Vector length error in code

Question

Kailin Johnsson 2020-11-12

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/646153-vector-length-error-in-code

评论： Kailin Johnsson 2020-11-12

Hello,

I am trying to run a simple code, and I am having a problem with vector lenght. I went back and counted all my data points and made sure each point was equal to 8.. perhaps I am missing something?

% Plot all models 1790-1860

%Malthusian Growth Model

% Time interval

% t = (1790:10:1860)';

% Previous population

Pn = [2.913 3.929 5.308 7.239 9.638 12.866 17.069 23.191]';

% Growth Rate Assumption

R = (0.349+1)';

%Malthusian Model

E = (Pn*R)';

% Discrete Logistic Model

% Parameter and intial condtions

r= (0.349);

% Carrying Capactiy

M= 330.0;

X0= 3.929;

p= [3.929 5.308 7.239 9.638 12.866 17.069 23.191 31.443]';

% For loop to generate seqeunce terms

for i=1:length(p)

F(i)=p(i)+r*p(i)*(1-p(i)/M)';

end

tBegin = 1790; % time begin

tEnd = 1860; % time end

%Gompertz Model

% Time Interval

% a=(1790:10:1860)';

% Population

b= [3.929 5.308 7.239 9.638 12.866 17.069 23.191 31.443]';

Data = b;

k2 = 330.0;

B = log(Data(2:8,1)./k2);

A = log(Data(1:7,1)./k2);

X = A\B;

b = -log(X(1,1));

P0 = Data(1,1);

LL = zeros(8,1);

LL(1,1) = P0;

for i = 2:8

LL(i,1) = exp((exp(-b)).*log(LL(i-1,1))+((1-exp(-b)).*log(k2)));

end

% Single Plot

% figure

% plot(Labels,Data,'b-*',Labels,PG,'r-*')

% title('Gompertz Model, 1790-1860')

% legend('Data','Model','Location','northwest')

% hold on

%R2

SST = sum((Data-mean(Data)).^2);

SSE = sum((Data-LL).^2);

R2 = 1- (SSE/SST)

R2 = 0.9816

% Beverton-Holt Model

% Parameter and intial condtions

Pe= 486.8

Pe = 486.8000

a1= 1.23065

a1 = 1.2307

b2= 2110.5

b2 = 2.1105e+03

p3= [3.929 5.308 7.239 9.638 12.866 17.069 23.191 31.443]';

% Bevholt equation

E4 = a1*(p3)./(1+(p3/b2))

E4 = 8×1

4.8262 6.5159 8.8782 11.8071 15.7376 20.8374 28.2298 38.1273

% Time Interval

% a=(1790:10:1860)';

% Population

b= [3.929 5.308 7.239 9.638 12.866 17.069 23.191 31.443]';

Data = b;

Labels2 = [1790:10:1860]';

Labels = [1790:10:2010]';

% Plot all models 1790-1860

figure

plot(Labels2,Data,'k-*',Labels2,E,'r-*',Labels2,F,'b-*',Labels2,LL,'m-*',Labels2,E4,'g-*')

title('US Population Data, 1790-1860')

legend('Data','Malthusian','Discrete Logistic','Gompertz','Beverton-Holt Model')

ylabel('Population (Millions)');

xlabel ('Years')

axis([1780 1860 0 200])

hold on

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Answer 1

Cris LaPierre 2020-11-12

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/646153-vector-length-error-in-code#answer_542838

编辑：Cris LaPierre 2020-11-12

What line is causing your trouble? I just ran the code you shared and did not get any errors.

Best to copy/paste the entire error message (all the red text) instead of summarizing it.

Perhaps you have a variable in your workspace that is causing some trouble. Try clearning your workspace (they clear in your command window and press enter) and then run your code again.