Unable to code non linear equation in MATLAB R2013a  MATLAB giving warning message
By : Josie Moore Roy
Date : March 29 2020, 07:55 AM
This might help you There are an infinite number of solutions to this for an unspecified value of n > 3 and unknown r. I hope that it's pretty clear why – it's effectively asking for a greater and greater number of roots of (1+r)^n. You can find solutions for fixed values of n, however. Note that as n becomes larger there are more and more solutions and of course some of them are complex. I'm going to assume that you're only interested in real values of r. You can use solve and symbolic math for n = 4, n = 5, and n = 6 (for n = 6, the solution may not be in a convenient form): code :
y = 441361;
x = 66990;
n = 5;
syms r;
rsol = solve(y/x((1+r)^n1)/r==0,r,'IgnoreAnalyticConstraints',true)
double(rsol)
y = 441361;
x = 66990;
n = 5;
f = @(r)y/x((1+r).^n1)./r;
r0 = 1;
rsol = fzero(f,r0)

For loop equation into Octave / Matlab code
By : ssk
Date : March 29 2020, 07:55 AM
wish help you to fix your issue Ok, I think I finally understand your question: you are trying to find a set of phase1, phase2,..., phaseN, such that equations like the ones you describe are satisfied You know how to find y, and you supply values for freq and amp. In Matlab, such a problem would be solved using, for example fsolve, but let's look at your problem step by step.

Error in Heat Equation Matlab Code
By : Brandon K
Date : March 29 2020, 07:55 AM
wish helps you the problem is caused by the fact that M is 0, this happens because x is an array of length 0, this is due to the misuse of linspace. linspace when used as follows: linspace(x1, x2, n) generates an array of length n of equally spaced points from x1 to x2, in your case n is 0.05 and is rounded down to 0.

Optimnonlinear equation in matlab code
By : leong
Date : March 29 2020, 07:55 AM
Hope this helps So, I was having fun with this (thanks for that)! Different question, different answer. code :
function C = solve_for_F()
% Points of interest
px = 6;
py = 4.2;
% Wrapper function; search for those constants
% causing the correct X,Y intercepts (at px, py)
G = @(C) abs(F( 0, px, C)) + ... % X intercept at px
abs(F(py, 0, C)); % Y intercept at py
% Initial estimate, based on your original equation
C0 = [5/33
1247745517111813/562949953421312
4243112111277797/4503599627370496
5/66];
% Minimize the error in G by optimizing those constants
C = fminsearch(G, C0);
% Plot the solutions
plot_XY(px, py, C);
end
function plot_XY(xmax,ymax, C)
% graininess of X
N = 100;
% Find solutions for all alphae
Y = zeros(1,N);
X = linspace(0, xmax, N);
y0 = linspace(ymax, 0, N);
options = optimset('Display', 'off',...,...
'TolX' , 1e10);
% Solve the nonlinear equation for each X
for ii = 1:numel(X)
% Wrapper function for fzero()
fcn1 = @(y)F(y, X(ii), C);
% fzero() is probably the fastest and most intuitive
% solver for this problem
[Y(ii),~,flag] = fzero(fcn1, y0(ii), options);
% However, it uses an algorithm that easily diverges
% when the function slope is large. For those cases,
% solve with fminsearch()
if flag ~= 1
% In this case, the minimum of the absolute value
% is searched for (which should be zero)
fcn2 = @(y) abs(fcn1(y));
Y(ii) = fminsearch(fcn2, y0(ii), options);
end
end
% Now plot the X,Y solutions
plot(X, Y,...
'linewidth', 2,...
'color', [1 0.65 0]);
xlabel('X'), ylabel('Y')
axis([0 xmax+.1 0 ymax+.1])
end
function fval = F(Y, X, C)
% Unpack constants
b = C(1); d = C(3);
c = C(2); k = C(4);
% prework
V = atan2(2*Y, X) + c;
% Eq. 2
fval = sqrt( (b*Y*sin(V) + k*X*(cos(V) + 1))^2 + ...
(b*Y*cos(V)  k*X* sin(V) )^2 )  d;
end

How to covert this specific equation to matlab code
By : user2193383
Date : March 29 2020, 07:55 AM
Hope that helps How to represent this equation to matlab code , Like so: code :
function y = sgn(x)
if x == 0
y = 0;
else
y = x / abs(x);
end
end

