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Chunru


Last seen: Today Active since 2013

Matlab user since 1990

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Answered
How to trasform from cell to matrix and transpose from horizontal to vertical at the same time?
Data.my_cell{1} = randn(1, 11); Data.my_cell{2} = randn(1, 11); Data.my_cell{3} = randn(1, 11); Data.my_cell my_matrix = cel...

4 hours ago | 1

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Answered
How do I zoom in on a certain section of a magnitude bode plot
num = [1]; den = [1 0.04946 3.00316 0.0989847 3.00322 0.0494631 1.00006]; g=tf(num, den) bode(g) grid on ax = findobj(gcf, ...

5 hours ago | 0

Answered
Obtaining Sine Wave From Square Wave
% generate a square wave with no fixed period f = 0.125; fs=1; s = 0.3+sin(2*pi*f*(0:40)); % a sine wave with offset x =2* (...

6 hours ago | 0

Answered
why do I get this error while using qammod? "Expected input number 1, X, to be an array with all of the values < 4."
A few bugs in program. The major one is generating input signa which should bel: tx_bits=randi([0 M-1], [N_data_symbol,1]); N...

6 hours ago | 1

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Answered
Using trapz function to provide answers using loop
% The way to use trapz x= 1:20; % x y = randn(20, 1); % y ytrapz = trapz(x, y) % integr...

9 hours ago | 0

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Answered
Storing sparse matrices in cell or struct without converting them to full
The sparse array in cell is still sparse array as shown below, Can you show the problem you have encountered? a = sparse(eye(1...

9 hours ago | 0

Answered
How to import exponent number from Excel column to MATLAB
x = readtable("2powx.xlsx") y = cellfun(@(a) sscanf(a, "%d^%d")', x.LSB, "UniformOutput", false) y = cell2mat(y) y = y(:, 1)....

1 day ago | 0

Answered
How to fit a gaussian distribution curve on a bar diagram?
p = [1/36,2/36,3/36,4/36,5/36,6/36,5/36,4/36,3/36,2/36,1/36]; xsum =[2,3,4,5,6,7,8,9,10,11,12] ; bar(xsum, p) mu = sum(p.*xsu...

1 day ago | 0

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Answered
Why do I get error when using a simple global variable?
Not sure what the code is trying to do. However, the error is due to the wrong usage of ( ) rather than global variables. glob...

1 day ago | 1

Answered
How can I plot direction of principal components in PCA
x = randn(4, 2); plot(x(:,1), x(:,2), 'ro', 'DisplayName', 'data'); axis equal; hold on p = pca(x); xc = mean(x); quiver(x...

1 day ago | 0

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Answered
Smoothing data with sgolay filter
framelen = 11; order = 3; % adjust these values smootheddata = sgolayfilt(z, order, framelen);

1 day ago | 0

Answered
Unrecognized function or variable 'sum'.
classdef question2 methods function q2a = l1qa(~,table) % clear sum; s...

1 day ago | 0

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Answered
I have a 2x2 matrix with values [0.5694 -0.8220; -0.8220 -0.5694] How do I plot this matrix?
x = [0.5694 -0.8220; -0.8220 -0.5694] heatmap(x); figure plot(x(:, 1), x(:,2)) % take 1st column as x and 2nd column as y (...

1 day ago | 0

Answered
Get the displacement component which is perpendicular to the triangle (finite element)
% In order to know the normal of triangle, you need the coordinated of % triangle postri = randn(3, 3) % x y z v = dif...

1 day ago | 0

Answered
Separating a timestamp into individual components
times = [ 20082009 21082009 22082009 23082009]; d = floor(times/1e6); m = mod(floor(times/...

1 day ago | 0

Answered
Suppress Window using System Command
cd("C:\Program Files\Bentley\Offshore\MAXSURF CONNECT Edition V23") cmd = "MaxsurfModeler64.exe display off" system(cmd)

1 day ago | 0

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Answered
plot graphs with a range
R = 2.303 * 8.314; T = 273 + 20; F = 96500; Eqv = @(z, Xout, Xin) ((R * T) / (z * F)) * log(Xout/Xin); fprintf("<Question 1:...

1 day ago | 0

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Answered
Scatter plot with mean for multiple groups
x = readtable("https://www.mathworks.com/matlabcentral/answers/uploaded_files/1136975/MATLAB_exampledata.xlsx"); x.Group = cate...

1 day ago | 0

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Answered
Find the first value that is greater than or equal to and its corresponding value
data =[ 0.01 3 0.02 4 0.03 6 0.04 9 0.05 12 0.06 14 0.07 15 0.08 18]; idx = find(dat...

1 day ago | 0

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Answered
How can I insert many columns into a matrix at different locations efficiently?
%Create some "data" A = rand(100); %some random data col = randsample(100,15); A(:, col)=zeros(100,15); %some random columns ...

1 day ago | 0

Answered
I am not sure why my function is undefined for input arguments double.
x = rand([-20 20]); % generate random number in range [-20 20] % call the function % output function_name input_argume...

2 days ago | 0

Answered
How to get the intensity value of the flower
im = imread("https://www.mathworks.com/matlabcentral/answers/uploaded_files/1136290/image.jpeg"); whos im = rgb2gray(im); ...

2 days ago | 0

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Answered
How to convert a sym variable to an ordinary variable?
t= linspace(-1,3); syms x_t(t); x_2(t) = piecewise(t<-1,(2),-1<t<=-.5,(t.*4+6),-.5<t<2, (-2.4*t+3),t==2,(2),t>=2, (2)); y ...

2 days ago | 0

Answered
how can I plot a trajectory of moving point ?
npts=1; v=28.8/3.6; radius=1000; center=[0 0]; MOVE(npts, v, radius, center) function MOVE(npts, v, radius, center) d...

2 days ago | 0

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Answered
can anyone help me ? i keep getting this error
num_roots=5; num_functions=6; %initial guess for roots (from Wolfram MathWorld) zeros_guess=[2.4,3.8,5.1,6,7.5,8.7;... 5.5...

3 days ago | 0

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Answered
Use a grid/image get positional inputs and measure time in-between clicks.
You can make your function based on ginput or getpts. Edit one of these matlab functions and add the output argument of t and r...

3 days ago | 0

Answered
Having trouble calling a user defined function.
TableOne = array2table([1988*ones(10,1) randn(10, 2)]) TableTwo = array2table([1988*ones(10,1) randn(10, 2)]) %This complete...

3 days ago | 0

Answered
Volume formed by a moving triangle
% initial triangle p1 = [0, 0, 0]; p2 = [3, 0, 0]; p3 = [0 4 0]; % the velocity vector should be specified (instead of final t...

6 days ago | 0

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Answered
How could I sums up 1/n for n=1 to 10000?
It can be run as shown below. What problem have you encountered? n = 10000; % whatever you want sum_harm = 0; for i = 1:n ...

6 days ago | 0

Answered
i need series representation for the equation of erfc(x) and maching with it in plot
x = 0.5; format long erfc(x) for n=1:20 y(n) = erfc_by_series(x, n); end y' function y= erfc_by_series(x, n) ...

6 days ago | 0

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