i followed the instructions wherein i have to solve this equation x+y=8 x+2y=12 which must be the result the x=4 y=4 i tried it until 6:50 but the result came only x=4 is right but the y doesn’t result 4 its blank. what should i do ☹️
+alinuman15, here are videos on solving ODEs and DAEs: apmonitor.com/che263/index.php/Main/MatlabDynamicSim (see links at the bottom for solving with Python or Excel). I don't have anything on SVMs or image processing although Python and MATLAB have good modules / toolboxes for both. For example, take a look at OpenCV for image processing.
The last row in matrix A [1, 1, 1, 1] constant is [807] and the results from the HP48 variables satisfy the equation exactly. I take that as proof. Maybe I’ll try excel solver.
That's a good point. The matrix is rank deficient so there are probably multiple solutions that satisfy the equations. There is no unique solution to that problem because A isn't invertible. You need to check all of the equations, not just the last one to make sure that the solution is valid.
Thank you so much for that, but there is mistake in solving 3X3 matrix in entering the values of matrix b where it is suppose to be (6,1,1) instead of (6,1,-1). The right answer will be (-5,6,1) instead (3,-2,1). regards
+alinuman15, see 10:25 where I enter in the values. The right hand side is correct because I just separated the variables from the constant by bringing them to separate sides. It should be (6,1,1) if we also multiply the other side by -1. I think the solution is correct in the video. Let me know if I miss something else.
You Are right. Both solutions correct. for verification we have to get:- AX=b. For your AX= [6,1,-1] when I use your X=3,-2,1 with your A: 1 -2 -1 2 2 -1 1 1 -2 and, when I use my X=[-5,6,1] with my A as 1 2 -1 2 2 -1 -1 -1 2 The multiplication will return b=[6,1,1]. Accept my regards
Equation #1 doesn't seem to be satisfied with [-5,6,1]. The original equation is x-2*y-z = 6. With [-5,6,1], that gives -18 = 6. There should be only one solution to this problem as long as none of the rows (equations) are linearly dependent. Linearly dependent equations are the same line but have all the terms scaled by a factor. We don't have linearly dependent or parallel lines in this problem so there is only one unique solution. I checked [3,-2,1] and all of the original equations are satisfied (Left Hand Side = Right Hand Side). Thanks for the great discussion - I really appreciate when there are comments such as yours because it shows that you are understanding the methods.
I don't know why don't we just use the linear modeling Add-Ins of MS Excel. It is far more flexible and easier than this Video. What if the problem is some kind of 10,000 inequality equations and 3,000 unknowns. Is this approach still practical?
I have the following system of linear equations I am trying to solve in Excel. My HP48GX solves the problem with the correct answer. However; the exact same entry in Excel gives a very different incorrect answer. A [[7.75, 7.75, 31.5, 31.5][-10, -34, -10, -58][2.25, 26.25, -21.5, 26.5][1, 1, 1, 1]] X [F1, F2, F3, F4] = B [15736.5, -26227.5, 0, 807]. The Result in Excel is [5.91E+18, -5.9E+18, -3E+18, 2.95E+18] and the answer from the HP48GX is [143.43, 117.07, 299.6, 246.89] The HP answer checks correctly and is entered exactly the same way as in Excel.Any idea why? Tnx in advance for your help.
The A matrix has a zero eigenvalue and a large condition number. It appears that Excel is correct - I entered them on Excel and in MATLAB. You may want to check the numbers that you entered on the HP48GX again.
lets say I have equation l*b=a how to make excel calculate one of the values among l, b and a when I enter two other values. in other words, normally we enter value of l and b in two cells and enter formula of area in third cell. I want to be able to enter value of a and l to give me b. and enter a and b to give me l. and enter l and b to give me a.
One way to do this is to write a VBA macro that will detect which cell is blank and then calculate it. Unfortunately, there is no easy way to switch which one is specified versus calculated without re-typing the equations.
Thanks a lot, this really helped me resolved a two-month old statistical burden in as early as 6:30 (1st example). God bless you.
awesome video
Great job, very nice explanation,congratulatiions and many thanks.
Great Job, I never knew excel is capable of this. Thank you so much !
You no longer need to hit Ctrl+Shift to enter an array formula. They just work normally.
Thanks for that update!
Thanks sir! It is much helpful tool for a working Engineer like me.
sumankumar jha, I'm glad you enjoyed it. The course is at apmonitor.com/che263 for more content.
Thanks a lot sir
Thank you so much, that part at 6:30 helped me a lot
i followed the instructions wherein i have to solve this equation
x+y=8
x+2y=12
which must be the result the
x=4
y=4
i tried it until 6:50 but the result came only x=4 is right but the y doesn’t result 4 its blank. what should i do ☹️
You may be redefining your definition of x. Here are additional tutorials: apmonitor.com/che263
wow, so good, thanks a lot
Do you have any videos about solving differential equations, Support Vector Machine, image processing with python?
Thank you in advance!
+alinuman15, here are videos on solving ODEs and DAEs: apmonitor.com/che263/index.php/Main/MatlabDynamicSim (see links at the bottom for solving with Python or Excel). I don't have anything on SVMs or image processing although Python and MATLAB have good modules / toolboxes for both. For example, take a look at OpenCV for image processing.
The last row in matrix A [1, 1, 1, 1] constant is [807] and the results from the HP48 variables satisfy the equation exactly. I take that as proof. Maybe I’ll try excel solver.
That's a good point. The matrix is rank deficient so there are probably multiple solutions that satisfy the equations. There is no unique solution to that problem because A isn't invertible. You need to check all of the equations, not just the last one to make sure that the solution is valid.
Thank you so much for that, but there is mistake in solving 3X3 matrix in entering the values of matrix b where it is suppose to be (6,1,1) instead of (6,1,-1). The right answer will be (-5,6,1) instead (3,-2,1).
regards
+alinuman15, see 10:25 where I enter in the values. The right hand side is correct because I just separated the variables from the constant by bringing them to separate sides. It should be (6,1,1) if we also multiply the other side by -1. I think the solution is correct in the video. Let me know if I miss something else.
You Are right. Both solutions correct. for verification we have to get:- AX=b. For your AX= [6,1,-1] when I use your X=3,-2,1 with your A:
1 -2 -1
2 2 -1
1 1 -2
and, when I use my X=[-5,6,1] with my A as
1 2 -1
2 2 -1
-1 -1 2
The multiplication will return b=[6,1,1].
Accept my regards
But, I still have about why we don't have unique answer for that problem ?
Equation #1 doesn't seem to be satisfied with [-5,6,1]. The original equation is x-2*y-z = 6. With [-5,6,1], that gives -18 = 6. There should be only one solution to this problem as long as none of the rows (equations) are linearly dependent. Linearly dependent equations are the same line but have all the terms scaled by a factor. We don't have linearly dependent or parallel lines in this problem so there is only one unique solution. I checked [3,-2,1] and all of the original equations are satisfied (Left Hand Side = Right Hand Side). Thanks for the great discussion - I really appreciate when there are comments such as yours because it shows that you are understanding the methods.
Thank you!!!
Who is watching this video during online computer exam to get the answers
I don't know why don't we just use the linear modeling Add-Ins of MS Excel. It is far more flexible and easier than this Video. What if the problem is some kind of 10,000 inequality equations and 3,000 unknowns. Is this approach still practical?
That larger system is not very practical with Excel. Try Python or MATLAB: apmonitor.com/pdc/index.php/Main/LinearProgramming
I have the following system of linear equations I am trying to solve in Excel. My HP48GX solves the problem with the correct answer. However; the exact same entry in Excel gives a very different incorrect answer. A [[7.75, 7.75, 31.5, 31.5][-10, -34, -10, -58][2.25, 26.25, -21.5, 26.5][1, 1, 1, 1]] X [F1, F2, F3, F4] = B [15736.5, -26227.5, 0, 807]. The Result in Excel is [5.91E+18, -5.9E+18, -3E+18, 2.95E+18] and the answer from the HP48GX is [143.43, 117.07, 299.6, 246.89] The HP answer checks correctly and is entered exactly the same way as in Excel.Any idea why? Tnx in advance for your help.
The A matrix has a zero eigenvalue and a large condition number. It appears that Excel is correct - I entered them on Excel and in MATLAB. You may want to check the numbers that you entered on the HP48GX again.
lets say I have equation l*b=a
how to make excel calculate one of the values among l, b and a when I enter two other values.
in other words,
normally we enter value of l and b in two cells and enter formula of area in third cell.
I want to be able to enter value of a and l to give me b.
and enter a and b to give me l.
and enter l and b to give me a.
One way to do this is to write a VBA macro that will detect which cell is blank and then calculate it. Unfortunately, there is no easy way to switch which one is specified versus calculated without re-typing the equations.