if function error, here i want MatLab to find the values of V5L that are between 1 and 4.5 and name it V, and use it in another upcoming equation

clear,clc,clf
Q=3.3;
D5L=[12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254]
    V5L=((4.*Q)./(pi.*D5L.^2));
    if V5L > 1 & V5L < 4.5
        V=V5L
    end
Do=((4.*Q)./(pi.*V)).^(0.5)

[omar mahallawy]

please note that there should be 13 V that are within range of 1 and 4.5 therefor 13 Do

Answer 1

[Star Strider]

This works for me:

Q = 3.3;
D5L = [12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254];
V5L = ((4.*Q)./(pi.*D5L.^2));
V = V5L((V5L > 1) & (V5L < 4.5));
Do = sqrt((4.*Q)./(pi.*V))

producing:

Do =
    1.0160    1.0668    1.1176    1.1684    1.2192    1.3208    1.4224    1.5240    1.6256    1.7272    1.8288    1.9304    2.0320

EDIT — (27 Jan 2019 at 15:09)

This runs for me without error (in R2018b):

Q=3.3;
%gamma=8.43 kN/m3 = 859.62076503 Kg/m3 (*1000/9.81)
rouh=859.62076503;
g=9.81;
Gamma=(rouh.*g);
Zs=0;
Ze=0;
L=1285000;
Ks=(0.000045);
Er=(1E-8);
viscosity=(3.83.*1E-3);
% material grade X70
strength= 482000000;
%API 5L
% % D5L=[12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254]
% % V5L=((4.*Q)./(pi.*D5L.^2));
% % if V=V5L(V5L > 1 & abs(V5L - 4.5<1e-5));
% % end
% % Do=((4.*Q)./(pi.*V)).^(0.5)
D5L = [12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254];
V5L = ((4.*Q)./(pi.*D5L.^2));
V = V5L((V5L > 1) & (V5L < 4.5));
Do = sqrt((4.*Q)./(pi.*V));

Re=(V.*Do./viscosity);
Fo=0.01;
for I=0:1:1E6;
    Fn=(1./(-4.*log10((Ks./(3.71.*Do))+((1.26)./(Re.*sqrt(Fo)))))).^2;
    E=abs((Fn-Fo)/Fn);
    if  E<=Er;
        Fn=Fn(end);
        display(E)
        break
    end
    if E>Er;
        Fo=Fn;
    end
end
Hloss=((Fn.*L.*Q.^2)./(12.*Do.^5));
Hpump=Hloss+Ze-Zs;
%calculating Hloss every 128500M
LC=1:128500:1285000;
for i=1:1:length(LC);
    Hpump=Hloss+Ze-Zs;
    PRESSURE=rouh.*g.*Hpump.*1E-5;
    numberofpumps=ceil(PRESSURE./90);
    pressureperpump=(PRESSURE./numberofpumps);
    HlossN=((Fn.*LC(i).*Q.^2)./(12.*sqrt(Do)));
    TEL(i,:)=(Hpump-HlossN+Zs);
    HGL(i,:)=(TEL(i,:)-((V.^2)./(2.*g)));
    PE=Gamma.*(HGL-Ze);
    T=((PE(i).*Do)./(2.*strength));
end
for ii=1:1:length(Do)
    subplot(4,4,ii)
    plot(LC,TEL(:,ii))
    hold on
    plot(LC,HGL(:,ii))
    xlabel('LC')
    ylabel('HGL & TEL')
end

[omar mahallawy]

the error was on my side.

thank you so much for your help

[Star Strider]

As always, my pleasure.

Answer 2

[madhan ravi]

EDITED

clear all
Q=3.3;
D5L=[12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254]
V5L=((4.*Q)./(pi.*D5L.^2));
V=V5L(V5L > 1 & V5L < 4.5);
Do=((4.*Q)./(pi.*V)).^(0.5);

[omar mahallawy]

The expression to the left of the equals sign is not a valid target for an assignment

[madhan ravi]

Upload the full code that your trying here.

[omar mahallawy]

clear,clc,clf

format short

Q=3.3;

%gamma=8.43 kN/m3 = 859.62076503 Kg/m3 (*1000/9.81)

rouh=859.62076503;

g=9.81;

Gamma=(rouh.*g);

Zs=0;

Ze=0;

L=1285000;

Ks=(0.000045);

Er=(1.*10.^-8);

viscosity=(3.83.*10.^-3);

% material grade X70

strength= 482000000;

%API 5L

D5L=[12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254]

V5L=((4.*Q)./(pi.*D5L.^2));

if V=V5L(V5L > 1 & abs(V5L - 4.5<1e-5));

end

Do=((4.*Q)./(pi.*V)).^(0.5)

Re=(V.*Do./viscosity)

Fo=0.01;

for I=0:1:10^6;

Fn=(1./(-4.*log10((Ks./(3.71.*Do))+((1.26)./(Re.*sqrt(Fo)))))).^2;

E=abs((Fn-Fo)/Fn);

if E<=Er;

Fn=Fn(end),display(E),break,

end

if E>Er;

Fo=Fn;

end

end

Hloss=((Fn.*L.*Q.^2)./(12.*Do.^5))

Hpump=Hloss+Ze-Zs

%calculating Hloss every 128500M

LC=1:128500:1285000;

for i=1:1:length(LC);

Hpump=Hloss+Ze-Zs

PRESSURE=rouh.*g.*Hpump.*10.^(-5)

numberofpumps=ceil(PRESSURE./90)

pressureperpump=(PRESSURE./numberofpumps)

HlossN=((Fn.*LC(i).*Q.^2)./(12.*Do.^5))

TEL(i,:)=(Hpump-HlossN+Zs)

HGL(i,:)=(TEL(i,:)-((V.^2)./(2.*g)))

PE=Gamma.*(HGL-Ze)

T=((PE(i).*Do)./(2.*strength))

end

for ii=1:1:length(Do)

subplot(4,4,ii)

plot(LC,TEL(:,ii))

hold on

plot(LC,HGL(:,ii))

xlabel('LC')

ylabel('HGL & TEL')

end

[madhan ravi]

clear,clc,clf
format short
Q=3.3;
%gamma=8.43 kN/m3 = 859.62076503 Kg/m3 (*1000/9.81)
rouh=859.62076503;
g=9.81;
Gamma=(rouh.*g);
Zs=0;
Ze=0;
L=1285000;
Ks=(0.000045);
Er=(1.*10.^-8);
viscosity=(3.83.*10.^-3);
% material grade X70
strength= 482000000;
%API 5L
D5L=[12.75*0.0254 14*0.0254 16*0.0254 18*0.0254 20*0.0254 22*0.0254 24*0.0254 26*0.0254 28*0.0254 30*0.0254 32*0.0254 34*0.0254 36*0.0254 38*0.0254 40*0.0254 42*0.0254 44*0.0254 46*0.0254 48*0.0254 52*0.0254 56*0.0254 60*0.0254 64*0.0254 68*0.0254 72*0.0254 76*0.0254 80*0.0254]
V5L=((4.*Q)./(pi.*D5L.^2));
V=V5L(V5L > 1 & abs(V5L - 4.5<1e-5));
Do=((4.*Q)./(pi.*V)).^(0.5)
Re=(V.*Do./viscosity)
Fo=0.01;
for I=0:10^6
    Fn=(1./(-4.*log10((Ks./(3.71.*Do))+((1.26)./(Re.*sqrt(Fo)))))).^2;
    E=abs((Fn-Fo)/Fn);
    if  E<=Er
        Fn=Fn(end);
        display(E)
        break
    else 
        Fo=Fn;
    end
end
Hloss=((Fn.*L.*Q.^2)./(12.*Do.^5));
Hpump=Hloss+Ze-Zs;
%calculating Hloss every 128500M
LC=1:128500:1285000;
TEL=zeros(numel(LC),numel(Do));
HGL=zeros(numel(LC),numel(Do));
PE=zeros(numel(LC),numel(Do));
T=zeros(numel(LC),numel(Do));
for k=1:numel(LC)   
    HlossN=((Fn.*LC(k).*Q.^2)./(12.*Do.^5));
    TEL(k,:)=(Hpump-HlossN+Zs);
    HGL(k,:)=(TEL(k,:)-((V.^2)./(2.*g)));
    PE(k,:)=Gamma.*(HGL(k,:)-Ze);
    T(k,:)=((PE(k,:).*Do)./(2.*strength));
end
for ii=1:numel(Do)
    subplot(4,4,ii)
    plot(LC,TEL(:,ii))
    hold on
    plot(LC,HGL(:,ii))
    xlabel('LC')
    ylabel('HGL & TEL')
end