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Chunru


Last seen: Today Active since 2013

Matlab user since 1990

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Answered
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...

4 dagen ago | 0

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Answered
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...

7 dagen ago | 0

Answered
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

7 dagen ago | 0

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Answered
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...

8 dagen ago | 1

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

8 dagen ago | 0

Answered
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,...

9 dagen ago | 0

Answered
How to remove cell data from specific column using dates as a reference?
T = readtable("https://www.mathworks.com/matlabcentral/answers/uploaded_files/1085695/flowrate_dates.xlsx", "Sheet", 3) idx = T...

9 dagen ago | 0

Answered
combine two cell into one string
t = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1085370/SummaryResult%20-%20Copy.xlsx'); t = t(1:...

10 dagen ago | 0

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Answered
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 ...

10 dagen ago | 1

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

10 dagen ago | 0

Answered
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]...

10 dagen ago | 0

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Answered
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...

11 dagen ago | 0

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Answered
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...

11 dagen ago | 0

Answered
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; ...

13 dagen ago | 0

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Answered
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...

14 dagen ago | 1

Answered
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...

14 dagen ago | 0

Answered
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...

14 dagen ago | 0

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

14 dagen ago | 0

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Answered
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)

14 dagen ago | 0

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

14 dagen ago | 0

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Answered
How to reduce running time of diagonal matrix multiplication with full matrix in Matlab?
n = 2000; d=500; B = randn(d, n); dv = randn(n, 1); D = diag(dv); % Normal tic A = B*D*B'; toc % Speed up 1 tic C = ...

14 dagen ago | 0

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Answered
How to make a number NaN when its both neighbours are NaN?
A = [NaN 2.35 NaN 2.358 1.68 1.98 2.88 NaN 2.68 NaN 2.70 NaN 2.20 NaN 3.03; NaN NaN 2.77 NaN 2.67 1.87 2.56 1.88 2.39 NaN...

15 dagen ago | 0

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Answered
adding an if condition so the negative value would be set to zero
for i=1:length(t) DOD(i)=cumsum((T(i)*30)/(3600*14.6)); end DOD = max(DOD, 0)

15 dagen ago | 0

Answered
Circular bar graph in matlab
% Some data T.Country = string(('A':'Z')'); T.Population = randi([1000 10000], size(T.Country)); T = struct2table(T); n = he...

15 dagen ago | 1

Answered
Plot with break in curve
xy=[0.0000 -963.0477 0.0043 -961.9818 0.0085 -960.8602 0.0128 -959.6834 0.0171 -958.4515 0.0214 -957.16...

15 dagen ago | 0

Answered
removing the pixels with different size and unregular shape
A simple approach is to find the regions you want to deleted (assign 0). Four your question, rectangle regions are sufficient: ...

16 dagen ago | 1

Answered
How to plot like this graph?
% [1 2][3 4] % [6 7] h(1) = subplot(2, 4, [1 2]); % 4x2 grid, 1st subplot plot(randn(10, 1)); h(2) = subplot(2, 4, ...

16 dagen ago | 0

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Answered
Error using mesh Z must be a matrix, not a scalar or vector. Error in untitled6 (line 5) mesh(W,Y,Z)
w = 200:50:450; y=120:30:240; [W,Y] = meshgrid(w,y); Z= 64.0189+1.4629*W-2.626*Y-0.0012*W.^2+0.0098*W.*Y+0.0082*Y.^2; whos ...

16 dagen ago | 0

Answered
How to read .XY file?
file='random_x.txt'; fid = fopen(file, 'rt'); i=1; s1 = ''; while ~feof(fid) s{i} = [s1 fgetl(fid)]; %...

16 dagen ago | 0

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Answered
regexp function - get index of string with two conditions
str = {'strawberry/banana#(';'apple#,melon*cherry';'apple_banana_cherry'}; s = regexp(str, '^apple.*(cherry)$', 'match'); id...

17 dagen ago | 0

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