hello can some one help. I am to find peaks of accelrometer axis, for that am using the previously suggested code in this form,

2 次查看（过去 30 天）
Mirbahar Naadiya
Mirbahar Naadiya 2017-11-26
回答： Star Strider 2017-11-26
if true
% code
I am trying the same code with my data and data file is attached.and getting errror in interp1. can somone help me to solve. Error using griddedInterpolant
The grid vectors must contain unique points.
Error in interp1 (line 158) F = griddedInterpolant(Xext,V,method);
endif true
% code
[d,s,r] = xlsread('New Microsoft Excel Worksheet.xlsx')
d(d==0)=NaN
d = d(:,1:4)
t = d(:,1)
t=datetime(time,'ConvertFrom', 'posixtime')
t=second(t)
[dnanr,~] = find(isnan(d(:,2:4)))
d(dnanr,:) = [] % Delete NaN Rows
di = interp1(d(:,1), d(:,2:4), t) % Interpolate Missing Values
ftd = fft(di)/size(di,1) % Use ‘fft’ To Design Filter
%ftd(1,:) = 0
%ftda = abs(ftd)
Ts = mean(diff(t))
Fs = 1/Ts
Fn = Fs/2
Fv = linspace(0, 1, size(d,1)/2+1)*Fn;
Ix = 1:length(Fv)
Wp = [0.005 0.015]/Fn % Design Filter
Ws = [0.001 0.018]/Fn
Rp = 1
Rs = 10
[n,Wn] = buttord(Wp, Ws, Rp, Rs);
[b,a] = butter(n,Wn);
[sos,g] = tf2sos(b,a);
df = filtfilt(sos, g, di); % Filter Data
[pka1,pki1] = findpeaks(df(:,1), 'MinPeakDistance',100)
[pka2,pki2] = findpeaks(df(:,2), 'MinPeakDistance',100)
[pka3,pki3] = findpeaks(df(:,3), 'MinPeakDistance',100);
figure(1) % Plot Filtered Data & Peaks
subplot(3,1,1)
plot(t, df(:,1))
hold on
plot(t(pki1),df(pki1,1),'r^')
hold off
grid
subplot(3,1,2)
plot(t, df(:,2))
hold on
plot(t(pki2),df(pki2,2),'r^')
hold off
grid
subplot(3,1,3)
plot(t, df(:,3))
hold on
plot(t(pki3),df(pki3,3),'r^')
hold off
grid
figure(2) % Plot FFT
plot(Fv, ftda(Ix,:))
grid
set(gca, 'XLim',[0.0 0.05]);
end
  3 个评论
显示 1更早的评论
Mirbahar Naadiya
Mirbahar Naadiya 2017-11-26
if true
% code
Error using griddedInterpolant
The grid vectors must contain unique points.
Error in interp1 (line 158)
F = griddedInterpolant(Xext,V,method);
end
Image Analyst
Image Analyst 2017-11-26
Why does the error not make sense to you? It's saying that you have duplicated points in your vectors.
This is the one way to solve your problem : http://blogs.mathworks.com/videos/2012/07/03/debugging-in-matlab/ since you've chosen not to upload your workbook. Even if you do upload your workbook, it's still the best path to solving this.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

Star Strider
Star Strider 2017-11-26
You can create unique independent variable values from duplicated values by multiplying the duplicated-values vector by an increasing vector of very small values.
This works:
fudgefactor = cumsum(ones(size(d(:,1)))) * 1E-12;
di = interp1(d(:,1).*fudgefactor, d(:,2:4), t); % Interpolate Missing Values
I leave you to determine if it produces the result you want. (I only ran your code to the first interp1 call, since that threw the error.)

类别

在 Help Center 和 File Exchange 中查找有关 Parametric Spectral Estimation 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by