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naivegaussianelimination doesn't work  2nd post, same problem
Having done some further investigation into this tutorials problem from the previous post (lecture 15) I further simplified the code to eliminate all the code in the first for loop except the line that creates the factor. I ran the code and expected to see all the modified b(i)'s as a result using the pause in the loop. But there was still a problem with the wrong number of parameters. Going back to some of my previous monkeying around with some of your examples, I recalled there being a function called factor(). Renaming factor to faktor the problem about the wrong number of parameters went away! So this example has at least two problems! This being the second one, and the first is the wrong code inside the 3rd loop evaluating A(i,j).
1011M 5060SSept. 17, 2019, 9:45 a.m. maxcy

tutorial 15 not working
http://spokentutorial.org/watch/Scilab/Linear%2Bequations%2BGaussian%2BMethods/English/\r\nIn this tutorial the first loop in the code makes an UT array. Or, at least it's supposed to.\r\nLooking at this code using the debugger with breaks set at 32 and 34 I get the following results for the loop indexes: k=1, j=2, i=2 for the first iteration of the code.\r\nLine 32 shows the factor, line 34 shows the code to zero out the following columns below the index element.\r\nAt line 32: factor = A(2,1)/A(1,1) is evaluated at the given index values which is OK. A(1,1) to normalize the row and A(2,1) to get rid of the first col in the following row. That's OK.\r\nAt line 34 we get A(i,j)=A(i,j)factor*A(k,j) which resolves to\r\nA(2,2)=A(2,2)factor*A(1,2) using the i, j, k values. Not good!\r\nThis code should resolve to \r\nA(2,1)=A(2,1)  factor * A(1,1)\r\n to set A(2,1) to zero, the rest of the loop changes the other elements in this row by the same factor. So this loop is screwed up. If I change the code so A(2,1) is used where it should, the element is now zero, but the code shows an index error when I run it. So I'll have to monkey around with the code to make the UT array, but there is definitely a problem with this example! \r\nAnd the last loop back substitutes to get the solution: I hope the last loop works as I have not tried it yet!\r\nI modified the original code to make debugging simpler: I hard wired in the A and b arrays, and deleted the back substitution section, so I can focus only on the UT matrix code.
1112M 5060SSept. 17, 2019, 10:50 p.m. maxcy

1Introduction to Scilab and its benefits

2Self learning of Scilab through Spoken Tutorials

3The amazing resource of Scilab Textbook Companion

4Scilab Lab migration, Toolboxes and Forums

5Installing

6Getting Started

7Vector Operations

8Matrix Operations

9Conditional Branching

10Iteration

11Scripts and Functions

12Plotting 2D graphs

13Xcos Introduction

14File handling

15User Defined Input and Output

16Integration

17Solving Non linear Equations

Linear equations Gaussian Methods

19Linear equations Iterative Methods

20Interpolation

21ODE Euler methods

22ODE Applications

23Optimization Using Karmarkar Function

24Digital Signal Processing

25Control systems

26Discrete systems

27Calling User Defined Functions in XCOS

28Simulating a PID controller using XCOS
Questions posted on ST Forums:
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Outline:
* Explain Gauss Elimination method algorithm * Explain code for Gauss Elimination method and solve an example using this code * Explain Gauss Jordan method algorithm * Explain code for Gauss Jordan method and solve an example using this code
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