Community Profile # Wan Ji

### Wuhan University

Last seen: Today 2021 以来アクティブ

Research Interest: computational mechanics and modeling the world

Programming Languages:
Python, C++, C, MATLAB, Fortran
Spoken Languages:
English, French, Mandarin

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#### Content Feed

Call a folder from desktop and use images inside it
Hey, friend, Using uigetfile is a nice choice, for example [file,path,indx] = uigetfile( ... {'*.jpg;*.png;*.tiff;*.tif;*.bmp...

Matlab default font monospace is not a wise choice
Did anyone encounter a problem when writing an m-script on matlab? The problem is that your naked eyes can't tell the number '1'...

### 1

How can I fix my function?
Hey， friend Just try the inline function ispythag = @(a,b,c)a.^2+b.^2 == c.^2; a = ispythag(1,2,3) b = ispythag(3,4,5) Then...

2ヶ月 前 | 0

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Matlab versions supported on Windows 11?
WINDOWS 11 itself should support running the softwares on win10. ELSE microsoft would not release it and clients would not use i...

3ヶ月 前 | 0

Using ODE45 for first order diff equation with three different variables
For example function dxdt = func(t,x,g) dxdt = zeros(3,1); dxdt(1) = (0.1*x(1))+(0.25*x(2))-(g*x(3)); dxdt(2) = (0.1*x(1))+(...

3ヶ月 前 | 2

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The Piggy Bank Problem
Given a cylindrical piggy bank with radius g and height y, return the bank's volume. [ g is first input argument.] Bonus though...

3ヶ月 前

how to write to solve this type of system of equations ?
Hey friend Just expand the left items of the two equations, extract u'' and v'', then an ode45 solver is there for you.

3ヶ月 前 | 0

multiple graphs in one script
Modified the code as %% 6 x = ([-2*pi:0.1:2*pi]); f = x-sin(x) g = 1-x.*cos(x) figure(1);clf; plot(x,f,x,g) title('f(x) &...

3ヶ月 前 | 0

How to check if an array is empty without using any built in functions
Use isempty x = []; isempty(x) Then the answer is ans = logical 1

3ヶ月 前 | 1

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I want to co-relate the local coordinate system with global co-ordinate system of a 8-noded element. How to do it in matlab?
You need to add the element information element_id = 5; % for example, the local element id is 5 selected_element = element(el...

3ヶ月 前 | 0

I don't know how to avoid eval
Hi friends from community, I am very confused on how to manage 'eval' function existing in my code, i need it to be removed fro...

3ヶ月 前 | 3 件の回答 | 0

### 3

Total Solution Differential Equation
If u(t) = 1, then your solution is right. If it is a function with respect to time, then your solution is wrong. Exact code: ...

3ヶ月 前 | 0

How to plot such figure in MATLAB?
use polarplot theta = 0:0.1:pi; r = 1+0.6*sin(10*theta); polarplot(theta,r); set(gca,'ThetaLim',[0 180]) set(gca,'Rdir','re...

3ヶ月 前 | 1

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How to plot a 3D vortex flow
If you donot have a mesh, then you need to reconstruct your mesh! X = X(:); Y = Y(:); Z = Z(:); U = U(:); V= V(:); W=W(:); min...

3ヶ月 前 | 0

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Saving the regression trained model
You should save the trained model after click the 'export' the model to workspace. (you can see you saved model in workspace) ...

3ヶ月 前 | 0

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Solving 3 simultaneous equations using solve.
Do not use 'pi' use pi instead %define attributes: gamma=21.05; phi=35.55; phi1=0.75*phi; d=0.6; syms L Rs Rb; zc=(0.3*ph...

3ヶ月 前 | 0

Calculate cosine without cos(x)
Solve cos(x). The use of the function cos() and sin() is not allowed.

3ヶ月 前

Approximate the cosine function
Without using MATLAB trigonometric functions, calculate the cosine of an argument |x| to a precision of |0.0001| *Hint:* You ...

3ヶ月 前

How to add consecutive numbers from a column in a .txt file?
Just use movsum a = [1 1 8 2 3 1]; b = movsum(a,2); % I should apologize for not adding 2 b = b(2:end) The answer b = ...

3ヶ月 前 | 1

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How do i write the function for the taylor polynomial of cos(x) using for loops and no anonymous function
If a large x is selected, then use function Pn = taylor_cos(a,n) x=mod(abs(a),2*pi); % if(x>=pi) x = 2*pi-x; end Pn=1;...

3ヶ月 前 | 0

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How to use sym and function handle(@) in same code
Hi, use matlabFunction, my friend syms theta Ai = cos(theta).*[1 1 2; 4 5 6; 9 1 3] Bi = tan(theta).*[6 9 1; ...

3ヶ月 前 | 0

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How to average first two dimension of 3D array/matrix?
Just use mean function to average first two dimension of 3D matrix a = rand(2,3,4); % I just use rand function so the result is...

3ヶ月 前 | 1

Save points or data in right order
I have answered this question before, now I have a better solution to this problem which can identify many connected regions cl...

3ヶ月 前 | 0

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How to make a={'1','2','3','4'} to b={'1234'}
The simple way is a={'1','2','3','4'}; b = {[a{:}]} Answer b = 1×1 cell array {'1234'}

3ヶ月 前 | 0

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how do you sum using loop?
x=1:100; f=@(x)x.*(1+x); S=sum(f(x));%this should be ok %or use loop f=@(x)x.*(1+x); S=0; for i=1:100 S=S+f(i); end...

3ヶ月 前 | 0

How to form a sphere with 1's in a 3D matrix
If there is no scale factor effect with different directions: m = 80; n = 100; p=90; [px,py,pz] = meshgrid(1:n, 1:m, 1:p); ra...

3ヶ月 前 | 1

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How to sum the values when they are bigger than 25, 50, 75, (conditional) and they are from the same group?
That's quite simple, you don't need to compare them clc;clear ID = ['1_A' ; '1_A'; '1_A'; '2_B'; '2_B'; '3_C'; '3_C';...

3ヶ月 前 | 0

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How to i change the SNR to Vector?
SNR = -20:10:30; a(numel(SNR)) = helperModClassTestChannel(); for i = 1:1:SNR a(i).SNR = SNR(i); end

3ヶ月 前 | 0

Why is it not taking the sqrt function, and how to fix it?
You should transform char format to double then do your work B = str2num(B); H = str2num(H); n = str2num(n); s = str2num(s);...

3ヶ月 前 | 0

plot the equation graph
Hi, It is not neccessary to solve this equation x = 0:0.00001:1; f = @(x,m,a)(m*pi+atan((x)/(1-x))+atan((a+x)/(1-x)))./sqrt(1...

3ヶ月 前 | 0