a excel-solution to do a mathematical fourier-tranform

[vinny31]

Hi all

I am looking for a excel-solution to do a mathematical fourier-tranformation of a sine wave plot
i have two colums of data, whic are time and velocity. this is the plot of velocity vs time.

can anyone tell me what to do or attach a *.xls example
or even a place to look which has a very simplified example
regards
v

 

[COEngineeer]

so you are trying to change your V(t) into a fourier fuction? Is this correct? I am very rusty on this subject.

 

[vinny31]

Hi

yes thats is correct
i beleive the new plot from the transform will be amplitude vs frequency.

 

[COEngineeer]

Well, why dont you give me the V(t) Ill see what I can do. I want to see if I can solve it first before I try to help you with the excel part (im not that great anyway with excel )

 

[COEngineeer]

Just give me one example of V(t) i meant. I know you are tyring to create a sheet that will convert it.

 

[vinny31]

ok no problem

here is the text version of it, as i cant see a way to upload it as a txt file



TIME velocity
1.00E-11 0.19311
1.00E-07 0
2.00E-07 -0.19311
3.00E-07 -1.2362
4.00E-07 -3.5372
5.00E-07 -6.4057
6.00E-07 -8.7034
7.00E-07 -9.2436
8.00E-07 -7.0239
9.00E-07 -2.2234
1.00E-06 3.8451
1.10E-06 9.2898
1.20E-06 12.089
1.30E-06 11.146
1.40E-06 6.907
1.50E-06 0.67129
1.60E-06 -5.6425
1.70E-06 -9.7452
1.80E-06 -10.397
1.90E-06 -7.5084
2.00E-06 -1.8796
2.10E-06 4.5196
2.20E-06 9.442
2.30E-06 11.393
2.40E-06 9.6913
2.50E-06 4.7556
2.60E-06 -1.597
2.70E-06 -7.2846
2.80E-06 -10.569
2.90E-06 -10.187
3.00E-06 -6.3144
3.10E-06 -0.37697
3.20E-06 5.7813
3.30E-06 10.104
3.40E-06 11.01
3.50E-06 8.3299
3.60E-06 2.9843
3.70E-06 -3.407
3.80E-06 -8.5774
3.90E-06 -10.787
4.00E-06 -9.462
4.10E-06 -4.9235
4.20E-06 1.3334
4.30E-06 7.0822
4.40E-06 10.504
4.50E-06 10.515
4.60E-06 6.9668
4.70E-06 1.1314
4.80E-06 -4.9705
4.90E-06 -9.4738
5.00E-06 -10.785
5.10E-06 -8.4128
5.20E-06 -3.2999
5.30E-06 2.9215
5.40E-06 8.2432
5.50E-06 10.766
5.60E-06 9.6954
5.70E-06 5.4935
5.80E-06 -0.58275
5.90E-06 -6.4597
6.00E-06 -10.081
6.10E-06 -10.391
6.20E-06 -7.2426
6.30E-06 -1.6057
6.40E-06 4.5206
6.50E-06 9.1127
6.60E-06 10.745
6.70E-06 8.7674
6.80E-06 3.8417
6.90E-06 -2.2645
7.00E-06 -7.6403
7.10E-06 -10.49
7.20E-06 -9.7579
7.30E-06 -5.8053
7.40E-06 4.69E-02
7.50E-06 5.945
7.60E-06 9.8421
7.70E-06 10.411
7.80E-06 7.5892
7.90E-06 2.2339
8.00E-06 -3.9042
8.10E-06 -8.6519
8.20E-06 -10.525
8.30E-06 -8.9279
8.40E-06 -4.2954
8.50E-06 1.7595
8.60E-06 7.1724
8.70E-06 10.248
8.80E-06 9.9146
8.90E-06 6.2234
9.00E-06 0.53159
9.10E-06 -5.3219
9.20E-06 -9.4444
9.30E-06 -10.356
9.40E-06 -7.8068
9.50E-06 -2.7097
9.60E-06 3.3288
9.70E-06 8.2702
9.80E-06 10.395
9.90E-06 9.0993
1.00E-05 4.8014

 

[COEngineeer]

Well, you have to convert that to a formula first before you can find the fourier transform. Like V(t)=A sin B Theta or something that will fit your curve. I thought you already had this fuction.

 

[Clyde38]

Have you tried the Fourier Analysis feature built in to Excel (Tools/Data Analysis/Fourier Analysis)?

 

[vinny31]

i looked for fourier in the excel help but nothing came up
so i thought it didnt have this function
and thats why i put up this post

 

[Clyde38]

Click on Tools | Data Analysis | Fourier Analysis, then click the Help in the Data Analysis window.

 

[prost]

This reference makes it sound pretty easy to Fourier transform a discrete set of data using existing capability in Excel

http://physics.oregonstate.edu/~tate/COURSES/

ph421/labs/FFT_notes.pdf

 

[joerd]

@Clyde38:
You'll need to install the Analysis Toolpak first or you won't have that menu option. (Tools/Add-ins, then check the box of Analysis Toolpak)

Cheers,
Joerd

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