myfunction not working when applied on a meshgrid

2 次查看（过去 30 天）
Moufid Tarek
Moufid Tarek 2022-11-27
回答： Torsten 2022-11-27
I am absolute beginner in Matlab, and I have a function that solves the kepler equation via newton's method (iterations), that works 100% correctly when I manually input argument, but when I try to apply it on a meshgrid elements, it doesn't work, I tried multiple solutions but to no avail.
the function in kepler.m
function [E_n,i_iter] = kepler(M_an,ecc_1)
f=@(E) M_an - E + (ecc_1*sin(E));
df= @(E) -1 + (ecc_1*cos(E));
error=0;
E0=0;
i=0;
while error > (10^-6)
E1= E0- (f(E0)/df(E0));
error = abs(E1-E0);
E0=E1;
i=i+1;
end
E_n=E1;
i_iter=i;
the script file with the grid
x= 0:0.01:2*pi; %629 element.
y= 0:0.001:1; %1001 element.
[X, Y]= meshgrid(x,y);
z=zeros(1001,629); %% for X and Y are both displayed 1001x629 double in the workspace.
z=kepler(X,Y); % it is here where it doesnt work.
% tried
% for i=0:1001
% for j=0:629
% z(i,j)=(kepler(X(i,j),Y(i,j)));
% end
% end
when I do as in the code above I have the message
Warning: Rank deficient, rank = 1, tol =5.574419e-12.
> In kepler (line 9)
In untitled2 (line 6)
when I try the commented code I get :
Index in position 1 is invalid. Array indices must be positive integers or logical values.
Error in untitled2 (line 11)
z(i,j)=(kepler(X(i,j),Y(i,j)));
Thank you in advance for your help.

请先登录，再回答此问题。

采纳的回答

Torsten
Torsten 2022-11-27
x= 0:0.01:2*pi; %629 element.
y= 0:0.001:1; %1001 element.
[X, Y]= meshgrid(x,y);
z=zeros(1001,629); %% for X and Y are both displayed 1001x629 double in the workspace.
for i=1:1001
for j=1:629
[z(i,j),~]=kepler(X(i,j),Y(i,j));
end
end
function [E_n,i_iter] = kepler(M_an,ecc_1)
f = @(E) M_an - E + (ecc_1*sin(E));
df = @(E) -1 + (ecc_1*cos(E));
error = 1;
E0 = 0;
i = 0;
while error > (10^-6)
E1 = E0 - f(E0)/df(E0);
error = abs(E1-E0);
E0 = E1;
i = i+1;
end
E_n = E1;
i_iter = i;
end

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Language Fundamentals 的更多信息

标签

产品


版本

R2021b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by