| Re: Relative distances between vector elements and search for matches in other vector. [message #80019 is a reply to message #80010] |
Wed, 25 April 2012 08:03   |
cgguido
Messages: 195
Registered: August 2005
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Senior Member |
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Also, I would also get nx=n_elements(xx) once and use it when I need it it.
Finally, your min for loop, I suspect one histogram could do it. but I am not sure what you're trying to do...
If you keep your loop then you could try this:
a = where( abs(ratio-ratio2[jjj]) LT 0.05 ,count)
and also avoid appending to stel_dep adn stel_wave by greating them outside the loop and filling as needed. Then clip one at the end.
PS: histogram wise... I'd start with something approximately like:
nr=n_elements(ratio)
nr2=n_elements(ratio2)
bigratio=rebin(ratio,[nr,nr2],/sample)
bigratio2=transpose(rebin(ratio2,[nr2,nr], /sample))
now you have two arrays that are the same size, so you can do:
diff=bigratio-bigratio2
;good is now filled with 1s and 0s
good=abs(diff) LT 0.05
;you can count them by using DIMENSION with total:
count=total(good,2)
...
On Wednesday, April 25, 2012 9:03:00 AM UTC-5, Trifon Trifonov wrote:
> Hallo all
> I am new in IDL but I am increasing my level everyday and I am so happy that I discover IDL!!!
> I stuck very badly in one algorithm that I am developing for my Pipeline.
> I am searching for a routine or method to:
>
> 1st. define the relative distances between vector elements ( e.g. distances between peaks in the spectrum(allready identified))
>
> 2nd. to identify the lines from another vector (bigger or smaller in array size)
> based on the criteria of the above (1st.)
>
> E.g.
>
> I have:
> RATIO_STLINES FLOAT = Array[21]
> 0.00000 -0.171038 -0.594733 -1.21922 -1.40923 -1.52994 -1.56168 -1.92495 -2.28294 -2.34803 -2.38444
> -3.15909 -3.46812 -3.61399 -3.97221 -4.09896 -4.27114 -4.43637 -5.69552 -6.05595 -6.23174
>
> RATIO_CAT FLOAT = Array[44]
> 0.00000 -0.209757 -0.249368 -0.930353 -1.05059 -1.21623 -1.21693 -1.74758 -1.75778 -1.77888 -1.78749
> -2.03075 -2.22571 -2.99081 -3.29190 -3.31060 -3.42393 -3.43413 -3.43844 -3.44364 -3.59758 -3.61648
> -3.76892 -3.80183 -3.92147 -4.26676 -4.53263 -5.02637 -5.31455 -5.35194 -5.52650 -5.59132 -5.75987
> -5.81128 -6.60440 -6.68362 -6.71653 -6.73373 -6.81295 -6.95529 -7.23017 -7.48834 -7.66608 -7.90535
>
> And the RATIO_CAT consist the lines from RATIO_STLINES (it is possible not all of them to be in the RATIO_CAT)
>
> So RATIO_STLINES is lets say shifted respect to RATIO_CAT and I want to identify lines based on their line ratios.
>
> I want to mention that I already made a working algorithm but I am 1000 % sure that the more experienced people here can help me to make it much more elegant and efficient. Later on I have a other problem on that I stuck but lets see can you help me on that and it is possible to solve it my self... if not I will post again :(
>
>
> Here is the code:
>
> ;Finding the peak of each line on the spectrum:
>
> peak = peaks(1-chip,0.9) ; finding the peaks from JJohnson IDL.
> ddd = xaxis[peak] ;wavelengths of the finded lines.
> lines = chip[peak] ;depts of the finded lines.
> ;xx - HITRAN lines
> ;z1- VALD catalog wavelengths
> ;z2 - VALD catalog line depths
>
> ;Finding the relative distance between the HITRAN lines (nm):
> ratio=fltarr(n_elements(xx))
>
> for j=0L, n_elements(xx)-1 do begin
> ratio[j] = xx[0] - xx[j]
> endfor
>
> ;Finding the relative distance between each line on the spectrum:
> ratio2=fltarr(n_elements(ddd))
>
> for jj=0L, n_elements(ddd)-1 do begin
> ratio2[jj] = ddd[0] - ddd[jj]
> endfor
>
> ;Finding the relative distance between the lines from the VALD catalog:
> ratio_vald=fltarr(n_elements(z1))
>
> for jjj=0L, n_elements(z1)-1 do begin
> ratio_vald[jjj] = z1[0] - z1[jjj]
> endfor
>
>
> ; Identify the telluric lines on the spectra. Only stellar lines will be left.
> telluric_depts = fltarr(n_elements(xx))
> telluric_waves = fltarr(n_elements(xx))
> stel_dep = []
> stel_wave = []
> stel_ra = []
> for jjj = 0L, n_elements(ratio2)-1 do begin
> a = where((ratio GT (ratio2[jjj] - 0.05)) and (ratio LT (ratio2[jjj] + 0.05)),count)
>
> if count gt 0d0 then begin
> telluric_depts[a] = lines[jjj]
> telluric_waves[a] = ddd[jjj]
> endif
>
> if count le 0d0 then begin
> stel_dep =[stel_dep, lines[jjj]]
> stel_wave =[stel_wave, ddd[jjj]]
> ;stel_ra = [stel_ra,ratio2[jjj]]
> endif
>
> endfor
>
> ;Finding the relative distance between the lines that left from the science spectrum:
>
> ratio_stlines = fltarr(n_elements(stel_wave))
> for k = 0L, n_elements(stel_wave) - 1 do begin
> ratio_stlines[k] = stel_wave[0] - stel_wave[k]
> endfor
>
>
> And I will stop here because I have more problems below...
>
> Thank you very much in advance!
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