How can I make this work Please? In AccelerationWeek10 (line 10) Index exceeds matrix dimensions. Error in AccelerationWeek10 (line 31) s = s(1:npts/2+1); % truncate (removes complex conjugates)

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Stephen Bell 2018-5-13

0
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https://ww2.mathworks.cn/matlabcentral/answers/400575-how-can-i-make-this-work-please-in-accelerationweek10-line-10-index-exceeds-matrix-dimensions

评论： Walter Roberson 2018-5-15

close all
npts = 2^15;
sfreq = 22150;
dt = 1/sfreq;
t = (0:npts-1)'*dt;
m = 500 % mass
k = 1000000;
c= 1000;
naturalFr = sqrt(k/m)
 sim('week7')% Simulink
figure(1)
plot(Accel)
xlabel('Time [s]')
ylabel('Signal [units]')
s = fft(Accel.Data);%3
figure(2)
subplot(211)
plot(real(s))
grid on
xlabel('Index')
ylabel('Real')
subplot(212)
plot(imag(s))
grid on
xlabel('Index')
ylabel('Real')
% % folding and scaling
Line 31  s = s(1:npts/2+1); % truncate (removes complex conjugates)
s = s/npts; % scale 
s(2:end-1) = 2* s(2:end-1); % fold 6 
df = sfreq/npts;
freq = (0:npts/2)'*df;
mag = abs(s);% 7
% mag1 = sqrt(imag(s).^2+real(s).^2);% 
mag1 = atan(imag(s)/real(s));
figure(3)
plot(freq,mag)
hold on
plot(freq,mag1)
grid on
xlabel('Frequency [Hz]')
ylabel('Magnitude [units]')

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Image Analyst 2018-5-14

在 MATLAB Online 中打开

Line 10 is

sim('week7')% Simulink

NOT

s = s(1:npts/2+1); % truncate (removes complex conjugates)

Please explain the discrepancy. Please post the actual code you are using because I'm not sure, because of the line number discrepancy, what code you're actually running.

Stephen Bell 2018-5-14