Does Matlab have a command to make data smoother like the smooth command in IDL?

Question

Nopparat 2012 年 9 月 9 日

0
リンク

この質問への直接リンク

https://jp.mathworks.com/matlabcentral/answers/47693-does-matlab-have-a-command-to-make-data-smoother-like-the-smooth-command-in-idl

For IDL command,

"The SMOOTH function returns a copy of Array smoothed with a boxcar average of the specified width. The result has the same type and dimensions as Array" ( http://idlastro.gsfc.nasa.gov/idl_html_help/SMOOTH.html). The example of the result is following;

The original data

       7.79008      4.15141      7.48622
       1.69548      6.31630      6.84862
       7.00782      2.78159      7.85362
       5.91996     0.659594      5.77286
       8.38353      3.33698      9.03057
       7.64424     0.474168      5.77164
       3.62966      8.94523      4.11056
       9.33464      1.19968      4.66864
       5.79112      3.83709      1.43494

The result data ( IDL> print, smooth(x,3,/edge) )

       5.31274      5.66250      6.01227
       5.21623      5.58725      5.95827
       5.11973      5.51200      5.90428
       5.42783      5.47206      5.51628
       5.41093      5.25468      5.09842
       5.39403      5.03729      4.68056
       5.54293      5.28162      5.02030
       5.60563      4.92210      4.23857
       5.66832      4.56258      3.45685

Thank you in advance.

0 件のコメント
-2 件の古いコメントを表示-2 件の古いコメントを非表示

サインインしてコメントする。

サインインしてこの質問に回答する。

Answer 1

Image Analyst 2012 年 9 月 9 日

2
リンク

この回答への直接リンク

https://jp.mathworks.com/matlabcentral/answers/47693-does-matlab-have-a-command-to-make-data-smoother-like-the-smooth-command-in-idl#answer_58295

MATLAB Online で開く

Ordinarily I'd do this:

smoothed_m = conv2(m, ones(3)/9, 'same')

but modified to fix any edge effects:

numerator = conv2(m, ones(3), 'same')
denom = conv2(ones(size(m)), ones(3), 'same')
smoothed_m2 = numerator ./ denom

but it doesn't give you the same output values. However I'm not sure how you got those values. For example, let's take the middle value, which is totally not affected by edge effects. You say it's 5.25468 however in MATLAB:

m9 = [...
   5.91996     0.659594      5.77286
       8.38353      3.33698      9.03057
       7.64424     0.474168      5.77164]
averageValue = mean2(m9)
averageValue =
    5.2215