Calling in a function inside a for loop and storing each answer separetly
显示 更早的评论
Hello, this is my code so far. My function outputs the number of iterations needed to solve a system, and I want to use this script to output the number of iterations but with varying a parameter as shown:
A = [-10 4 1 0; 4 -10 0 1; 1 0 -10 4; 0 1 4 -10];
B = [-200;-80;-300;-180];
n = 4;
x = [0;0;0;0];
imax = 1000;
es = 1e-6;
w= 1.2;
for w=0.1: 0.1: 1.9
engr3202_gsrelax(A,B,n,x,imax,es, w);
end
I keep getting large numbers of iterations so i'm not sure if the code is just adding them all together, but i basically want 19 outputs separately so i can plot a graph with it.
Thanks a lot!
采纳的回答
Walter Roberson
2019-11-2
编辑：Walter Roberson
2019-11-2
A = [-10 4 1 0; 4 -10 0 1; 1 0 -10 4; 0 1 4 -10];
B = [-200;-80;-300;-180];
n = 4;
x = [0;0;0;0];
imax = 1000;
es = 1e-6;
wvals = 0.1: 0.1: 1.9;
for widx = 1 : length(wvals)
w = wvals(widx);
gs(widx,:) = engr3202_gsrelax(A,B,n,x,imax,es, w);
end
plot(wvals, gs)
3 个评论
Nadine Nassar
2019-11-2
Walter Roberson
2019-11-2
We do not know the size of your output for each call. Using the colon allows for the possibility that you return a vector for each call.
Nadine Nassar
2019-11-2
更多回答（1 个）
You have not provided the output varibles of the function engr3202_gsrelax(A,B,n,x,imax,es, w);
Make output variables in the calling, I assume only one variable here, say output and intialize with length of w
A = [-10 4 1 0; 4 -10 0 1; 1 0 -10 4; 0 1 4 -10];
B = [-200;-80;-300;-180];
n = 4;
x = [0;0;0;0];
imax = 1000;
es = 1e-6;
w= 1.2;
w=0.1: 0.1: 1.9;
output = zeros(1, length(w));
for iw=0.1: 0.1: 1.9
output(:, iw) = engr3202_gsrelax(A,B,n,x,imax,es, iw);
end
You can get the data in the variable output for all your loop iterations(19 in our case)
4 个评论
Walter Roberson
2019-11-2
Now, this will not work. You are trying to use the non-integer iw as an index into output(). And
length(w=0.1: 0.1: 1.9)
is not valid syntax.
Bhaskar R
2019-11-2
Yes, I corrected now. Thanks
Nadine Nassar
2019-11-2
Nadine Nassar
2019-11-2
类别
在 帮助中心 和 File Exchange 中查找有关 Creating and Concatenating Matrices 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
