How to apply moving harmonic average on an array?

Question

Nisar Ahmed 2022-7-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1752760-how-to-apply-moving-harmonic-average-on-an-array

编辑： dpb 2022-7-4

KD.mat

Hi,

I have attached the data Kd_i = (115*1), I want to keep first and last values as it is in the data (or also shown in the figure below) and in the row want compute the harmonic average of first and second values (red square), in the 3rd row I want to compute the harmonic average of second and thrid values (green square) asn so on...

I mean first and last values remain same (just to have final array/vector of equal length), and then from second row it moves the by computing the harmonic mean of first and second row, until second last row. Can someone help me to write it code?

Thanks

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Abhishek Tiwari 2022-7-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1752760-how-to-apply-moving-harmonic-average-on-an-array#answer_999245

在 MATLAB Online 中打开

Hi,

A 'For' loop and harmmean() may do the same thing, as shown.

n = numel(Kd_i);
harmonicMean = Kd_i;
for idx = 2:n-1
    harmonicMean(idx) = harmmean(Kd_i(idx-1 : idx, 1));
end

3 个评论
显示 1更早的评论隐藏 1更早的评论

Abhishek Tiwari 2022-7-4

Yeah, harmonicMean has first and last values from Kd_i, and the remaining are the harmonic means of two rows (prev. and current).

Nisar Ahmed 2022-7-4

thanks

请先登录，再进行评论。

Answer 2

Star Strider 2022-7-3

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1752760-how-to-apply-moving-harmonic-average-on-an-array#answer_999240

在 MATLAB Online 中打开

If you want to calculate it as described in the harmmean More About section, perhaps something like this would work —

movhm = @(x) 2./movsum(1./x,2);
v = 1:5
v = 1×5
     1     2     3     4     5
movhm(v)
ans = 1×5
    2.0000    1.3333    2.4000    3.4286    4.4444

would work.

.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 3

dpb 2022-7-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1752760-how-to-apply-moving-harmonic-average-on-an-array#answer_999235

编辑：dpb 2022-7-4

在 MATLAB Online 中打开

Simplest is probably just brute-force --

HM=[Kd_1(1) arrayfun(@(i)harmmean(Kd_1(i:i+1)),1:numel(Kd_1)-1) Kd_1(end)].';

2 个评论
显示无隐藏无

Nisar Ahmed 2022-7-4

@dpb What is K here; harmmean(K(i:i+1)), is it the same Kd_i? and if I change as K = Kd_i, following error appears

Error using vertcat

Dimensions of arrays being concatenated are not consistent.

Error in Const_Q_Full_Mackbeth (line 90)

Kd_HM = [Kd_i(1); arrayfun(@(i)harmmean(Kd_i(i:i+1)),1:numel(Kd_i)-1);Kd_i(end)];

dpb 2022-7-4

Yeah, I made a local array of K=Kd_1(1:15) so wasn't too much to look at in command window...then didn't fix -- and arrayfun returns row vector didn't transpose...

请先登录，再进行评论。