EMHPM plot function by multisteps

Question

Jose Sosa Lopez 2020-2-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/504964-emhpm-plot-function-by-multisteps

评论： Jose Sosa Lopez 2020-2-14

Hello, could you help me to know how can I plot this kind of function, I want to plot by steps, the value of Y when t=0, t=0.1, t=0.2, and so on, but using in the next Y the value of the previous one.

The function that I did is:

clear all; clc;

t=0;

T=0;

c=1;

yi0=c;

while t<=(10)

t

yi1=(T/1)*(yi0*-exp(t)*yi0*yi0);

yi2=(T/2)*(yi1*exp(t)-exp(t)*yi1*yi0);

yi3=(T/3)*(yi2*exp(t)-exp(t)*yi2*yi1);

Y=yi0+yi1+yi2+yi3;

yi0=Y

plot (t,Y) %(I dont know how to plot it)

t=t+0.1;

T=0.1;

end

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Jose Sosa Lopez 2020-2-14

在 MATLAB Online 中打开

yes, Thank you. That's what I was looking for.

I also solve it, although I mistake in the equation, but I agree with your answer.

Thanks for your time.

clear all; clc; close all;
T=0;
c=1;
yi0=c;
t=linspace(0,10,101); Y=t;
Y(1)=yi0;
T=0.1;
for ite=2:101
% % % for t=0:5
    yi1=(T/1)*(yi0-exp(t(ite))*yi0^2);
    yi2=(T/2)*(yi1-exp(t(ite))*yi1*yi0);
    yi3=(T/3)*(yi2-exp(t(ite))*yi2*yi1);
    Y(ite)=yi0+yi1+yi2+yi3;
    yi0=Y(ite);
end
plot(t,Y','--')
hold on
t=linspace(0,10,101);
yinicial = 1;
[t,y] = ode45(@(t,y) y-(exp(t))*y^2, t, yinicial);
plot (t,y)
hold off

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Answer 1

Payas Bahade 2020-2-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/504964-emhpm-plot-function-by-multisteps#answer_415555

在 MATLAB Online 中打开

Hi Jose,

I have used array ‘tp’ and ‘Yp’ to store values of ‘t’ and ‘Y’ respectively for evey time step and used it to make the final plot. Below mentioned is the modified code:

t=0;
T=0;
c=1;
yi0=c;
i=1;
while t<=10
    tp(i)=t; % storing t values 
    yi1=(T/1)*(yi0*-exp(t)*yi0*yi0);
    yi2=(T/2)*(yi1*exp(t)-exp(t)*yi1*yi0);
    yi3=(T/3)*(yi2*exp(t)-exp(t)*yi2*yi1);
    Y=yi0+yi1+yi2+yi3;
    yi0=Y;
    Yp(i)=Y; % storing Y values
    t=t+0.1;
    T=0.1;
    i=i+1;
end
plot(tp,Yp) % plotting all t and Y values
xlabel('t')
ylabel('Y')