- #1
SweetBabyLou
- 6
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Hello all,
I've got a somewhat mixed concept question from a Chemical Engineering computational methods class. I'm completely lost with this question, as I do not fully understand what it entails. The question (and data) is this:
Data Set Given
X Y
0.00 -2.17
0.05 -1.34
0.10 -0.43
0.15 0.32
0.20 0.84
0.25 1.12
0.30 1.74
0.35 1.83
0.40 2.13
0.45 2.54
0.50 2.44
0.55 2.57
0.60 2.43
0.65 2.37
0.70 2.08
0.75 1.68
0.80 1.28
0.85 0.83
0.90 0.32
0.95 -0.17
1.00 -1.19
f1(x;c1,c2,c3) = c1 + c2x + c3x2
f2(x;c1,c2,c3) = c1 + c2xcos(∏x) + c3sin(∏x)
Make two plots: data points plus f1(x) and data points plus f2(x)
I do know the excel end of the function - of how I am supposed to carry out the rest of this problem (taking the inverse of the matrix formulated, finding the boundaries, and finally, finding the coefficients) and I do know that I need a few columns with each row corresponding to the given data. These columns would form the matrix needed to carry out the rest of the problem. What I am hung up on is how I go about building the initial matrix that undergoes these operations. I would think that it would have something to do with ordinary differential equations (ODEs) or basis functions.
At first, I tried deriving the "correlations" until I reached a constant, but quickly realized that I would need C2 to find C3 and vice versa. Unfortunately, I don't have much knowledge in the way of differential equations (save finding general solutions/ solutions to simple ODEs).
Some other knowledge I do know is that these correlations resemble power series, as well.If anyone can spare some extra brain power to explain the concept/give advice as to how I should go about completing this problem, I would greatly, GREATLY appreciate it.
Thanks
I've got a somewhat mixed concept question from a Chemical Engineering computational methods class. I'm completely lost with this question, as I do not fully understand what it entails. The question (and data) is this:
Homework Statement
Data Set Given
X Y
0.00 -2.17
0.05 -1.34
0.10 -0.43
0.15 0.32
0.20 0.84
0.25 1.12
0.30 1.74
0.35 1.83
0.40 2.13
0.45 2.54
0.50 2.44
0.55 2.57
0.60 2.43
0.65 2.37
0.70 2.08
0.75 1.68
0.80 1.28
0.85 0.83
0.90 0.32
0.95 -0.17
1.00 -1.19
Homework Equations
Use the rectangular-matrix formulation and Excel matric functionality to obtain a least-squares fit to these data with each of the following two correlations:f1(x;c1,c2,c3) = c1 + c2x + c3x2
f2(x;c1,c2,c3) = c1 + c2xcos(∏x) + c3sin(∏x)
Make two plots: data points plus f1(x) and data points plus f2(x)
The Attempt at a Solution
I do know the excel end of the function - of how I am supposed to carry out the rest of this problem (taking the inverse of the matrix formulated, finding the boundaries, and finally, finding the coefficients) and I do know that I need a few columns with each row corresponding to the given data. These columns would form the matrix needed to carry out the rest of the problem. What I am hung up on is how I go about building the initial matrix that undergoes these operations. I would think that it would have something to do with ordinary differential equations (ODEs) or basis functions.
At first, I tried deriving the "correlations" until I reached a constant, but quickly realized that I would need C2 to find C3 and vice versa. Unfortunately, I don't have much knowledge in the way of differential equations (save finding general solutions/ solutions to simple ODEs).
Some other knowledge I do know is that these correlations resemble power series, as well.If anyone can spare some extra brain power to explain the concept/give advice as to how I should go about completing this problem, I would greatly, GREATLY appreciate it.
Thanks
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