# Unable to perform assignment because the size of the left side is 2-by-1 and the size of the right side is 1-by-3.

5 views (last 30 days)
Felix Cazarez on 9 Jul 2020
Edited: Matt J on 9 Jul 2020
Hola, este es mi codigo y me da el error del titulo, las funciones las tengo abiertas en las pestañas de a los lados, alguien puede ayudarme?
clear clc;
reply = input('Introduce el numero de ejercicio que deseas graficar? (1,2,3,4,5): ','s');
t=-2:0.01:2;
x=zeros(2,length(t));
dx=zeros(2,length(t));
t=-10:0.001:10;
x=zeros(3,length(t));
dx=zeros(3,length(t));
else
disp('Ese numero no coincide con ninguna de las opciones,')
hold on
for i=1:length(t)
x(:,i)=fun1(t(i));
dx(:,i)=fun1d(t(i));
end
hold on
for i=1:length(t)
x(:,i)=fun2(t(i));%grafica sin derivar la fucion del ejercicio 1
dx(:,i)=fun2d(t(i));%grafica la funcion derivada del ejercicio 1
end
hold on
for i=1:length(t)
x(:,i)=fun3(t(i));
dx(:,i)=fun3d(t(i));
end
hold on
for i=1:length(t)
x(:,i)=fun4(t(i));
dx(:,i)=fun4d(t(i));
end
hold on
for i=1:length(t)
x(:,i)=fun5(t(i));
dx(:,i)=fun5d(t(i));
end
end
end
subplot(2,1,1)
plot(x(1,:),x(2,:))%Con esta imprimimos 2 dimensiones
title('Grafica de la función vectorial sin derivar')
xlabel('f(t)')
ylabel('g(t)')
grid on
subplot(2,1,2)
plot(dx(1,:),dx(2,:))
title('Grafica de la función vectorial derivada')
xlabel('df/dt')
ylabel('dg/dt')
grid on
subplot(2,1,1)
plot3(x(1,:),x(2,:),x(3,:))% con esto imprimos para 3 componentes
title('Grafica de la función vectorial sin derivar')
xlabel('f(t)')
ylabel('g(t)')
zlabel('h(t)')
grid on
subplot(2,1,2)
plot3(dx(1,:),dx(2,:),dx(3,:))
title('Grafica de la función vectorial derivada')
xlabel('df/dt')
ylabel('dg/dt')
zlabel('dh/dt')
grid on
else
disp('por lo tanto no se creara ninguna grafica, vuelve a intentarlo.')
end

Matt J on 9 Jul 2020
Edited: Matt J on 9 Jul 2020
This error message results from doing something like this:
>> x=rand(2,3);
>> x(:,1)=[4,5,6]
Unable to perform assignment because the size of
the left side is 2-by-1 and the size of the right side is 1-by-3.
Clearly, this is wrong because the size of x(:,1) is 2x1 and the thing you are trying to assign into it is a different size, 1x3.
Matt J on 9 Jul 2020
To tell you how to fix it, you would first have to tell me what fun5 should return (what is the size of the correct output) and also what the size of x is supposed to be when the code is working correctly. This lines makes it look like the output of funS will always be 1x3,
r=[ft,gt,ht];
wherease x(:,i) can never be 1x3. It will always be a 2x1 or 3x1 column vector.