must return a column vector

code:

function dy = phy_ode_1(t,y)
dy = zeros(length(y),1);
const=0.5;
sp=-0.5:0.5:14.5;
top=0;
p_crit=sp+top;
 
dy=const*(y-p_crit);
end

call fun:

[t,y]=ode45('phy_ode_1',0:0.5:10,35)

i got erro, must return column vector. could you help me?

Answer 1

[Alan Stevens]

Do you want something like this

sp=-0.5:0.5:14.5;

for i = 1:length(sp)
[t,y(:,i)]=ode45(@(t,y) phy_ode_1(t,y,sp(i)),0:0.5:10,35);
end

plot(t,y)

function dy = phy_ode_1(~,y,sp)

const=0.5;

top=0;
p_crit=sp+top;
 
dy=const*(y-p_crit);
end

[gnanaguru murugan]

Thank you for your reply.

this is another function called recruitment. i have to plot betwwen recruitment and phy_ode_1.

function voltot2 = recruitment(PIP,PEEP,opmin,opmax)

A = 0.0072;

B = 0.0072;

K = 0.15;

voltot2=[];

open=[];

voltot=0;

lung_level_units=9000;

for i=1:length(PIP)

for pressure=PEEP:PIP

for SP = -0.5:0.5:14.5

for TOP = opmin:opmax

if opmin == 0 || opmin == opmax

TOP = opmax;

end

if pressure > (SP+TOP)

volm = A-B*exp(-K*(PIP-SP));

vol = volm*lung_level_units/(1+opmax-opmin);

else

vol = 0;

end

voltot = voltot+vol;

end

end

voltot2(end+1)=voltot;

end

end

call fn:

sp=-0.5:0.5:14.5;

PIP=35;

PEEP=0;

opmin=0;

opmax=0;

for i = 1:length(sp)

[t,y(:,i)]=ode45(@(t,y) phy_ode_1(t,y,sp(i)),0:0.5:10,35);

p=y(:,i);

vol=recruitment(PIP,PEEP,opmin,opmax);

plot(p,vol')

end

I got error vector must be same length. from workspace P=21*1, vol=1*36.

could you help me. Thanks a lot

Answer 2

[gnanaguru murugan]

Thank you for your reply.

this is another function called recruitment. i have to plot betwwen recruitment and phy_ode_1.

function voltot2 = recruitment(PIP,PEEP,opmin,opmax)

A = 0.0072;

B = 0.0072;

K = 0.15;

voltot2=[];

open=[];

voltot=0;

lung_level_units=9000;

for i=1:length(PIP)

for pressure=PEEP:PIP

for SP = -0.5:0.5:14.5

for TOP = opmin:opmax

if opmin == 0 || opmin == opmax

TOP = opmax;

end

if pressure > (SP+TOP)

volm = A-B*exp(-K*(PIP-SP));

vol = volm*lung_level_units/(1+opmax-opmin);

else

vol = 0;

end

voltot = voltot+vol;

end

end

voltot2(end+1)=voltot;

end

end

call fn:

sp=-0.5:0.5:14.5;

PIP=35;

PEEP=0;

opmin=0;

opmax=0;

for i = 1:length(sp)

[t,y(:,i)]=ode45(@(t,y) phy_ode_1(t,y,sp(i)),0:0.5:10,35);

p=y(:,i);

vol=recruitment(PIP,PEEP,opmin,opmax);

plot(p,vol')

end

I got error vector must be same length. from workspace P=21*1, vol=1*36.

could you help me. Thanks a lot