Community Profile # Chunru

Last seen: Today Active since 2013

Matlab user since 1990

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How can I generate sinusoidal signal with a time-varying frequency?
fs = 100e3; % 100kHz sampling frequency ts = 1/fs; Time = ts:ts:84986*ts; % 0.84986 sec load('Freq.mat'); % 84.986 freque...

ungefär 17 timmar ago | 0

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Remove row if its value is not different enough from the value in the row above it.
% Generate data latency = [1000 1010 1020 1800]'; dur = zeros(size(latency)); type = ones(size(latency)) * 256; T = table(...

ungefär 19 timmar ago | 0

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sum of series of matrix
A = randn(5, 5, 99); B = zeros(5, 5, 33); for i=1:33 B(:, :, i) = sum(A(:, :, (i-1)*3+(1:3)), 3); end whos B

ungefär 19 timmar ago | 2

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What is the equation used for taylor window function 'taylorwin'
The formulation of Taylor windown is a bit more complicated and not directly documented in "doc taylorwin". One reference is: ...

ungefär 21 timmar ago | 0

Assign values of array to indices of another array
A = [1; 2; 3; 4]; B = [11; 22; 33; 44]; B(A) A = [0; 2; 3; 4]; C = zeros(size(A)); C(A>0) = B(A(A>0))

ungefär 21 timmar ago | 0

matlab coder report Size mismatch (size [0 x 0] ~= size [1 x 2])
... coord_list = zeros(n, m1); % m1 is the length of yy below I_list = zeros(n, m2); % m2 is the lenght of zz ... fo...

en dag ago | 0

How to convert latitude and longitude of location to cartesian coordinates (x, y)?
First, you need a reference point. Second you have to assume that the posints are close enough to the reference points so that ...

en dag ago | 0

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how to use sprintf for xticklabel?
x = 0.1005:0.1:1.1005; y = randn(size(x)); plot(x, y) grid % for x tick format xtickformat('%.2f') % Conversion of array t...

en dag ago | 0

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extract numbers from text file
T = readtable("data.txt"); T=T(:, 2:end) x = table2array(T)

3 dagar ago | 1

How to convert negative numbers in parentheses (bank-formatted text) to numbers with minus sign?
xbank = [" (1,234)" "2,345,678" "(1,234.56)"] x = arrayfun(@bank2double, xbank) function x = bank2double(s) s...

10 dagar ago | 0

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Combine mat files into one, then combine all variables into one
filename = ["abc001.mat" "def002.mat"]; % list of the files in order variable1all = []; variable2all = []; for i=1:leng...

12 dagar ago | 0

there is nan in a column, delete the whole row
idx = isnan(c.lagpe); % find the index of nan c(idx, :) =[]; % remove the rows from table

12 dagar ago | 0

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How can I automate a process for n times?
J = [14 0 0 0 0; 15 0 0 0 0; 16 16 16 0 0; 22 22 0 0 0; 24 24 0 0 0; 25 25 25 25 25] Lr = size(J,1); for i = 1:Lr row = J...

13 dagar ago | 1

Program code for convolution
u = [1 2 3 1]; v = [2 3]; conv(u, v) % filter(u, 1, v)

14 dagar ago | 0

plotting a surface on a cylinder top face
theta =0:0.01*pi:2*pi; r=0.8; x=r*cos(theta); y=r*sin(theta); z=zeros(size(x)); % simple patch for base p_base =patch(x,...

14 dagar ago | 0

How to remove cell data from specific column using dates as a reference?

15 dagar ago | 0

combine two cell into one string

15 dagar ago | 0

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Echo+noise signal
% generate a waveform f0 =100; fs=1000; pw = 0.1; pri = 1; npulses = 10; s = cos(2*pi*f0*(0:1/fs:pw))'; % it can be ...

15 dagar ago | 1

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Spectogram Of I and Q data
x = xi + 1i*xq; spectrogram(x)

16 dagar ago | 0

Transfer Quarterly dates to Monthly
% Your data dtstr = ["31/3/1992" "30/6/1992" "30/9/1992" "31/12/1992"]; x = [1.2 1.3 1.4 1.5]...

16 dagar ago | 0

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What is the training accuracy of this model?
If Labels is character array instead of string array, then numel(Labels) will give the number of characters instead of the numbe...

16 dagar ago | 0

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Get coordinates points inside a 3-D circle in MATLAB
normal=[-3.5556 -0.2222 1.0000]; center=[138 146 219]; radius=3; plotCircle3D(center,normal,radius); hold on point = p...

16 dagar ago | 0

How can I label multiple routes on a geoscatter plot?
fig = figure; %pos = fig.Position; %files = dir('cast*.gpx'); for i = 1:5 %length(files) %filename = files(i).name; ...

18 dagar ago | 0

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operation on single elements in MATLAB
x=-2:1:2; %coordinates x y=x.^2; %coordinates y z=[x;y] d = diff(z, 1, 2) % diff along 2nd dim d = vecnorm(d...

19 dagar ago | 1

specifying frequencies in pwelch not working
No problem for on-line matlab. data = randn(20000,1); %assume this is 1 row of my EEG data of interest analysisWinSize = 1000...

19 dagar ago | 0

Create duration array template
ti = duration('00:00:0.00','Format','hh:mm:ss.SSS'); tf = duration('02:00:0.00','Format','hh:mm:ss.SSS'); interval = millise...

19 dagar ago | 0

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Multiply values in array by *-1
a = randn(1, 106); a(14:20) a(16:18)=-a(16:18); a(14:20)

20 dagar ago | 0

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How to find sum of previous 5 numbers in a column..
x = [56 45 56 678 678 568 2 3 4 5]; y = filter(ones(5,1), 1, x) y1 = y(5:end)

20 dagar ago | 0

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Graph function problem Incorrect values
What's wrong? x=[0:50]; y=-x.^3+3*x.^2+2*x-27; plot(x,y)

20 dagar ago | 0

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