Full rank matrix invertible - 6) There is a square matrix B with AB = I and BA = I.

 
<b>Matrix</b> or vector norm. . Full rank matrix invertible

Nov 06, 2022 · Full column rank - an overview. Proof: The matrix is full column rank if and only if its nullspace if reduced to the singleton , that is, If is invertible, then indeed the condition implies , which in turn implies. (b) Prove that the linear system with matrix of coefficients A has a solution for dn's on the right side if and only if. The matrix is invertible; In full column rank matrices, or r = n < m. Share Cite Follow. 17464352 0. This common quantity is called the rank of A. a: Instituto de Ciencias Aplicadas y Tecnología, UNAM. For an r x c matrix, If r is less than c, then the maximum rank of the matrix is r. So, with G [3 13 and F = 2 9], we have A = FG, a full rank factorization. There is an infinite amount of solutions to every b. A is invertible Explain this: If A is of full rank, then At. Consider the following 2-by-2 matrix: The matrix is invertible. Numer-ical example is presented in Sect. If you leave B unspecified, it is default to a diagonal matrix hence you will be explicitly computing matrix inverse of A. When the rank equals the smallest dimension it is called "full rank", a smaller rank is called "rank deficient". bizzare hardcore fucking movies; edf geo smart meter; az photoresist data sheet; Culture how to add new column in dbeaver. Second, for a square and invertible matrix A,theinverseofA is VD−1UT. In addition, we have another concept that’s called a Null space of a matrix \ (A \). The null space of A is {0}. The columns of form a linearly independent set. Suppose that the columns of M are v1,,vn, and that they're linearly dependent. 13 Rank of a Matrix—Some Preliminary Results 82. 12 The Inverse of a Matrix 80. Follow the following steps to complete the procedure of calculating rank of matrix online. for some invertible matrix U by Theorem 2. Any square matrix A over a field R is invertible if and only if any of the following equivalent conditions (and hence, all) hold true. The matrix A has n non-zero singular values. In this case, we find that the det(A) = −18, so A is full rank, . Invertibility of matrices over a division ring can also be. This algorithm runs in O (n*m^2). The maximum number of . Consider the system of linear equations I 2 + 2x3 -1 21 + X2 5 -21 X2 + + 3x4 1 21 + 2x2 + 9 (a) (10 marks) Use hand calculations to find the LU decomposition of the coefficient matrix A and then solve the resulting triangular system. Computer Science. Since is full column rank, we obtain , as desired. It's only true if A is a square matrix. Find an invertible matrix P and a matrix C of the form + V₁ = -5- 1 O B. To estimate a low rank matrix from noisy observations, truncated singular value decomposition has been extensively used and studied: empirical singular values are hard thresholded and. Rank of a block of an invertible matrix. Therefore, matrix A does not have an inverse, which means that matrix A is . A matrix is invertible if any of the following equivalent conditions hold Its determinant is nonzero All of its eigenvalues are nonzero The nullspace is trivial (composed of only the zero object) It is of full rank (Its rank equals its dimension) In practice you try to tell what type of matrix it is. Just a. The inputs for this method are the incident fields and a library matrix that contains the RF field response of every edge an implant can occupy. There exist at least one minor of order 'r' that is non-zero. This generalizes the results of Vaserstein and Wheland on rings having stable rank one. In general, a square matrix over a commutative ring is invertible if and only if its determinant is a unit in that ring. Properties of the Rank of the Matrix: Rank linear algebra refers to finding column rank or row rank collectively known as the rank of the matrix. The null space of A is {0}. Then AB = BA = I n. The rank of a matrix is defined as the maximum number of linearly independent vectors in rows or columns. Steps for Determining if a Matrix is Invertible Step 1: Take a look at the matrix and identify its dimensions. If then has full row rank and will have dimensions , and rank , and be invertible. If A is invertible k e r ( A) = ∅ then A is full rank. Note 3. But for matrices that aren't full rank, which squish to a smaller dimension, you can have a whole bunch of vectors land on zero. The order of highest order non−zero minor is said to be the rank of a matrix. algebra offers a matrix-oriented approach with more emphasis on problem solving and applications. 16 Rank and Inverse Matrices 87. Generate a random 3 by 3 matrix A with rank 3. Full-rank square matrix in RREF is the identity matrix Let A be an n by n matrix. The following notation will be used: R - the set of real numbers, Rn×m-the set of n×m real matrices and Rn = Rn×1, C - the field of complex numbers. The Korean Business Research Institute has analyzed 68,556,547 boy group brand big data collected from March 9, <b>2022</b>, to April. What is full rank matrix example? Example: for a 2×4 matrix the rank can't be larger than 2. Thus, a necessary condition for (2) is that m p. A B = B A = I. 14 The Number of LIN Rows and Columns in a Matrix 84. If you leave B unspecified, it is default to a diagonal matrix hence you will be explicitly computing matrix inverse of A. 2 Matrices Having All Elements Equal 102. Is matrix A invertible ? Attempt to solve rank (A) = 3 det ( A) = 0 which implies matrix is not invertible. for example, when solving for If A is a square matrix of full rank, C# Program to Find the Rank of a given Array » Next Page – C# Program to Perform Matrix Addition « Best Reference Books – Formal Languages and Automata Theory. 13 Rank of a Matrix—Some Preliminary Results 82. nullity A + rank A = n. Asking it this way doesn’t require A and/or M. When a Matrix and Its Inverse Are Nonnegative. Full Rank Matrices Full Rank Matrices Theorem A matrix is full column rank if and only if is invertible. If A is full rank it is surjective (column space span Rn) and injective (x≠y Ax≠Ay) therefore it is invertible. Also, in a matrix nonsingular matrix = invertible matrix. Consider a square matrix A of size n × n, elements of which may be either real or complex numbers. In linear algebra, an n-by-n square matrix is called invertible(also nonsingular or nondegenerate), if the product of the matrix and its inverse is the . The dimension of the null space of A is 0. A matrix is said to be. You should read ?solve carefully, and possibly many times for hints. Prove that A 0 (i. ٢ شعبان ١٤٤١ هـ. Clearly this can only be the case if N≤M. Military personnel have ranks that indicate their pay grade and level of responsibility within the armed forces. Then rank(A) = n iff A has an inverse. The matrix A has n non-zero singular values. Is matrix A invertible ?. Want to see the full answer? Check out a sample Q&A here. Introduction Cosmological perturbation theory (CPT) is widely assumed to be a working model of gravity at large cosmological scales. Then A is invertible if and only if |R| = |C| and the columns of A are linearly independent. If A has rank m, then it has a right inverse: an n-by-m matrix B such that AB = I. , if and only if the design matrix has full rank (see e. 1 Symmetric Matrices 97. A non-zero matrix $A$ is said to have rank $r$ if at least one of its $r$-square minors is different from zero while every $ (r + 1)$-square minor, if any, is zero. (a) Show that a matrix can have both full row rank and full column rank only if it is square. This row is named i. 5 Special Matrices 97. The network in Fig. It is invertible if and only if the columns of the design matrix are linearly independent ---i. Keywords: Minimal semipositivity, Inverse positivity, Invertibility preservers, . The dimension of the null space of A is 0. One dimension is lost during linear. As we will prove in Chapter 15, the dimension of the column space is equal to the rank. If the matrix has an inverse, then the matrix multiplied by its inverse will give you the identity matrix. If you leave B unspecified, it is default to a diagonal matrix hence you will be explicitly computing matrix inverse of A. (b) The following equation holds (AT A+ μI)−1AT = AT (AAT +μI)−1. The noise is normally distributed with mean 0 and four. The rank of a matrix is defined as the maximum number of linearly independent vectors in rows or columns. If you leave B unspecified, it is default to a diagonal matrix hence you will be explicitly computing matrix inverse of A. A matrix is said to have full rank if its rank equals the largest possible for a matrix of the same dimensions, which is the lesser of the number of rows and columns. If A = 2 4 9 then RREF(A) = o o ]. Show that A is not invertible. 12 The Inverse of a Matrix 80. Let us check the proof of the above statement. There are, in fact, a number of equivalent conditions to the statement a matrix A is invertible det ( A) is non-zero Ax=b has only one solution Ax=0 has only the trivial solution A is full rank (there are more, here is a full list ) 4 Reply Mathuss • 5 yr. det (m) == 0 def. Search: Matrix Summation Hackerrank. Full Rank Matrices Theorem A matrix is full column rank if and only if is invertible. In general, a square matrix over a commutative ring is invertible if and only if its determinant is a unit in that ring. Request PDF | On Oct 1, 2022, Yining Wu and others published Work-in-Progress: Accelerated Matrix Factorization by Approximate Computing for Recommendation System | Find, read and cite all the. Conditions (11)–(13) involve col(A), and by the rank-nullity theorem, this is immediately teth- ered to the null space nul(A). Matrix inverse, existence of inverse, matrix inverse by Gaussian elimination. The rank of the matrix is the dimension of the vector space obtained by its columns. (a) Express J. There are, in fact, a number of equivalent conditions to the statement a matrix A is invertible det ( A) is non-zero Ax=b has only one solution Ax=0 has only the trivial solution A is full rank (there are more, here is a full list ) 4 Reply Mathuss • 5 yr. You can think of a matrix as a linear mapping and the rank of the matrix corresponds to the dimension of the image of the mapping. Matrix Rank The rank is how many of the rows are "unique": not made of other rows. , therefore, building the base from the start is. Find rank of matrix - Math Solver Online Find rank of matrix Step #1: First enter data correctly to get the output. The matrix B is called the inverse matrix of A. Full rank matrix invertible? [Expert Review] Matrix rank calculator. Start with any cell in the first row. An idempotent matrix is an orthogonal projection with each eigenvalue either 0 or 1. 2 Descriptor Continuous-Time Linear. Workplace Enterprise Fintech China Policy Newsletters Braintrust ji an love me actually instagram Events Careers minibus hire in bristol. So, we can only get an output vector that lies on this line. To compute a matrix inverse using this method, an augmented matrix is first created with the left side being the matrix to invert and the right side being the identity matrix. So A t. 41 An m×n matrix has full row rank if its row rank is m, and it has full column rank if its column rank is n. The rank is at least 1, except for a zero matrix (a matrix made of all zeros) whose rank is 0. 24 23 23 14 = 3. Describes how to find the pseudo-inverse of a matrix in Excel for matrices of full rank or not of full rank. Share Cite Follow. A real number 'r' is said to be the rank of the matrix A if it satisfies the following conditions:. Thus, a necessary condition for (2) is that m p. For A, B 2 M m ⇥ n (R) we define matrix addition as (A + B) ij = (A) ij + (B) ij and for c 2 R, scalar multiplication is defined by (cA) ij = c (A) ij 38 We normally use an uppercase letter to denote a matrix, such as A, B or C. We will add another criterium, in terms of the rank. 17 Permutation Matrices 87. 0 is not an eigenvalue of matrix A. Visiting cities hackerrank solution. If A is invertible ker(A)=∅ then A is full rank. 5 Special Matrices 97. the number of non-zero. Is matrix A invertible ?. A better way, from the standpoint of both execution time and numerical accuracy, is to use the matrix backslash operator x = A\b. (a) Show that a matrix can have both full row rank and full column rank only if it is square. Just a useless copycat. Editor’s Note: take a look at the Most Anticipated New Albums of 2022. We still have that is positive semi-definite (definite) if and only if its eigenvalues are positive (resp. The rank of the matrix is the dimension of the vector space obtained by its columns. How to solve an equation by completing the square with a negative coefficient, greatest common factor worksheets, worksheet add negative numbers, maple find the highest common factor. Introduction Cosmological perturbation theory (CPT) is widely assumed to be a working model of gravity at large cosmological scales. Try the given examples, or type in your own problem and check your answer with the. Any square matrix A over a field R is invertible if and only if any of the following equivalent conditions (and hence, all) hold true. As a special case, the complex numbers may be embedded in the normal 2×2 real matrices by the mapping a + b i ↦ [ a b − b a] = a [ 1 0 0 1] + b [ 0 1 − 1 0]. So that's a nice place to start for an invertible matrix. Determine whether a matrix is full rank. , if and only if the design matrix has full rank (see e. You can think of a matrix as a linear mapping and the rank of the matrix corresponds to the dimension of the image of the mapping. The connections that are coded in a matrix could mean many things. where ‘ In ‘ denotes the n-by-n identity matrix. Let A and B are two column vectors matrices, and P = AB T, then matrix P has rank 1. A is invertible 8. When the matrix is full rank and positive semidefinite, the matrix A becomes positive definite and. 4 Inversion of 3×3 matrices 2 Blockwise inversion 2 By Neumann series 3 Derivative of the matrix inverse 4 Moore. All functions are surjective onto their image. is of full rank. You should read ?solve carefully, and possibly many times for hints. Just a. The corresponding diagonal. sciencedirect topics. Proof: The matrix is full column rank if and only if its nullspace if reduced to the singleton , that is, If is invertible, then indeed the condition implies , which in turn implies. Share Improve this answer Follow. (We call D a right inverse of A. The 2nd reduced matrix you show above says that all three lines intersect at a single point, the origin - (0, 0). Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. ) Theorem 3. So, we can only get an output vector that lies on this line. If A is invertible ker(A)=∅ then A is full rank. 0 is not an eigenvalue of matrix A. Show that for any given matrix A ∈ Rm×n and any positive number μ : (a) Both AT A+μI and AAT +μI are invertible. Let A − 1 =: B = [ B 11 B 12 B 21 B 22] and shape of B 11 is same as A 11. FHF is an r order invertible matrix. if we have a matrix with dimensions r x c, having r number of rows and c number of columns, and if r is less than c then the rank of the matrix would be r. Step #3: Enter the values of matrix in the required tables Get Solution Mathematics: Finding Rank of Matrix Upload Your Requirement Save time Top Experts Fast solutions Matrix Rank. The rank of A is n, so an invertible matrix has full rank. If A has rank m, then it has a right inverse: an n-by-m matrix B such that AB = I. AX = 0 is a homogeneous system of n linear equations in n variables. Since G is not bipartite, there is an. A normal involution has eigenvalues ± 1. The dimension of the null space of A is 0. ٢٢ شعبان ١٤٣٨ هـ. From this definition it is obvious that the rank of a matrix cannot exceed the number of its rows (or columns). A square matrix which is not nonsingular is singular. The null space of A is {0}. Matrix inverse, existence of inverse, matrix inverse by Gaussian elimination. Step #2: Enter the dimensions of matrices. Is matrix A invertible ?. matrix is said to be invertible if and only if its columns are independent. a: Instituto de Ciencias Aplicadas y Tecnología, UNAM. We don't know anything about A. How do you. Proof: The matrix is full column rank if and only if its nullspace if reduced to the singleton , that is, If is invertible, then indeed the condition implies , which in turn implies. Let Jn be the n X :0. Simple transformations that arise in graphics such as rotation, translation, and scaling can be expressed using matrices. 4) No column in A is a scalar multiple of any other column in A. So A t. It is known that $\text{rank}(A)=3$. Jun 29, 2014 · Use M (i,j) to set every other entry of this row to zero by computing M (k) = M (k) - M (i,k)/M (i,j) * M (j) for 1 <= k <= n and k != j update the matrix with the columns computed in step 2. The orthogonal complement of the column space of A is {0}. View this solution and millions of others when you join today!. Since U is invertible, it follows that cj = a1cj1 +a2cj2 +···+arcjr and the proof is complete. ٩ رمضان ١٤٣١ هـ. $ A$ is row-equivalent to the identity matrix. The conventional factorization models are based on the assumption that the data matrices are contaminated stochastically by some type of noise. 41 An m×n matrix has full row rank if its row rank is m, and it has full column rank if its column rank is n. Image transcriptions Let‘s say that A is invertible with A = A2. Once the full data is recovered, the ISAR image can be achieved via the conventional 2D inverse fast Fourier transform. It is invertible if and only if the columns of the design matrix are linearly independent ---i. [] After multiple scattering of light in a turbid medium, a random speckle pattern is formed, which contains the information about the monochromatic light TM of the medium, and can be measured by full-field phase shift interference. 1 Symmetric Matrices 97. Share Cite Follow. The rank of A is n, so an invertible matrix has full rank. - Ben Voigt Apr 28, 2014 at 17:11 Add a comment 2 Answers. x 1 = 1 - 1 0 Let x 2 = x y z be the eigenvector corresponding to the eigenvalue λ = - 1. joel segal wedding; rooms for rent 300 a month bronx; best colleges for law enforcement and criminal justice. You won't end up at the same conclusion. For k m = 1 n and k ≠ m. jenni rivera sex tape

Moreover, Xa = 0 (and hence ||Xa|| 2 = 0) if and only if the columns of X are linearly dependent, so if X has full column rank then X'X is positive definite. . Full rank matrix invertible

All eigenvalues are different, then the <strong>matrix</strong> is diagonalizable. . Full rank matrix invertible

Therefore, a unified approach for the computation of {1,2,3} and {1,2,4}. Properties The invertible matrix theorem Let A be a square n-by-n matrix over a field K (e. What does the rank of a matrix tell us?. Note: A matrix is nonsingular ( | A | ≠ 0) then we are able to find its inverse form. melina goransson shroud; non orthogonal matrix support fbx maya; evc cpu compatibility matrix 12 gauge pistol grip attachment. So it's a square matrix. The columns of A are linearly independent. This generalizes the results of Vaserstein and Wheland on rings having stable rank one. Finding the rank of an non-invertible matrix. If A is invertible ker(A)=∅ then A is full rank. 30503459 0. Let Jn be the n X :0. The Mahalanobis distance is is effectively a weighted Euclidean distance where the weighting is determined by the sample variance-covariance matrix. · The columns of A span R n. The performances of three optimization methods were compared: (i) particle swarm optimization (PSO), (ii) genetic algorithm (GA), and (iii) the covariance matrix adaptation-evolution strategy (CMA-ES). He shows that for any matrix A, A T A has the same nullspace as A: (1) Clearly the nullspace of A is contained in the nullspace of A^T A. When the rank equals the smallest dimension it is called "full rank", a smaller rank is called "rank deficient". Admin almost 9 years suppose $A^TAx=0$ for some non zero $x$ then???. Definition of generalized inverse. (a) Express J. Let A ∈ Mm,n(C). Conditions (11)–(13) involve col(A), and by the rank-nullity theorem, this is immediately teth- ered to the null space nul(A). Math Advanced Math 3. Matrix Rank The rank is how many of the rows are "unique": not made of other rows. If a 2D . Common reasons for matrix invertibility are that one or. Now Ǝ ρ linearly independent rows in D, but the rows of D which are not. The orthogonal complement of the column space of A is {0}. Main article: Rank factorization Applicable to: m -by- n matrix A of rank r Decomposition: where C is an m -by- r full column rank matrix and F is an r -by- n full row rank matrix Comment: The rank factorization can be used to compute the Moore–Penrose pseudoinverse of A, [2] which one can apply to obtain all solutions of the linear system. a -1 1 such that A = 1-26 11 has the form A=PCP 1. Courses on Khan Academy are always 100% free. If A is not full rank let consider x ∈ k e r ( A) then A x = 0 and A ( 2 x) = 0 thus it is not injective and therefore not invertible. Less than n and x has full rank. It is invertible if and only if the columns of the design matrix are. Jun 06, 2022 · How do you know if a matrix is invertible full rank? By (13), A is invertible if and only if rank(A) = n. ٧ ذو القعدة ١٤٣٧ هـ. Proof of 'if' part Let A have an inverse B. Jun 06, 2022 · If A is full rank it is surjective (column space span Rn) and injective (x≠y Ax≠Ay) therefore it is invertible. Generate a random 3 by 3 matrix A with rank 3. Click to see full answer Is rank deficient matrix invertible?So it can't be invertible. (2) To show the reverse inclusion, suppose that A T A x = 0. This has important consequences; for instance, if A is an m × n matrix and m ≥ n, then rank (A) ≤ n, but if m < n, then rank (A) ≤ m. 0 is not an eigenvalue of matrix A. Proof of 'if' part Let A have an inverse B. 3 Attachments jpg jpg jpg. The conventional factorization models are based on the assumption that the data matrices are contaminated stochastically by some type of noise. full row rank if and only if is invertible. det (a) Compute the determinant of an array. 06649743 0. 2 Matrices Having All Elements Equal 102. Student Response A matrix to be invertible should be of full rank. And following outputs the eigenvalues (and their right eigenvectors) of that matrix. A square. Full rank matrices for A ∈ Rm×n we always have rank(A) ≤ min(m,n) we say A is full rank if rank(A) = min(m,n) • for square matrices, full rank means nonsingular • for skinny matrices (m ≥ n), full rank means columns are independent • for fat matrices (m ≤ n), full rank means rows are independent Linear algebra review 3–22. Prove that if A ∈ Rm×n, with m ≥ n, is full rank, then A⊤A is invertible via the following steps: Prove that Ax (vector) = 0 (vector) if and only if X = 0, prove that A T A is positive definite, prove that any positive definite matrix is always invertible by using Eigen decomposition to construct the inverse. (2) To show the reverse inclusion, suppose that A T A x = 0. The rank is at least 1, except for a zero matrix (a matrix made of all zeros) whose rank is 0. Numer-ical example is presented in Sect. 2) None of the entries of A are zero. Definition 2 (see [12]). If A is invertible k e r ( A) = ∅ then A is full rank. Because X ′ X is a square matrix (rows equal columns), it must have rows which are linearly dependent as well (i. Common reasons for matrix invertibility are that one or. There exist at least one minor of order 'r' that is non-zero. Note that the matrix B in the previous example is the 2 ⇥ 2 zero matrix. 27171651 # [7] 0. n > m ) and full rank. A is invertible. This is equivalent to the fact that its rows are independent as well. (2) To show the reverse inclusion, suppose that A T A x = 0. It does not indicate PINV is. 2 Descriptor Continuous-Time Linear. Thus, a non-singular matrix is also known as a full rank matrix. It relies upon three elementary row operations one can use on a matrix : Swap the positions of two of the rows. (b) Use this to show that fiJn is idempotent. When a Matrix and Its Inverse Are Nonnegative. It is known that $\text{rank}(A)=3$. I choose the initial conditions to be. One dimension is lost during linear transformation if matrix is not full rank by definition. strictly positive) real numbers. ٢٢ شعبان ١٤٣٨ هـ. If A is invertible ker(A)=∅ then A is full rank. Algebra formula in vertex form, find graph for linear and quadratic equation, canadian grade 8 math practice sheets. What is full rank matrix example? Example: for a 2×4 matrix the rank can't be larger than 2. If A is not full rank let consider x ∈ k e r ( A) then A x = 0 and A ( 2 x) = 0 thus it is not injective and therefore not invertible. What does the rank of a matrix tell us? 19,162 views Jul 30, 2013 143 Dislike Share Lorenzo Sadun 14. Matrix inverse, existence of inverse, matrix inverse by Gaussian elimination. The equation has only the trivial solution. In this case, we could multiply one of these equations by and the other by and all of the remaining equations by 0 and have the equations sum to zero. It is invertible if and only if the columns of the design matrix are linearly independent ---i. The row-rank of a matrix is equal to its rank, i. Nov 15, 2022 · and G^(z) is a m p transfer function matrix. full row rank if and only if is invertible. De nition: A matrix B is similar to a matrix A if there is an invertible matrix S such that B = S 1AS. Try the given examples, or type in your own problem and check your answer with the. It's only true if A is a square matrix. Therefore, I is not invertible, since I − 1 = ( X t) − 1 W − 1 X − 1. 16 Rank and Inverse Matrices 87. 2 Matrices Having All Elements Equal 102. Matrix Rank and the Inverse of a Full Rank Matrix 7 Definition. Modified 2 years, 5 months ago. The matrix is invertible; In full column rank matrices, or r = n < m. Low-rank matrix factorizations such as Principal Component Analysis (PCA), Singular Value Decomposition (SVD) and Non-negative Matrix Factorization (NMF) are a large class of methods for pursuing the low-rank approximation of a given data matrix. We also highlight the structure of nonsingular subspaces of dimension in M (R). – Ben Voigt Apr 28, 2014 at 17:11 Add a comment 2 Answers. The following notation will be used: R - the set of real numbers, Rn×m-the set of n×m real matrices and Rn = Rn×1, C - the field of complex numbers. If then has full row rank and will have dimensions , and rank , and be invertible. 5 Special Matrices 97. Rest of the statements are true. The rank of a matrix is defined as the maximum. The orthogonal. If A is invertible ker(A)=∅ then A is full rank. What is full rank matrix example? Example: for a 2×4 matrix the rank can't be larger than 2. by a rank (see Definition 2. It is known that $\text{rank}(A)=3$. . skyrim together reborn commands, cyber security in sanskrit, japan daughter porn, 42 tv for sale, ez whelp, susanville craigslist, tamilgun movie new 2022, deep throat bbc, fun graduation songs, hollow points, gm spindle identification chart, marble race name generator co8rr