FItting 3d with fourier

Hi everyone,

i'm working at a project in which i got a modelled velocity look like fitted by Fourier8, i have a lot of data and i need to fit u=f(y,z) of the file uploaded , can someone help me please?

Thanks in advance

BEST regards,

[Vincenzo Senatore]

here i link a text in which there is the kind of equation that i would like to obtain

Answer 1

[Alex Sha]

If taking the fitting function as:

the result will be:

Root of Mean Square Error (RMSE): 0.000481289122874164
Sum of Squared Residual: 8.10737269289438E-6
Correlation Coef. (R): 0.999538609101962
R-Square: 0.999077431085486

Parameter	Best Estimate
----------	-------------
a1	0.0031488389071083
b1	6601.65334793348
c1	-20970.8542584731
a2	-0.132911397446423
b2	3766.85965070268
c2	-1351.15719981604
a3	-0.00321037434029533
b3	-3711.04888391542
c3	10020.2474994826
a4	0.0506407098493067
b4	1263.92176950354
c4	-6128.76676017437
a5	0.00301960797708877
b5	-63934.3471383267
c5	-1699.94515972645

[Vincenzo Senatore]

Wow, great job

did you used curve fitting toolbox, or did you wrote a code?

If you have a code can pls show me?

Thanks so much

[Vincenzo Senatore]

sorry but this is my real workspace , with V=f(y,z), if you find other time pls can u help me with the real case because i didn't understand that u were solving it and i wasn't able to load the full text,

THanks so much,

Best regards.

Answer 2

[Alex Sha]

Hi, give your data as text format, not a picture just.

[Vincenzo Senatore]

% x y z u (m/s)

0.07500000000000001 9.98714572960106E-4 9.971543853941147E-4 0.03497429528800376

0.07487836833071332 9.936173372382116E-4 0.001008395852156714 0.03425689650784324

0.07500000000000001 0.0011403846071430092 0.0011403846071430092 0.008672067315736217

0.07500000000000001 0.0011417396108193822 8.967676127441027E-4 0.022889195836208607

0.07500000000000001 8.925655110220609E-4 0.0011357105402171853 0.022610070526922012

0.07482614950059001 9.636210303086351E-4 0.0011381209914482714 0.018400077633201586

0.07500000000000001 0.0010162667564994627 -0.001005663703866723 0.03124113446072542

0.07500000000000001 8.98404185718329E-4 -0.0011446537282721796 0.021959332761722208

0.07482607729734343 9.683904737601536E-4 -0.0011448346957637235 0.01790950047084396

0.07500000000000001 0.0011451096607011358 -0.0011451096607011356 0.007245189125480443

0.07482614950059001 0.00114561961353975 -9.689427400601984E-4 0.018583371152898324

0.07500000000000001 0.001145570437911778 -8.990465407303232E-4 0.0218301089252804

0.07500000000000001 9.82776685711893E-4 -8.092939760187956E-4 0.05422203391372652

0.07480937195502717 0.0011461334305731426 -7.694895640488774E-4 0.02493505773762861

0.07500000000000001 0.0011436952545670548 -6.447279202456797E-4 0.02940551646959344

0.07500000000000001 8.10410562638383E-4 -9.837972212583417E-4 0.05397984644074038

0.07500000000000001 -0.0010114764148818703 0.0010075276968973005 0.032996894970589434

0.07500000000000001 -0.0011453425637869008 8.988868652126945E-4 0.022016249359141125

0.07500000000000001 -0.0011493484185056049 0.001149348418505605 0.0069133463411109874

0.07480520180108952 -0.0011486800820674887 9.878081442107544E-4 0.015671660907793452

0.07500000000000001 -9.010759867108922E-4 0.001148466675441947 0.019578577720646143

0.07480114418801187 -9.974525778576292E-4 0.0011508083301088486 0.01509464219906776

0.07473976760120601 -7.595232964384615E-4 0.0011483357816608904 0.026547941944506204

0.07500000000000001 9.955582175745204E-4 8.184749407271094E-4 0.05310070839572382

0.07500000000000001 8.233249182415567E-4 9.944342261391666E-4 0.051625125934788484

0.07480926397216571 7.691950784599748E-4 -0.0011454291067929119 0.02486356666350796

0.07500000000000001 6.447840967298157E-4 -0.001143815372112309 0.029915507643631913

0.07480520180108952 0.0011404933638183555 9.817296673365083E-4 0.018014944537705895

0.07482539940702565 0.0010403311931317526 8.241354194746475E-4 0.044668730932862916

0.07500000000000001 0.0011390557934014213 6.432273484172861E-4 0.032270940699457254

0.07500000000000001 0.001007262160456279 5.710522871285882E-4 0.06629997352130443

0.07500000000000001 0.0011363821338043287 3.8677946212850925E-4 0.03942320727679514

0.07476052807431242 0.0011373281215402494 4.8706056754838886E-4 0.0351359036225163

0.07500000000000001 9.731082133912777E-4 -5.559645723277242E-4 0.07345991158625534

0.07500000000000001 0.0011394932907817644 -3.868137382808377E-4 0.03884778421035598

[sandesh amgai]

Hello Alex,

how did you code the double fourier function?