Size mismatch (size [1 x 11] ~= size [1 x 10]).

Greetings to al my name JOSE LUIS HUAYNAY VILLAR, I have the following error problem;

Size mismatch (size [1 x 11] ~= size [1 x 10]).

the program indicates the error to me in this line, that seems strange to me

Function 'MATLAB Function3' (#169.624.635), line 21, column 17: "D(k+1)+D(j)" Launch diagnostic report.

and this is my code, please someone help me:

function dot_theta = fcn(theta,theta_0,theta_f)
dot_theta=size(10,1);
D=size(10,1);
K=size(10,1);
L=50;  %comprimento
z=linspace(0,L,10); 
theta_r = 0.218;     
alpha= 0.0115;     
K_s = 31.6;         
theta_s=0.52;      
dz=L/length(z);
b=1/(2*dz^2);
n = 2.03;
m=1-(1/n);
i=2:length(z),
j=1:length(z),
k=0:length(z),
D=(K_s*(1-m)/(alpha*m*(theta_s-theta_r)))*dot(theta,theta);
K=(K_s*(1-m)/(alpha*m*(theta_s-theta_r)))*dot(theta,theta);

dot_theta =b*((D(k+1)+D(j))*(theta(k+1)-theta(j))- b*(D(i-1)+D(j))*(theta(j)-theta(i-1))+((K(j)-K(i-1))/Delta_z));

Answer 1

[Walter Roberson]

i=2:length(z),

That is 2:10

j=1:length(z),

That is 1:10, which is one element longer than i.

D(i-1)+D(j)

D(i-1) becomes D(1 to length(z)-1) which is D(1 : 9)

D(j) is D(1:length(z)) which is D(1:10)

The two items are different lengths and cannot be subtracted.

You have similar problems for theta(k+1) vs theta(j)

[jose luis huayanay villar]

THANK YOU VERY MUCH, BUT NOW MY RESULT IS ZERO WHY?

D y K they are in another block .

function dot_theta = Richards(theta,D,K)
L=10;  %comprimento
z=linspace(0,L,5); % espaco de discretizacao
dz=L/length(z);
b=1/(2*dz^2);
i=2:length(z),
k=i-1,
j=i-2,
dot_theta=b*(D(j+1)+D(k)).*(theta(j+1)-theta(k))- b*(D(i-1)+D(k)).*(theta(k)-theta(i-1))+((K(k)-K(i-1))/dz);
dotheta=[0 0 0 0]

[Walter Roberson]

k=i-1 and j=i-2 but every time you use j you add 1 to it so j is acting in the same role as i-1 which is k. You effectively subtract theta(k)-theta(k) which is 0

[jose luis huayanay villar]

otherwise how it has to be placed, could you help me please

[Walter Roberson]

Rewrite your equations so that you never have additions of offsets, only subtractions.

Now find the greatest subtraction. The starting index for the computation must be 1 greater than that, so that after the subtraction the result is 1.

All variables that are used with less subtraction must be padded with as many leading values as needed so their first used value is at appropriate offset to be picked up by the appropriate subtraction.

For exampe, if there are offsets A(t), B(t+1) and C(t-1) then you would rewrite to (T-1), B(T-0), and C(T-2) and you would start at index max([1, 0, 2]) + 1 = 3, and A would need 1 leading padding value because at index 3, subtract 1, the first used value would be at A(2).

[jose luis huayanay villar]

Thank you very much, accommodate that way and I still have a problem

[jose luis huayanay villar]

excuse me, perform as you advised me

function dot_theta = Richards(theta,K,D,thetaz_0,thetaz_f)
L=1;  %comprimento
z=linspace(0,L,100); % espaco de discretizacao
dz=L/length(z);
b=1/(2*dz^2);
i=max([1 0 2])+1:length(z),
dot_theta=b*(D(i)+D(i-1)).*(theta(i)-theta(i-1))- b*(D(i-2)+D(i-1)).*(theta(i-1)-theta(i-2))+((K(i-1)-K(i-2))/dz);

and I got the following error. in which part have I failed?

i = Columns 1 through 15 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Columns 16 through 30 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Columns 31 through 45 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 Columns 46 through 60 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 Columns 61 through 75 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 Columns 76 through 90 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 Columns 91 through 98 93 94 95 96 97 98 99 100

Index exceeds array dimensions. Index value 99 exceeds valid range [1-98] of array D. Error in 'simulacao_julio4/MALATB Function1' (line 15) dot_theta=b*(D(i)+D(i-1)).*(theta(i)-theta(i-1))- b*(D(i-2)+D(i-1)).*(theta(i-1)-theta(i-2))+((K(i-1)-K(i-2))/dz);

[jose luis huayanay villar]

para D and K

function K = fcn(theta)
L=1;  %comprimento
z=linspace(0,L,100); % espaco de discretizacao
theta_r = 0.218;     % conteudo de agua residual
alpha= 0.0115;      %parametro de Van Genuchten 1/cm (Van Genuchten, 1980)
K_s = 31.6;         % conductividade de saturacao cm/t
theta_s=0.52;       %conteudo de agua saturado 
%dz=L/length(z);
%b=1/(2*dz);
n = 2.03;
m=1-(1/n);
i=max([1 0 2])+1:length(z),
K = K_s*(theta(i-2).^(1/2)).*(( 1-(1-(theta(i-2).^(1/m))).^m).^2);

[jose luis huayanay villar]

function D = fcn(theta)
L=1;  %comprimento
z=linspace(0,L,100); % espaco de discretizacao
theta_r = 0.218;     % conteudo de agua residual
alpha= 0.0115;      %parametro de Van Genuchten 1/cm (Van Genuchten, 1980)
K_s = 31.6;         % conductividade de saturacao cm/t
theta_s=0.52;       %conteudo de agua saturado 
n = 2.03;
m=1-(1/n);
i=max([1 0 2])+1:length(z),
D =(K_s*(1-m)/(alpha*m*(theta_s-theta_r)))*(theta(i-2).^(0.5-(1/m))./(1-(theta(i-2).^(1/m)))).*((1-(1-(theta(i-2).^(1/m))).^m).^2);

[jose luis huayanay villar]