Matrix multiplication (MMULT) and a matrix inverse (MINVERSE) are used to solve a set of 5 linear equations. Matrix operations in Excel are input as a range with a result calculated by using CTRL-SHIFT-ENTER.
Thank you so much. You can also nest the MINVERSE formula within the MMULT to get it done in one go. =MMULT(MINVERSE(array), array2) Specifically for the cells in this sheet: =MMULT(MINVERSE(B2:F6), H2:H6)
For your last step you can drastically speed up the process using =sumproduct on a transposition of either the result or the input to double check. The formula is cleaner too.
The matrix may be singular, meaning that there is no solution. Try using a 10x10 matrix that has random numbers to verify that you have the appropriate solution method procedure.
Yes, that either means that the matrix inverse isn't possible (singular matrix) or else the dimensions aren't correct. Make sure you have the inverse of the matrix (19x19) that you solve first. Then you multiply the matrix inverse by the right hand side that should be 19x1. The result should also be 19x1 so make sure that many cells are selected before you hit CTRL+SHIFT+ENTER. Here is an online condition number calculator although I haven't tried it personally. calculator.vhex.net/calculator/linear-algebra/condition-number-of-a-matrix
Yes, here is the Matlab version of this material: apmonitor.com/che263/index.php/Main/MatlabSolveEquations The course has Excel, Matlab, and Python material.
That seems like a tricky one because you don't necessarily have the keystroke combinations to select CTRL-SHIFT-ENTER. Maybe try a program other than Excel or else get a BlueTooth or USB keyboard that will connect to your smartphone.
