![]() ![]() EIGENVALUES MATLAB DONT MATCH MATHCAD MANUALThe Scipy manual was not very helpful, it just lists the input and output for the lapack function. Whenever you delete one parenthesis, Mathcad deletes the matched parenthesis. EIGENVALUES MATLAB DONT MATCH MATHCAD INSTALLYou would need to install Python, Scipy, and xlwings to run it. If you do not have Web access you can contact Mathsoft International for. Let me know if you want a copy of the required VBA and Python code to run the function. example d eigs (A,k) returns the k largest magnitude eigenvalues. This is most useful when computing all of the eigenvalues with eig is computationally expensive, such as with large sparse matrices. GAUSS does not have window capabilities, but info is. The second input n gives the size of matrix A used in Afun. Description example d eigs (A) returns a vector of the six largest magnitude eigenvalues of matrix A. The packages MATLAB, O-MATRIX, MathPlus, and Mathcad make use of these navigation tools and other. ![]() d eigs (Afun,n, ) specifies a function handle Afun instead of a matrix. You can optionally specify k, sigma, opts, or name-value pairs as additional input arguments. In the attached file, on sheet1, I have copied all the Scipy function results to column 2, and I have converted the function call to text in cell A1. d eigs (A,B, ) solves the generalized eigenvalue problem AV BVD. Also the following results are approximately equal to the Matlab results, but diverge after the 3rd significant figure. Return a vector of indices that relate the eigenvalues to their linearly independent eigenvectors. I wrote a VBA routine to copy the upper triangle to the lower triangle, to ensure that they were symmetrical, and after doing that only the first result was negative. Compute the exact eigenvalues and eigenvectors of a 4-by-4 symbolic matrix. With the matrices taken from your files, and using the Scipy front-end to dsygv, the first two results are negative as you found. I called that from Excel with xlwings, using the two Excel files you posted in another forum (the ones you linked to here seem to be text files, and had some problems with the numbers being corrupted when I imported them). The values of that satisfy the equation are the eigenvalues. 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. I had a look at this using the Python Scipy library, which includes a front end to the Lapack functions. V,D,W eig(A) also returns full matrix W whose columns are the corresponding left eigenvectors, so that WA DW. ![]()
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