comp.lang.idl-pvwave archive: archive » Using 1D FFT to decompose the provided hurricane data in terms of wavenumbers.

Home » Public Forums » archive » Using 1D FFT to decompose the provided hurricane data in terms of wavenumbers.

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Using 1D FFT to decompose the provided hurricane data in terms of wavenumbers. [message #90487]

Wed, 04 March 2015 15:10

twiel002
Messages: 1
Registered: March 2015

Junior Member

I have 240x240 array of hurricane wind speed.

1) I need to covert to polar coordinates and plot the speed on a contour map with a radius of [-108,108], however what I have doesn't appear to be correct.

My Code:

Pro Projet2COORD

;;;---Reading in the data---;;;

rows = 240
cols = 240
spd = FltArr(240,240)
OpenR, lun, 'speed.csv', /Get_Lun
ReadF, lun, spd
Free_Lun, lun
print, spd

rows = 240
cols = 240
X = FltArr(240,240)
OpenR, lun, 'Xdir.csv', /Get_Lun
ReadF, lun, X
Free_Lun, lun
print, X

rows = 240
cols = 240
Y = FltArr(240,240)
OpenR, lun, 'Ydir.csv', /Get_Lun
ReadF, lun, Y
Free_Lun, lun
print, Y

;;;---Interpolate the coordinates---;;;

R=sqrt(X^2+Y^2)
Theta=atan(Y/X)*2*!PI
spd1=Polar_Surface(spd, R, Theta)

unsmooth = CONTOUR(spd1, TITLE='Hurricane Wind Speed', $
LAYOUT=[2,1,1], RGB_TABLE=13, /FILL, N_LEVELS=12)

; Draw the outline of the 12 levels
outline1 = CONTOUR(spd1, N_LEVELS=12, /OVERPLOT)

2) I need to then decompose the speed into wavenumbers using a 1D FFT, however I have no idea how to plot these wavenumbers on a similar plot to the polar plot from above.
I need wavenumbers 0-3, the sum of those wavenumbers, and wavenumbers 0-9.
Any assistance is appreciated.

Report message to a moderator

[Message index]

		Using 1D FFT to decompose the provided hurricane data in terms of wavenumbers. By: twiel002 on Wed, 04 March 2015 15:10
		Re: Using 1D FFT to decompose the provided hurricane data in terms of wavenumbers. By: Burch on Thu, 05 March 2015 07:32
		Re: Using 1D FFT to decompose the provided hurricane data in terms of wavenumbers. By: Burch on Thu, 05 March 2015 07:41

Previous Topic:	FG Bug -- Legend/Cleanup
Next Topic:	FG Save method -- Gifs

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 13:58:55 PDT 2025

Total time taken to generate the page: 0.00497 seconds