Problem with if and else and else

Dear all,

I have a problem which i despiratly need an help with.

The idea I am think of is a suituation were if the first if statment is ok trhen the porgram stop however if the condition is not met, it moves to the next which i represent here with elseif and so on till the last elseif ststment.

Please I will appreaciate all contribution

if (0.04<=t_1/Do<0.05) % If condition

t_1 = Pd*di/(2*k*Fy) % Determine the minimum thickness

Do = di + 2*t_1 % Define the external diameter

elseif (0.04<=t_2/D1<0.05) % Elseif condition for the second round

t_2 = (Pd-Pe)*D1/2*k*Fy %Determine the minimum thickness

D1 = di + 2*t_2 %Define the external Diameter

elseif (0.04<=t_3/D2<0.05) %elseif condition for the final round

t_3 = D2/(((4*Fy)/(Y_sc*Ym*(Pd-Pe)*sqrt(3))) + 1) %Determine the minimum thickness

D2 = di + 2*t_3 %Define the external Diameter

end

Answer 1

[David Hill]

if 0.04<=t_1/Do&&t_1/Do<0.05                   %need &&
    t_1 = Pd*di/(2*k*Fy);                      
    Do = di + 2*t_1;                               
elseif 0.04<=t_2/D1&&t_2/D1<0.05             
    t_2 = (Pd-Pe)*D1/2*k*Fy;                 
    D1 = di + 2*t_2;                                 
elseif 0.04<=t_3/D2&&t_3/D2<0.05              
    t_3 = D2/(((4*Fy)/(Y_sc*Ym*(Pd-Pe)*sqrt(3))) + 1);       
    D2 = di + 2*t_3;                                     
end

[joshua Abam]

Hi David,

sorry can you help by point me to the right direct as if statement is not giving the right answer

it borders on the same challenge

Thanks

to = Pli*di/(2*k*Fy) % Determine the minimum thickness

Do = di + 2*t_1 % Define the external diameter

0.04<=to/Do&&to/Do<0.05 % If condition

% if logical true disp(Do) and disp(to) ortherwise continue

t_2 = (Pli-Pe)*Do/2*k*Fy % Determine the minimum thickness

D_2 = di + 2*t_2 % Define the external Diameter

0.04<=t_2/D_2&&t_2/D_2<0.05 % Elseif condition for the second round

% if logical true disp(D_2) and disp(t_2) ortherwise continue

t_3 = Do/(((4*Fy)/(Y_sc*Ym*(Pli-Pe)*sqrt(3))) + 1) % Determine the minimum thickness

D_3 = di + 2*t_3 % Define the external Diameter

0.04<=t_3/D_3&&t_3/D_3<0.05 % elseif condition for the final round

% if logical true disp(D_3) and disp(t_3) ortherwise display not true

%and if logical true it should use in the next equation

%let say

x = D; %Let say D is the outcome from the logical statment

%That is now substituted into the equation below to below

% Bursting Criteria from Numerical Analysis of DNV-OS-F201

(Pli-Pe)*Y_sc*Ym - 4*f_min*(0.5*(x)-0.127)/(sqrt(3)*(x)-(0.5*(x)-0.127))<=0