How do I plot a function with multiple steps

10 views (last 30 days)
Hello,
I am trying to plot a function, Re. This function requires a size, which I have called y. How can I plot Re, with the size of y changing. It gives me a straight line. Thanks for the help, I am very new to this.
syms y z a b c
x=10
viscosity=(1.8*10^-5)
Pi=3.1415926
Densityair=1.25
Densitypart=1000
for y=(.01*10^-9):(1*10^-2)
yint=(.01*10^-9)
y=yint+(1*10^-6)
Re=(Densityair*x*y)/viscosity
fplot(Re)
end

Accepted Answer

VBBV
VBBV on 23 Sep 2021
syms y z a b c
x=10
viscosity=(1.8*10^-5)
Pi=3.1415926
Densityair=1.25
Densitypart=1000
y=(.01*10^-9):(0.01*10^-9+10^-6):(1*10^-2);
Re=(Densityair*x*y)/viscosity
plot(Re)
You can use simple plot function
  2 Comments
Alexander Garber
Alexander Garber on 23 Sep 2021
That part works, thanks. Next, I need to use that function to define another function. It is now saying that the matrix definitions must agree. How should I fix this
syms y z a b c
x=10
viscosity=(1.8*10^-5)
Pi=3.1415926
Densityair=1.25
Densitypart=1000
y=(.01*10^-9):(0.01*10^-9+10^-6):(1*10^-2);
Re=(Densityair*x*y)/viscosity
Cd=piecewise(Re<.1, (24/Re), .1<Re<2, (24/Re)*(1+.1875*Re+.05625*Re*Re*ln(2*Re)), 2<Re<500, (24/Re)*(1+.15*Re^.687), Re>500, .44)
plot(Cd)
VBBV
VBBV on 23 Sep 2021
syms y z a b c
x=10
viscosity=(1.8*10^-5)
Pi=3.1415926
Densityair=1.25
Densitypart=1000
y=(.01*10^-9):(0.01*10^-9+10^-6):(1*10^-2);
Ree=(Densityair*x*y)/viscosity;
plot(Ree)
syms Re
Cd=piecewise(Re<.1,(24./Re),0.1<Re<2, (24./Re).*(1+0.1875*Re+0.05625*Re.*Re.*log(2*Re)), 2<Re<500, (24./Re).*(1+.15*Re.^0.687), Re>500, 0.44)
CdY = double(subs(Cd,Re,Ree));
You can use element wise operators in your expression

Sign in to comment.

More Answers (0)

Categories

Find more on Function Creation in Help Center and File Exchange

Tags

Products


Release

R2021a

Community Treasure Hunt

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

Start Hunting!