Answered
solving odes that matrices should be update in every step.
I made some changes in your code. Pay attention to refreshing parameters: function sdot = ODEFUN(t,x) g1 = interp1...

6 years ago | 0

Answered
calculation the angle betwen X-axis created due coordinate system rotation - after projection the coordinate system on the plane
Here is an idea of how to project axis onto plane: Unit vector (normal) of a plane: Distance to plane: Axis projected onto pl...

6 years ago | 0

Answered
how to generate a circel which filed with regular points?
Here is an idea: Increase radius: Number of points on radius:

6 years ago | 0

| accepted

Answered
Error solving Boundary value Problem using bv4pc function
Try r = 1e-3 I think you forgot about dydr(1) and dydr(3) function dydr = odefun(r,y,phi,chi) dydr=zeros(4,1); % dydr(1) =...

6 years ago | 0

| accepted

Answered
Convert patch isosurface to surf
Use griddata and meshgrid

6 years ago | 0

| accepted

Answered
ODE15s running slowly for ODE with long expressions
Moreover, whenever I paused the computation to see what was happening, it always paused in files like 'sym', 'char', 'size', 'di...

6 years ago | 0

| accepted

Answered
How to change the position of arrow in quiver from head/tail to middle of the line?
Use scale scale = 0.5; quiver(...,scale)

6 years ago | 0

Answered
Graph of time against angle for multiple values of theta
You'll have only 2 curves: a=1; g=9.81*100; theta = linspace(1,7,20)*pi/16; hold on for h0 = [30 40] tau = ((h0.^(5/2))...

6 years ago | 0

| accepted

Answered
how to solve this bvp4c?
I re-wrote the main equations (compare yours and mine) and tried b = 1 Check the attachment

6 years ago | 1

| accepted

Answered
Calculate the distance between objects area using matlab.
Use this I1 = edge(I); [m,n] = size(I1); ldist = zeros(1,m); for i = 1:m ind = find(I1(i,:)); % find ind...

6 years ago | 1

| accepted

Answered
how will i get a mesh in 2d region
I tried to simplify the task (plain rectangle instead of ellipse(cylinder)) Here is what i got clc,clear data = load('simpl...

6 years ago | 0

Answered
Find path between two points with X and Y coordinates
I reached a succes p = xlsread('coordinates'); x = p(:,1); y = p(:,2); plot(x,y,'.r') hold on for i = 1:length(x)-1 ...

6 years ago | 1

| accepted

Answered
How to find x range value and calculate average of corresponding peaks in a graph signal?
Try this; index = find(y>100); % find peaks ind = find( diff(x(index)) > 0.01 ); % find ...

6 years ago | 0

| accepted

Answered
How to integrate discrete values over a surface
If your mesh if fine enough you can just multiply sides (area of rectangle) For better precision cross product can be used

6 years ago | 0

Answered
when solving Gilmore equation using ode45 , the answer comes as zero and it plots a straight line in the time interval
Here is what i tried. Do you know the result should looks like?

6 years ago | 1

| accepted

Answered
Creating a Random Vector with Several Conditions
You can just rotate circle and select points you want. I used Rodriguez formula

6 years ago | 1

Answered
Constraining a 3d plot
use interp3 to make finer mesh cut corners you want visualize using isosurface

6 years ago | 0

| accepted

Answered
Erasing part of contourf diagram (L-shaped diagram using contourf)
try ind = x_points > 2 & y_points < 2; temp(ind) = nan;

6 years ago | 0

Answered
I am new to matab. I tried to solve a non linear equation with newton raphson and modified newton raphson method but got different solution. could you please help me find the error? please note I tried to run the code in two separate files.
Plot each iteration to see what it going on fplot(f,[-5 5]) hold on for i = 1:maxiteration; % computations ... yy =...

6 years ago | 0

Answered
solve on vector equation
Try this (solution exists not for any s1 vector) function main nt = 1; ni = 2; s1 = [1 2 2]; s1 = s1/norm(s1); fun...

6 years ago | 0

| accepted

Answered
How to detect these points in red circle from point cloud. The attached data.txt is the point cloud data. Many thanks.
Here is an idea: load data.txt x = data(:,1); y = data(:,2); z = data(:,3); plot3(x,y,z,'.r') axis equal datacursormode...

6 years ago | 0

| accepted

Answered
Determine cross sectional area from patch data
I think there is no built-in function for your purpose Try to search something like THIS

6 years ago | 0

| accepted

Answered
slice plot gives black surfaces
Planes are not black. THe mesh is just too fine Add to your code h = slice(z,y,x,abs(Eg(:,:,:)),zslice,yslice,xslice); set(h,...

6 years ago | 2

| accepted

Answered
ODE solver - division by zero at time boundaries
As I see it, the problem is at t = 0, y(1,2) = 0 Can you replace 0 with 1e-3?

6 years ago | 0

| accepted

Answered
Solving a system of ODEs with conditionally defined coefficient
replace f=piecewise(0<=t<1, -2*t^2+3*t, t>=1, 1/t); with if t >= 1 f = 1/t; else f = -2*t^2+3*t; end

6 years ago | 0

| accepted

Answered
How to implement Forward Euler Method on a system of ODEs
I've tried and reached a success par_c.k = 14.39964548; % electronvolt per Angström par_c.xj = [0 0]; % position of particle j...

6 years ago | 0

| accepted

Answered
Solving two second order BVPs and the boundary conditions are related
How to set up initial guess? Any ideas? function main %-----------------------------------------------------------------------...

6 years ago | 1

| accepted

Answered
Position of elements'nodes intersected by a line
Look HERE Check each triangle/element. If intersection exists then pick/highlight this element/triangle

6 years ago | 1

| accepted

Answered
Plot dB/dt vs. time by ODE45 (with dB/dt on the y axis and time on the x axis)
What I would like to do is also plot dB/dt vs. time pvar = gradient(varsol(:,3)); dt = gradient(tsol); dB = pvar./dt; plot(t...

6 years ago | 1

| accepted

Answered
Heat transfer differential equation
Call the function this way: [t,y] = ode45(@f,[0,5],1673)

6 years ago | 0