken pins/legs on a DIP IC package. Math app is the best math solving application, and I have the grades to prove it. 2 & 1 Course Index Row Reduction for a System of Two Linear Equations Solving a 2x2 SLE Using a Matrix Inverse Solving a SLE in 3 Variables with Row Operations 1 and since \(D\) is diagonal then \(e^{D}\) is just again a diagonal matrix with entries \(e^{\lambda_i}\). \left( \text{span} 1 & -1 \\ Theoretically Correct vs Practical Notation. Matrix Algebra Tutorials-http://goo.gl/4gvpeCMy Casio Scientific Calculator Tutorials-http://goo.gl/uiTDQSOrthogonal Diagonalization of Symmetric Matrix vide. An important result of linear algebra, called the spectral theorem, or symmetric eigenvalue decomposition (SED) theorem, states that for any symmetric matrix, there are exactly (possibly not distinct) eigenvalues, and they are all real; further, that the associated eigenvectors can be chosen so as to form an orthonormal basis. when i am trying to find Eigen value and corresponding Eigen Vector by using eVECTORS(A). \begin{split} \det(B -\lambda I) = (1 - \lambda)^2 \] \end{array} \end{array} \begin{array}{cc} Thanks to our quick delivery, you'll never have to worry about being late for an important event again!

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