Mixing
How to change number of steps of solutions with ode45 - Matlab? [closed]
$begingroup$
I have the next function:
function [f,R]=fun_z_proba(z,p,beta) % function definition
ri=0.7;
R=ri-z*(ri-1);
f=zeros(4,size(p,2));
f(1,:)=-32.*beta./(R.^4.*p(1,:));
f(2,:)=(-8*f(1,:)./R-f(1,:).*p(2,:))./p(1,:);
f(3,:)=(-p(2,:).*f(2,:)-8.*f(2,:)./R-8.*f(1,:)./(R.*R.*p(1,:))-f(1,:).*p(3,:))./p(1,:);
f(4,:)=(-f(2,:).*p(3,:)-f(3,:).*p(2,:)+8.*(-f(3,:)./R- (f(2,:)./p(1,:)-p(2,:).*f(1,:)./(p(1,:).*p(1,:)))./(R.*R)) -f(1,:).*p(4,:))./p(1,:);
end
and I am calling it with
beta=1:0.1:5;
f=cell(1,numel(beta));
ctr=1;
for beta = beta
[f{ctr},p{ctr}]=ode45(@(z,p)fun_z_proba(z,p,beta), [1 0], [1; 0; 0; 0]);
ctr=ctr+1;
end
Results important for me are stored in p, but for every value of beta I got different number of values for p. Is there some way to get the same number of p values in every case for beta, under the same conditions like here?
ordinary-differential-equations functions matlab
asked Jan 14 at 14:32
nick_namenick_name
1299
$endgroup$
closed as off-topic by Tony S.F., pre-kidney, A. Pongrácz, Riccardo.Alestra, José Carlos Santos Jan 15 at 9:34
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is not about mathematics, within the scope defined in the help center." – Tony S.F., Riccardo.Alestra, José Carlos Santos
If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
$begingroup$
I have the next function:
function [f,R]=fun_z_proba(z,p,beta) % function definition
ri=0.7;
R=ri-z*(ri-1);
f=zeros(4,size(p,2));
f(1,:)=-32.*beta./(R.^4.*p(1,:));
f(2,:)=(-8*f(1,:)./R-f(1,:).*p(2,:))./p(1,:);
f(3,:)=(-p(2,:).*f(2,:)-8.*f(2,:)./R-8.*f(1,:)./(R.*R.*p(1,:))-f(1,:).*p(3,:))./p(1,:);
f(4,:)=(-f(2,:).*p(3,:)-f(3,:).*p(2,:)+8.*(-f(3,:)./R- (f(2,:)./p(1,:)-p(2,:).*f(1,:)./(p(1,:).*p(1,:)))./(R.*R)) -f(1,:).*p(4,:))./p(1,:);
end
and I am calling it with
beta=1:0.1:5;
f=cell(1,numel(beta));
ctr=1;
for beta = beta
[f{ctr},p{ctr}]=ode45(@(z,p)fun_z_proba(z,p,beta), [1 0], [1; 0; 0; 0]);
ctr=ctr+1;
end
Results important for me are stored in p, but for every value of beta I got different number of values for p. Is there some way to get the same number of p values in every case for beta, under the same conditions like here?
ordinary-differential-equations functions matlab
asked Jan 14 at 14:32
nick_namenick_name
1299
$endgroup$
closed as off-topic by Tony S.F., pre-kidney, A. Pongrácz, Riccardo.Alestra, José Carlos Santos Jan 15 at 9:34
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is not about mathematics, within the scope defined in the help center." – Tony S.F., Riccardo.Alestra, José Carlos Santos
If this question can be reworded to fit the rules in the help center, please edit the question.
2
$begingroup$
This seems to be a question about some programming language, not a question about mathematics, right? So, maybe it should be posted to a coding site, instead?
$endgroup$
– Gerry Myerson
Jan 14 at 15:05
$begingroup$
Which one coding site?
$endgroup$
– nick_name
Jan 14 at 15:19
$begingroup$
stackoverflow.com is the coding site. "Code review" exists for improvements on working code, "scientific computing" for algorithmic questions.
$endgroup$
– LutzL
Jan 14 at 15:47
add a comment |
$begingroup$
I have the next function:
function [f,R]=fun_z_proba(z,p,beta) % function definition
ri=0.7;
R=ri-z*(ri-1);
f=zeros(4,size(p,2));
f(1,:)=-32.*beta./(R.^4.*p(1,:));
f(2,:)=(-8*f(1,:)./R-f(1,:).*p(2,:))./p(1,:);
f(3,:)=(-p(2,:).*f(2,:)-8.*f(2,:)./R-8.*f(1,:)./(R.*R.*p(1,:))-f(1,:).*p(3,:))./p(1,:);
f(4,:)=(-f(2,:).*p(3,:)-f(3,:).*p(2,:)+8.*(-f(3,:)./R- (f(2,:)./p(1,:)-p(2,:).*f(1,:)./(p(1,:).*p(1,:)))./(R.*R)) -f(1,:).*p(4,:))./p(1,:);
end
and I am calling it with
beta=1:0.1:5;
f=cell(1,numel(beta));
ctr=1;
for beta = beta
[f{ctr},p{ctr}]=ode45(@(z,p)fun_z_proba(z,p,beta), [1 0], [1; 0; 0; 0]);
ctr=ctr+1;
end
Results important for me are stored in p, but for every value of beta I got different number of values for p. Is there some way to get the same number of p values in every case for beta, under the same conditions like here?
ordinary-differential-equations functions matlab
asked Jan 14 at 14:32
nick_namenick_name
1299
$endgroup$
I have the next function:
function [f,R]=fun_z_proba(z,p,beta) % function definition
ri=0.7;
R=ri-z*(ri-1);
f=zeros(4,size(p,2));
f(1,:)=-32.*beta./(R.^4.*p(1,:));
f(2,:)=(-8*f(1,:)./R-f(1,:).*p(2,:))./p(1,:);
f(3,:)=(-p(2,:).*f(2,:)-8.*f(2,:)./R-8.*f(1,:)./(R.*R.*p(1,:))-f(1,:).*p(3,:))./p(1,:);
f(4,:)=(-f(2,:).*p(3,:)-f(3,:).*p(2,:)+8.*(-f(3,:)./R- (f(2,:)./p(1,:)-p(2,:).*f(1,:)./(p(1,:).*p(1,:)))./(R.*R)) -f(1,:).*p(4,:))./p(1,:);
end
and I am calling it with
beta=1:0.1:5;
f=cell(1,numel(beta));
ctr=1;
for beta = beta
[f{ctr},p{ctr}]=ode45(@(z,p)fun_z_proba(z,p,beta), [1 0], [1; 0; 0; 0]);
ctr=ctr+1;
end
Results important for me are stored in p, but for every value of beta I got different number of values for p. Is there some way to get the same number of p values in every case for beta, under the same conditions like here?
ordinary-differential-equations functions matlab
ordinary-differential-equations functions matlab
asked Jan 14 at 14:32
nick_namenick_name
1299
asked Jan 14 at 14:32
nick_namenick_name
1299
edited Jan 14 at 15:18
nick_name
asked Jan 14 at 14:32
nick_namenick_name
1299
asked Jan 14 at 14:32
nick_namenick_name
1299
asked Jan 14 at 14:32
nick_namenick_name
1299
1299
closed as off-topic by Tony S.F., pre-kidney, A. Pongrácz, Riccardo.Alestra, José Carlos Santos Jan 15 at 9:34
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is not about mathematics, within the scope defined in the help center." – Tony S.F., Riccardo.Alestra, José Carlos Santos
If this question can be reworded to fit the rules in the help center, please edit the question.
closed as off-topic by Tony S.F., pre-kidney, A. Pongrácz, Riccardo.Alestra, José Carlos Santos Jan 15 at 9:34
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question is not about mathematics, within the scope defined in the help center." – Tony S.F., Riccardo.Alestra, José Carlos Santos
If this question can be reworded to fit the rules in the help center, please edit the question.
2
$begingroup$
This seems to be a question about some programming language, not a question about mathematics, right? So, maybe it should be posted to a coding site, instead?
$endgroup$
– Gerry Myerson
Jan 14 at 15:05
$begingroup$
Which one coding site?
$endgroup$
– nick_name
Jan 14 at 15:19
$begingroup$
stackoverflow.com is the coding site. "Code review" exists for improvements on working code, "scientific computing" for algorithmic questions.
$endgroup$
– LutzL
Jan 14 at 15:47
add a comment |
2
$begingroup$
This seems to be a question about some programming language, not a question about mathematics, right? So, maybe it should be posted to a coding site, instead?
$endgroup$
– Gerry Myerson
Jan 14 at 15:05
$begingroup$
Which one coding site?
$endgroup$
– nick_name
Jan 14 at 15:19
$begingroup$
stackoverflow.com is the coding site. "Code review" exists for improvements on working code, "scientific computing" for algorithmic questions.
$endgroup$
– LutzL
Jan 14 at 15:47
2
2
$begingroup$
This seems to be a question about some programming language, not a question about mathematics, right? So, maybe it should be posted to a coding site, instead?
$endgroup$
– Gerry Myerson
Jan 14 at 15:05
$begingroup$
This seems to be a question about some programming language, not a question about mathematics, right? So, maybe it should be posted to a coding site, instead?
$endgroup$
– Gerry Myerson
Jan 14 at 15:05
$begingroup$
Which one coding site?
$endgroup$
– nick_name
Jan 14 at 15:19
$begingroup$
Which one coding site?
$endgroup$
– nick_name
Jan 14 at 15:19
$begingroup$
stackoverflow.com is the coding site. "Code review" exists for improvements on working code, "scientific computing" for algorithmic questions.
$endgroup$
– LutzL
Jan 14 at 15:47
$begingroup$
stackoverflow.com is the coding site. "Code review" exists for improvements on working code, "scientific computing" for algorithmic questions.
$endgroup$
– LutzL
Jan 14 at 15:47
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
If you want values at fixed locations, call the method with these locations in the place of tspan.
You could also use the dense output option to have an interpolation function over the whole interval. See Matlab documentation how to invoke it and use its result.
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
$endgroup$
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
If you want values at fixed locations, call the method with these locations in the place of tspan.
You could also use the dense output option to have an interpolation function over the whole interval. See Matlab documentation how to invoke it and use its result.
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
$endgroup$
add a comment |
$begingroup$
If you want values at fixed locations, call the method with these locations in the place of tspan.
You could also use the dense output option to have an interpolation function over the whole interval. See Matlab documentation how to invoke it and use its result.
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
$endgroup$
add a comment |
$begingroup$
If you want values at fixed locations, call the method with these locations in the place of tspan.
You could also use the dense output option to have an interpolation function over the whole interval. See Matlab documentation how to invoke it and use its result.
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
$endgroup$
If you want values at fixed locations, call the method with these locations in the place of tspan.
You could also use the dense output option to have an interpolation function over the whole interval. See Matlab documentation how to invoke it and use its result.
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
answered Jan 14 at 15:44
LutzLLutzL
58.7k42055
58.7k42055
add a comment |
add a comment |
2
$begingroup$
This seems to be a question about some programming language, not a question about mathematics, right? So, maybe it should be posted to a coding site, instead?
$endgroup$
– Gerry Myerson
Jan 14 at 15:05
$begingroup$
Which one coding site?
$endgroup$
– nick_name
Jan 14 at 15:19
$begingroup$
stackoverflow.com is the coding site. "Code review" exists for improvements on working code, "scientific computing" for algorithmic questions.
$endgroup$
– LutzL
Jan 14 at 15:47