Doubt in matlab coding

I want to get the output of this concept:

that is, if Eg>Egm

then output is Ns =5,6,7

Otherwise if Eg<Egm

output as Nb=1,2,3

else Nsb=4

I want to get corresponding N values for each condition.How to get this?

a=3;b=8;
Eg=[50 100 150 175 200 250 300];
Egm=Mean(Eg);
P=[20 15 10 5 1 0.5 0.1]
for N=1:1:7
    if Eg>Egm
        % output as Ns
    elseif Eg<Egm
        % output as Nb
    else
        %output as Nsb
        end
end

Based on this values,I want to compute following

Xs=(P(n)/a)-1;But value of P(n) is taken ony the value corresponding to Ns,that is 1,0.5,0.1

Xb=(P(n)/b)-1;But value of P(n) is taken ony the value corresponding to Nb,that is 20,15,10

Xsb=Eg; For the value Nsb

How this concept can be coded?

Answer 1

[Mathieu NOE]

hello

here you are my friend, without a for loop

a=3;b=8;
Eg=[50 100 150 175 200 250 300];
Egm=mean(Eg);
P=[20 15 10 5 1 0.5 0.1];

m = length(Eg);
Ns = find(Eg>Egm);
Nb = find(Eg<Egm);
Nsb = (1:m);
Nsb(Ns) = [];
Nsb(Nb) = [];

Xs=(P(Ns)/a)-1;
Xb=(P(Nb)/b)-1;
Xsb=Eg(Nsb);

[Ancy S G]

Ok sir.Its good and thank you.But I wanted to know how this concept go throuh a 'for loop'.Is this concept possible with for loop?

[Mathieu NOE]

sure

a=3;b=8;
Eg=[50 100 150 175 200 250 300];
Egm=mean(Eg);
P=[20 15 10 5 1 0.5 0.1];

Ns = [];
Nb = [];
Nsb = [];
        
for ci=1:length(Eg)
    if Eg(ci)>Egm
        % output as Ns
        Ns = [Ns ci];
    elseif Eg(ci)<Egm
        % output as Nb
        Nb = [Nb ci];
    else
        %output as Nsb
        Nsb = [Nsb ci];
   end
end


Xs=(P(Ns)/a)-1;
Xb=(P(Nb)/b)-1;
Xsb=Eg(Nsb);

[Ancy S G]

Thank you so much sir.Its so helpful.

[Mathieu NOE]

my pleasure !

would you mind accepting my answer ?

tx

[Ancy S G]

Sir,I have also want to compute these equations based on the above concept.Would you please answer this,how to code this equation?

Es=∑_(ci∊Ns)(〖〖Eg〗^ci - Xs〗)

Eb=∑_(ci∊Nb)(〖Xb -〖Eg〗^ci〗)

[Mathieu NOE]

hello

hope I read correctly the equations - here added at the previous code :

a=3;b=8;
Eg=[50 100 150 175 200 250 300];
Egm=mean(Eg);
P=[20 15 10 5 1 0.5 0.1];

Ns = [];
Nb = [];
Nsb = [];
        
for ci=1:length(Eg)
    if Eg(ci)>Egm
        % output as Ns
        Ns = [Ns ci];
    elseif Eg(ci)<Egm
        % output as Nb
        Nb = [Nb ci];
    else
        %output as Nsb
        Nsb = [Nsb ci];
   end
end


Xs=(P(Ns)/a)-1;
Xb=(P(Nb)/b)-1;
Xsb=Eg(Nsb);

%% Es
 Es = 0;
for k = 1:numel(Ns)
    ci = Ns(k);
    Es = Es + (Eg(ci).^ci - Xs(k));
end
Es

%% Eb
 Eb = 0;
for k = 1:numel(Nb)
    ci = Nb(k);
    Eb = Eb + (Xb(k) - Eg(ci).^ci);
end
Eb

[Ancy S G]

thank you

[Mathieu NOE]

my pleasure !

[Ancy S G]

Sir,I have one more doubt.I have to check a condition using while loop.

that is,

If X(k+1)-X(k)<=0.01 is true

then terminate

else continue

where k is the no of iterations.

a=3;b=8;
Eg=[50 100 150 175 200 250 300];
Egm=mean(Eg);
P=[20 15 10 5 1 0.5 0.1];
m = length(Eg);
Ns = find(Eg>Egm);
Nb = find(Eg<Egm);
Nsb = (1:m);
Nsb(Ns) = [];
Nsb(Nb) = [];
X=(P(Ns)/a)-1;
X=(P(Nb)/b)-1;
X=Eg(Nsb);

I want to get each iterative value.Would you please answer this?

[Mathieu NOE]

hello

sure , no problem ,

this would be the code , but it's not clear to me what iterative computation you want to do - does it has a connection to the previous code I sent to you ?

for k = 1:numel(X)-1
    dX = X(k+1)-X(k);
    if dX <=0.01
        break
    else 
        X % my computation here
    end
end

[Ancy S G]

Thank you for your valuable effort.

Sir,it's the same code.

Here Xs,Xb,Xsb in the above code,I just put it as X for all.

I want to stop this iterative process until the error between previous iterative value and new value converges nearly to zero.That is the value of X in this code.

My doubt is how to make this code as a iterative computation and the know the values of X after each iteration.

[Mathieu NOE]

hello again

I am not sure to understand how you want to have the X by iteration

the previous code (see below) is based on conditional statements (if, else,...) and I don't see how you can replace that logic with an iteration on X

maybe you can help me clarify this point

a=3;b=8;
Eg=[50 100 150 175 200 250 300];
Egm=mean(Eg);
P=[20 15 10 5 1 0.5 0.1];

Ns = [];
Nb = [];
Nsb = [];
        
for ci=1:length(Eg)
    if Eg(ci)>Egm
        % output as Ns
        Ns = [Ns ci];
    elseif Eg(ci)<Egm
        % output as Nb
        Nb = [Nb ci];
    else
        %output as Nsb
        Nsb = [Nsb ci];
   end
end


Xs=(P(Ns)/a)-1;
Xb=(P(Nb)/b)-1;
Xsb=Eg(Nsb);