i have a problem connecting 5 dots together using the plot fuction. i should have two parrallel lines but i get a blank sheet

1 次查看（过去 30 天）
omar mahallawy
omar mahallawy 2018-12-8
编辑： Cris LaPierre 2018-12-11
clear,clc,clf
format long
Q=0.03;
rouh=847;
g=9.81;
Gamma=(rouh.*g);
Zs=0;
Ze=0;
L=500;
Ks=(6*10.^-5);
viscosity=(1.1*10.^-6);
V=1.34:0.5:4.5
for I=1
D=sqrt(((4.*Q))./(V.*pi))
end
Re=(V.*D./viscosity);
Er=(1.*10.^-8);
Fo=0.01;
for I=0:1:10^6;
Fn=(1./(-4.*log10((Ks./(3.71.*D))+((1.26)./(Re.*sqrt(Fo)))))).^2;
E=abs((Fn-Fo)/Fn);
if E<=Er;
display(Fn),display(E),break,
end
if E>Er;
Fo=Fn;
end
end
Hloss=((Fn.*L.*Q.^2)./(12.*D.^5))
Hpump=Hloss
%calculating Hloss every 100M
Hloss=((Fn.*L.*Q.^2)./(12.*D.^5))
Hpump=Hloss
%calculating Hloss every 100M
for HLC=(1:100:500);
r0=HLC
HlossN=((Fn.*HLC.*Q.^2)./(12.*D.^5))
TEL=(Hpump-HlossN+Zs)
r1 = TEL(:,1)
HGL=(TEL-((V.^2)./2.*g))
r2 = HGL(:,1)
plot(r0,r1,'LineStyle', '--')
hold on
plot(r0,r2,'LineStyle', '--')
end

请先登录，再回答此问题。

回答（1 个）

Cris LaPierre
Cris LaPierre 2018-12-8
编辑：Cris LaPierre 2018-12-8
You plot command is inside a for-loop that runs 5 times (HLC == 1, 101, 201, 301, 401). Placing it here means it will plot the data one point at a time (not connecting them). Nothing is appearing becaues you have only specified LineStyle and no Marker style. Since no line appears when you plot a single point, the result is you see nothing in the plot. Try changing your plot command to this:
plot(r0,r1,'o','LineStyle', '--')
If you want the plot command to automatically connect the lines, first build a vector with all the numbers and then plot (outside the for loop).
  2 个评论
omar mahallawy
omar mahallawy 2018-12-9
unfortunatly i already tried the new plot with the linestyle and it only shows me the dots (unconnected)
clear,clc,clf
format long
Q=0.03;
rouh=847;
g=9.81;
Gamma=(rouh.*g);
Zs=0;
Ze=0;
L=500;
Ks=(6*10.^-5);
viscosity=(1.1*10.^-6);
V=1.34:0.5:4.5
for I=1
D=sqrt(((4.*Q))./(V.*pi))
end
Re=(V.*D./viscosity);
Er=(1.*10.^-8);
Fo=0.01;
for I=0:1:10^6;
Fn=(1./(-4.*log10((Ks./(3.71.*D))+((1.26)./(Re.*sqrt(Fo)))))).^2;
E=abs((Fn-Fo)/Fn);
if E<=Er;
display(Fn),display(E),break,
end
if E>Er;
Fo=Fn;
end
end
Hloss=((Fn.*L.*Q.^2)./(12.*D.^5))
Hpump=Hloss
%calculating Hloss every 100M
Hloss=((Fn.*L.*Q.^2)./(12.*D.^5))
Hpump=Hloss
%calculating Hloss every 100M
for HLC=(1:100:500);
HlossN=((Fn.*HLC.*Q.^2)./(12.*D.^5))
TEL=(Hpump-HlossN+Zs)
TEL1 = TEL(:,1);
TEL2 = TEL(:,2);
TEL3 = TEL(:,3);
TEL4 = TEL(:,4);
TEL5 = TEL(:,5);
TEL6 = TEL(:,6);
TEL7 = TEL(:,7);
HGL=(TEL-((V.^2)./2.*g))
HGL1 = HGL(:,1);
HGL2 = HGL(:,2);
HGL3 = HGL(:,3);
HGL4 = HGL(:,4);
HGL5 = HGL(:,5);
HGL6 = HGL(:,6);
HGL7 = HGL(:,7);
subplot(3,3,1)
plot(HLC,TEL1,'+b','LineStyle', '--')
hold on
plot(HLC,HGL1,'+b','LineStyle', '--')
subplot(3,3,2)
plot(HLC,TEL2,'+c','LineStyle', '--')
hold on
plot(HLC,HGL2,'+c','LineStyle', '--')
subplot(3,3,3)
plot(HLC,TEL3,'+m','LineStyle', '--')
hold on
plot(HLC,HGL3,'+m','LineStyle', '--')
subplot(3,3,4)
plot(HLC,TEL4,'+c','LineStyle', '--')
hold on
plot(HLC,HGL4,'+c','LineStyle', '--')
subplot(3,3,5)
plot(HLC,TEL5,'+k','LineStyle', '--')
hold on
plot(HLC,HGL5,'+k','LineStyle', '--')
subplot(3,3,6)
plot(HLC,TEL6,'+g','LineStyle', '--')
hold on
plot(HLC,HGL6,'+g','LineStyle', '--')
subplot(3,3,7)
plot(HLC,TEL7,'+r','LineStyle', '--')
hold on
plot(HLC,HGL7,'+r','LineStyle', '--')
end
Jan
Jan 2018-12-9
编辑：Cris LaPierre 2018-12-11
@omar: Cris has answered the question already and explained, that you have to create the vectors at first. See this example:
subplot(1, 2, 1, 'NextPlot', 'add');
for k = 1:10
plot(k, rand, 'o-');
end
subplot(1, 2, 2, 'NextPlot', 'add');
v = nan(1, 10);
for k = 1:10
v(k) = rand;
end
plot(1:10, v, 'o-');

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Data Distribution Plots 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by