Alan Stevens
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644 total contributions since 2020
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Answered
Non-Linear Coupled First-Order ODEs (with multiple derivative terms in each equation).
These ode's can be rearranged as follows: As long as you know initial values for a, b and c, then given that you know everyth...
Non-Linear Coupled First-Order ODEs (with multiple derivative terms in each equation).
These ode's can be rearranged as follows: As long as you know initial values for a, b and c, then given that you know everyth...
etwa 14 Stunden ago | 0
| accepted
Answered
How can i make the integral curves?
Like so? [x,y] = meshgrid(1:0.5:6,-3:0.5:2); u = ones(size(x)); v = (x.*y+y.^3)/2*x.^2; r = sqrt(u.^2 + v.^2); plot([0,0],[...
How can i make the integral curves?
Like so? [x,y] = meshgrid(1:0.5:6,-3:0.5:2); u = ones(size(x)); v = (x.*y+y.^3)/2*x.^2; r = sqrt(u.^2 + v.^2); plot([0,0],[...
ein Tag ago | 0
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Answered
Convert one matrix to two matrices with the order of the initial matrix
Try r1 = r; r1(:,2:2:end) = 0; r2 = r; r2(:,1:2:end) = 0;
Convert one matrix to two matrices with the order of the initial matrix
Try r1 = r; r1(:,2:2:end) = 0; r2 = r; r2(:,1:2:end) = 0;
ein Tag ago | 1
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Answered
How to clump/consolidate values together using the mean function
Here's one way cw = 4; %cell width a = 1:8; b = (1:8)'; c = a.*b; mat=ones(8,8); %temporary matrix avfn = @(m) mean(m,'A...
How to clump/consolidate values together using the mean function
Here's one way cw = 4; %cell width a = 1:8; b = (1:8)'; c = a.*b; mat=ones(8,8); %temporary matrix avfn = @(m) mean(m,'A...
ein Tag ago | 0
Answered
solve non linear equations
Add these lines at the end to get the values of S and J Soln = vpasolve([eqn1, eqn2],[S, J],[1 1]); disp(Soln.S) disp(Soln.J)...
solve non linear equations
Add these lines at the end to get the values of S and J Soln = vpasolve([eqn1, eqn2],[S, J],[1 1]); disp(Soln.S) disp(Soln.J)...
ein Tag ago | 0
Answered
How to find an unknown in an integral equation
Here's one way: nA0 = 1; % Initial guess nA = fzero(@fn, nA0); disp(nA) function Z = fn(nA) alphaA = 0.52; T ...
How to find an unknown in an integral equation
Here's one way: nA0 = 1; % Initial guess nA = fzero(@fn, nA0); disp(nA) function Z = fn(nA) alphaA = 0.52; T ...
3 Tage ago | 0
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Answered
Error: Function definition not supported in this context. Create functions in code file.
You need to turn Z=sin(2*pi*fc*p)./(pi*p); %Define truncated Sinc function% into Z=sin(2*pi*fc*p)./(pi*p); %Define trunca...
Error: Function definition not supported in this context. Create functions in code file.
You need to turn Z=sin(2*pi*fc*p)./(pi*p); %Define truncated Sinc function% into Z=sin(2*pi*fc*p)./(pi*p); %Define trunca...
3 Tage ago | 1
Answered
Using a another function within ODE45
More like this (but note the comments near the end): %Default Values m_c = 2; % Container Mass s1 = 16; ...
Using a another function within ODE45
More like this (but note the comments near the end): %Default Values m_c = 2; % Container Mass s1 = 16; ...
3 Tage ago | 1
| accepted
Answered
Conditionals within ODE45
You could try the following simplistic approach %Default Values m_c = 2; % Container Mass s1 = 16; % Sp...
Conditionals within ODE45
You could try the following simplistic approach %Default Values m_c = 2; % Container Mass s1 = 16; % Sp...
3 Tage ago | 1
| accepted
Answered
Need Help..............Error using stem (line 43) X must be same length as Y.
Either you want stem(t,xaa); or you want to use t1 in the definitions of xa11, xa22 etc.
Need Help..............Error using stem (line 43) X must be same length as Y.
Either you want stem(t,xaa); or you want to use t1 in the definitions of xa11, xa22 etc.
3 Tage ago | 1
Answered
What am I doing wrong here I keep getting a plot with either to many things on it or not enough all I want is a plot with two y axis and an x axis
Like this g = 9.81; theta = 46.97; theta2= 55; v1= 13.5; v2= 16.05; x= (0:0.1:2.3); x2= (0:0.1:5.14); y= x*tan(the...
What am I doing wrong here I keep getting a plot with either to many things on it or not enough all I want is a plot with two y axis and an x axis
Like this g = 9.81; theta = 46.97; theta2= 55; v1= 13.5; v2= 16.05; x= (0:0.1:2.3); x2= (0:0.1:5.14); y= x*tan(the...
3 Tage ago | 0
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Answered
Two linear equation with absolute value equation
Do you mean something like this X0 = [-50 -5]; [X, Fval] = fminsearch(@(X) fn(X),X0); x2 = X(1); x1 = 50-x2; x4 = X(2); x3 =...
Two linear equation with absolute value equation
Do you mean something like this X0 = [-50 -5]; [X, Fval] = fminsearch(@(X) fn(X),X0); x2 = X(1); x1 = 50-x2; x4 = X(2); x3 =...
4 Tage ago | 1
Answered
10%+10%
Because the % symbol indicates that the rest of the line is a comment. So the only non comment parameter Matlab sees is the fir...
10%+10%
Because the % symbol indicates that the rest of the line is a comment. So the only non comment parameter Matlab sees is the fir...
4 Tage ago | 1
| accepted
Answered
Function handling problem in loop
Try doc str2num to convert from text to numeric. Also, you might find it easier to define: k = [5.16 5.12 4.89 4.79 4.99 5.4...
Function handling problem in loop
Try doc str2num to convert from text to numeric. Also, you might find it easier to define: k = [5.16 5.12 4.89 4.79 4.99 5.4...
4 Tage ago | 0
| accepted
Answered
I can't randomly distribute the dots
Try using Yikikz=rand(size(Elevation)).*Elevation;
I can't randomly distribute the dots
Try using Yikikz=rand(size(Elevation)).*Elevation;
4 Tage ago | 1
Answered
How to fix error in fsolve
Is it just a case of changing F(1) = X(1) - exp(13.5-(2700/(x(3)-55))); to F(1) = x(1) - exp(13.5-(2700/(x(3)-55)));
How to fix error in fsolve
Is it just a case of changing F(1) = X(1) - exp(13.5-(2700/(x(3)-55))); to F(1) = x(1) - exp(13.5-(2700/(x(3)-55)));
4 Tage ago | 1
Answered
Error in using Integration, How to fix it ?
Since x has t in the denominator. t=0 will cause problems, so start at t = 0.02 instead, perhaps! This would require a change i...
Error in using Integration, How to fix it ?
Since x has t in the denominator. t=0 will cause problems, so start at t = 0.02 instead, perhaps! This would require a change i...
5 Tage ago | 0
| accepted
Answered
Ode and monod solver
Your equation has the following analytic solution (assuming Xa is a constant): You can plug in the known values for S0 (ie. t...
Ode and monod solver
Your equation has the following analytic solution (assuming Xa is a constant): You can plug in the known values for S0 (ie. t...
5 Tage ago | 1
| accepted
Answered
How to plot a large data set with markers to differentiate two overlapping lines?
How about plotting every n points. For example plot(t(1:1000:end),n_d(1:1000:end),'o') hold on plot(t(500:1000:end),n_r(500:...
How to plot a large data set with markers to differentiate two overlapping lines?
How about plotting every n points. For example plot(t(1:1000:end),n_d(1:1000:end),'o') hold on plot(t(500:1000:end),n_r(500:...
6 Tage ago | 0
| accepted
Answered
there is also a mistake here i can't recognize it , please help
You need N = [-V3*cos(th3(ii))-40*W2(ii).^2*cos(th2(ii))+C(ii)*W3(ii).^2*cos(th3(ii))+V3*W3(ii)*sin(th3(ii)); V3*sin(t...
there is also a mistake here i can't recognize it , please help
You need N = [-V3*cos(th3(ii))-40*W2(ii).^2*cos(th2(ii))+C(ii)*W3(ii).^2*cos(th3(ii))+V3*W3(ii)*sin(th3(ii)); V3*sin(t...
6 Tage ago | 0
Answered
How to vectorize this function?
You need a ./ (i.e. dot /) x3=@(phi) (R-((3-2.*sin(phi))./(1-0.5.*sin(phi)).*R)/4).*cos(phi) ...
How to vectorize this function?
You need a ./ (i.e. dot /) x3=@(phi) (R-((3-2.*sin(phi))./(1-0.5.*sin(phi)).*R)/4).*cos(phi) ...
6 Tage ago | 0
Answered
Plotting graph with Alpha and spectral radius
It works if you set i = 0.1:0.1:10. With i = 0; the inverse of S is full of Inf's.
Plotting graph with Alpha and spectral radius
It works if you set i = 0.1:0.1:10. With i = 0; the inverse of S is full of Inf's.
6 Tage ago | 0
| accepted
Answered
Conditional with time in ode45
Include upsilon within the odefcn mu = 6.25e10^-3; eta = 6.25e10^-3; beta = 0.03813350836; gamma = 0.01165323939; delta = 1...
Conditional with time in ode45
Include upsilon within the odefcn mu = 6.25e10^-3; eta = 6.25e10^-3; beta = 0.03813350836; gamma = 0.01165323939; delta = 1...
7 Tage ago | 0
| accepted
Answered
what's wrong with this code. why it show error can anyone tell?
You probably want something like this (don't enclose it with the statement 'function matlab' - that won't work). Remember to in...
what's wrong with this code. why it show error can anyone tell?
You probably want something like this (don't enclose it with the statement 'function matlab' - that won't work). Remember to in...
7 Tage ago | 0
Answered
Plot with 2 parameters
Do you mean something like this: theta = -90:90; ri = 0.5; ro = 1.5; x = [ri*cosd(theta) ro*cosd(-theta) 0]; y = [ri*sind(th...
Plot with 2 parameters
Do you mean something like this: theta = -90:90; ri = 0.5; ro = 1.5; x = [ri*cosd(theta) ro*cosd(-theta) 0]; y = [ri*sind(th...
8 Tage ago | 1
Answered
Please, how can I solve runKut4 in line 6?
Try t = 0.0; tStop = 6.0; y = [1.5 0]; h = 0.1; [T,Y] = ode45(@dEqs,[0 tStop],y); plot(T,Y(:,1),'ko-') xlabel('time (s)')...
Please, how can I solve runKut4 in line 6?
Try t = 0.0; tStop = 6.0; y = [1.5 0]; h = 0.1; [T,Y] = ode45(@dEqs,[0 tStop],y); plot(T,Y(:,1),'ko-') xlabel('time (s)')...
8 Tage ago | 0
| accepted
Answered
ode45 function matrix dimensions problem
You need to loop through the Y_H values. See below global mu_H Ks X_BH teta Ss_in mu_Hmax=0.15; %days^-1 T=22.6; %centigrad...
ode45 function matrix dimensions problem
You need to loop through the Y_H values. See below global mu_H Ks X_BH teta Ss_in mu_Hmax=0.15; %days^-1 T=22.6; %centigrad...
8 Tage ago | 0
Answered
I am getting this error "Assignment has more non-singleton rhs dimensions than non-singleton subscripts". Please help. Mw, Cw and Kw are 243X243 matrices.
It gets past your indicated Error line for me, but fails because you haven't defined Mw, Cw or Kw.
I am getting this error "Assignment has more non-singleton rhs dimensions than non-singleton subscripts". Please help. Mw, Cw and Kw are 243X243 matrices.
It gets past your indicated Error line for me, but fails because you haven't defined Mw, Cw or Kw.
9 Tage ago | 0
Answered
Error: Unable to perform assignment because the left and right sides have a different number of elements.
There are a lot of missing indices and definitions. In the following the indices are repaired; however, you will need to define ...
Error: Unable to perform assignment because the left and right sides have a different number of elements.
There are a lot of missing indices and definitions. In the following the indices are repaired; however, you will need to define ...
9 Tage ago | 0
| accepted
Answered
Grading system in excel sheet based on marks
Shouldn't you have for i = 1:1:N if R(i)>=80 table.StudentGrade{i} = 'A'; elseif R(i)>=70 table.StudentGrade{i} = 'B...
Grading system in excel sheet based on marks
Shouldn't you have for i = 1:1:N if R(i)>=80 table.StudentGrade{i} = 'A'; elseif R(i)>=70 table.StudentGrade{i} = 'B...
9 Tage ago | 0
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