How to compare elements in an array?

My for loop cycles through a series of initial CL values and then a lot of calculations are done and I get final values for CL "CL_IC2." I want to see if any of the original CL values are equal to their corresponding CL_IC2 values.

clc;
clear;

%Design Mission
PAX = 250;

Cargo = 8000;
Range = 7000; %N. Miles
DRatio = .9524988;
PRatio = .23590495;
M = .85;
Vapp = 145; %Knots
TOFL = 10500; %Feet
a = 576.4592054; % Speed of Sound at 35,000 ft, KNOTS
V_cr = M*a; %Knots
R_all = Range + 200 + V_cr*.75; % n.miles

% Fuel Fraction for JT8D Engine with "R_all"
WfWto_8D = .49;
C_JT8D = .78; % SFC JT8D
C_JT9D = .61; % SFC JT9D
WfWto_9D = WfWto_8D*(C_JT9D/C_JT8D);
XX = .7; % Percent Max Fuel at Landing
%%%%%%%Values Changed Manually %%%%%%%%%
Abreast = 8; % Tested 4 - 8
N_aisle = 1; % Tested 1 & 2
Sweep = 30; % Degrees, Tested: 25, 30, 35, 40
AR = 8;     % Tested: 6-9
Airfoil = 1; % Supercritical = 1, Conventional = 2.

% Assuming a Cl value so need a for loop. 
CL=[.45:.01:.58];
n = length(CL);
DelM = cell(1,[]);

syms x
syms y
for i= 1:n

    if Airfoil == 1 % Supercritical
        DelM{i} = vpasolve((CL(i)==((-2*10^9)*x^6)-((1*10^8)*x^5)-((2*10^6)*x^4)-((2632.1*x^3)+124.37*x^2)-(5.8637*x)+.5475),x,[-.01 .015]);
    end

    if Airfoil == 2 %Conventional
        DelM{i} = vpasolve((CL(i)==(-5.1087*x^2)-(2.9657*x)+.5509),x,[-.02 .04]);
    end
     NewDelM=cell2sym(DelM,'f');
     MDiv=(M+.004)-NewDelM; 

     if Airfoil == 1
         if Sweep == 25
             %tc(i) = solve((y == (135.46.*(MDiv(i)).^4)-(449.48.*(MDiv(i)).^3)+(561.45.*(MDiv(i)).^2)-(313.45.*MDiv(i))+66.196),y);
              tc(i) = solve((y == (3.7229.*(MDiv(i)).^2)-(6.7143.*MDiv(i))+3.1025));
         end

         if Sweep == 30
             %tc(i) = solve((y == (339.86.*(MDiv(i)).^4)-(1139.2.*(MDiv(i)).^3)+(1434.1.*(MDiv(i)).^2)-(804.35.*MDiv(i))+169.83),y);
             tc(i) = solve((y == (3.9755.*(MDiv(i)).^2)-(7.3602.*MDiv(i))+3.4805));
         end  

         if Sweep == 35
             %tc(i) = solve((y == (1098.2.*(MDiv(i)).^4)-(3728.7.*(MDiv(i)).^3)+(4751.1.*(MDiv(i)).^2)-(2693.7.*MDiv(i))+573.67),y);
              tc(i) = solve((y == (6.2186.*(MDiv(i)).^2)-(11.535.*MDiv(i))+5.43));
         end

         if Sweep == 40
             %tc(i) = solve((y == (13.242.*(MDiv(i)).^2)-(24.825.*MDiv(i))+11.718),y);
             tc(i) = solve((y == (13.242.*(MDiv(i)).^2)-(24.825.*MDiv(i))+11.718));
         end
     end

     if Airfoil == 2
         if Sweep == 25
             tc(i) = solve((y == (-.5307.*MDiv(i))+.5181),y);
         end

         if Sweep == 30
             tc(i) = solve((y == (-.5037.*MDiv(i))+.5051),y);
         end  

         if Sweep == 35
             tc(i) = solve((y == (-.4671.*MDiv(i))+.4854),y);
         end

         if Sweep == 40
             tc(i) = solve((y == (-.4267.*MDiv(i))+.4632),y);
         end
     end

     Par = (cosd(Sweep)^2).*((tc).^2)*AR;

     % Need the low speed CL_max_to and CL_max_ld. Use Figure 3 with "Par."
     CL_TO(i) = solve((y == (-30.959.*(Par(i).^2))+12.965.*(Par(i))+1.1735),y);
     CL_LD(i) = solve((y == (-23.26.*(Par(i).^2))+11.166.*(Par(i))+2.1806),y);

     % Landing Wing Loading
     WS_LD(i) = ((Vapp/1.3)^2).*(CL_LD(i))*(DRatio/296);
     %Takeoff Wing Loading
     WS_TO(i) = (WS_LD(i)./(1-(XX*WfWto_9D))); 
     % Initial Cruise Wing Loading
     WS_IC = .965.*WS_TO;
     % Initial Cruise CL
     CL_IC = (WS_IC./(1481*PRatio*((M)^2)));
     CL_IC1 = double(CL_IC);
     CL_IC2 = round(CL_IC1,3)

     %if CL(i) == CL_IC2
      %  CL_f = CL

     %else
     %    CL_f = 0
     %end
     end

%end

You don't really need to worry about the middle just right before the for loop starts and the last few lines. Thank you.

Answer 1

[Prajit T R]

Hi Alec

You can use the 'find' function to obtain the values which are common between two arrays. For example:

a=[1 2 3 4]
b=[5 2 3 7]
find(a==b)

The above code returns:

ans =

     2     3

In your case, this would be find(CL==CL_IC2)

I hope this helps.

Cheers

[Alec Carruthers]

Alright, I will try that.

Thanks, Alec