it won't run as it keeps showing illegal use of the word else

tank_diameter = 4.1;           % Diameter of the tank [meters]
total_tank_length = 20.5;      % total length of the tank [meters]
fluid_height_increment = 0.25; % increments for fluid height [meters]
safety_percent = 0.8;          % safety percent [decimal] 
 
 
%% ____________________
%% CALCULATIONS
 
tank_radius = tank_diameter/2;  % finding tank radius
Length_cylindrical_section = (total_tank_length - (2*tank_radius)); % finding length of cylindrical section 
 
% using variables A, B and C to calculate the total tank volume
A = ((pi*(tank_diameter)^2) *((3*tank_radius) - tank_diameter)/3); 
B = ((tank_radius)^2) * (acos((tank_radius -tank_diameter)/tank_radius));
C = (tank_radius) - (tank_diameter)*(sqrt((2*tank_radius*tank_diameter)- (tank_diameter)^2));
tank_volume = A+Length_cylindrical_section*(B-C);
 
% using fluid heights to find total volume tolerance 
fluid_height1 = tank_radius + (0.5*fluid_height_increment);
fluid_height2 = tank_radius - (0.5*fluid_height_increment);
 
v_tol = (tank_volume * (fluid_height1)) - (tank_volume * (fluid_height2));
 
 
for fluid_height = 0
    A = ((pi*(fluid_height)^2) *((3*tank_radius) - fluid_height)/3); 
    B = ((tank_radius)^2) * (acos((tank_radius - fluid_height)/tank_radius));
    C = (tank_radius) - (fluid_height)*(sqrt((2*tank_radius*fluid_height)- (fluid_height)^2));
    fluid_volume = A+Length_cylindrical_section*(B-C);
    
    fluid_height1 = tank_radius + (0.5*fluid_height_increment);
    fluid_height2 = tank_radius - (0.5*fluid_height_increment);
 
    v_tol = (fluid_volume * (fluid_height1)) - (fluid_volume * (fluid_height2));
    Number_loops =0;
while fluid_volume <= (tank_volume - v_tol )
      Fluid_height = fluid_height + fluid_height_increment;
      Number_loops = Number_loops +1;
else  Number_loops = Number_loops +1;
          fprintf('The final fluid volume is %.2f m^3. /n' , fluid_volume);
         
end
 disp('The number of iterations are %.0f' , Number_loops);
 disp('The safe fill volume is %.2f m^3.' , v_tol);
 disp('The final fluid volume is %.2f m^3.' , fluid_volume);
plot (fluid_volume ,fluid_height);
  xlabel = 'Fluid Height [m]';
  ylabel = 'Fluid Volume [m^3]' ;
  title = ' Fluid Volume vs Fluid Height';
end

[Ruger28]

You have a "WHILE" and an "ELSE" in a "FOR" loop with no "IF" anywhere to be found. Your syntax is wrong.

[Rik]

This time I edited your question for you. Next time, please use the tools explained on this page to make your question more readable.

[Eti Rastogi]

sorry about that and thank u

Answer 1

[Ayush Gupta]

The problem here is with the syntax of while loop, where else is being used inside while loop without using if first. Read about the documentation of while loop and how to use it, here. Refer to the following code on the changes to make:

while fluid_volume <= (tank_volume - v_tol )
      Fluid_height = fluid_height + fluid_height_increment;
      Number_loops = Number_loops +1;
%else  Number_loops = Number_loops +1;
          %fprintf('The final fluid volume is %.2f m^3. /n' , fluid_volume);   
end