Trying to plot two column vectors
I haven't used MATLAB in a while so i can't figure out what I'm doing wrong here.
I want to plot (on one graph) curve开发者_开发知识库s for 4 different Temperatures. V
should be on the x-axis and P
should be on the y-axis.
What I have after the %
is just a reminder for me and has nothing to do with what I'm doing in the plot.
Here's what I have in my editor:
a=3.7E-7;
b=4.3E-5;
R=8.314E-6;
n=1;
V1_vector=zeros(1,25);
P1_vector=zeros(1,25);
T1=400;
V1=.0000823;
for n=1:1:25
P1=((R*T1)/(V1-b))-(a/(V1.^2));
V1_vector(n)=V1;
P1_vector(n)=P1;
V1=V1+.001324708; %V1=0.0332
n=n+1;
end
P1=P1_vector;
V1=V1_vector;
V2_vector=zeros(1,25);
P2_vector=zeros(1,25);
T2=350;
V2=.00007133;
for n=1:1:25
P2=((R*T2)/(V2-b))-(a/(V2.^2));
V2_vector(n)=V2;
P2_vector(n)=P2;
V2=V2+.0011579468; %V2=0.02902
n=n+1;
end
P2=P2_vector;
V2=V2_vector;
V3_vector=zeros(1,25);
P3_vector=zeros(1,25);
T3=300;
V3=.00006347;
for n=1:1:25
P3=((R*T3)/(V3-b))-(a/(V3.^2));
V3_vector(n)=V3;
P3_vector(n)=P3;
V3=V3+.0009906612; %V3=0.02483
n=n+1;
end
P3=P3_vector;
V3=V3_vector;
V4_vector=zeros(1,25);
P4_vector=zeros(1,25);
T4=250;
V4=.0000577453;
for n=1:1:25
P4=((R*T4)/(V4-b))-(a/(V4.^2));
V4_vector(n)=V4;
P4_vector(n)=P4;
V4=V4+.000825690188; %V4=0.0207
n=n+1;
end
P4=P4_vector;
V4=V4_vector;
PLOT(V1,P1,V2,P2,V3,P3,V4,P4)
This is the error message
??? Attempt to execute SCRIPT Plot as a function:
C:\Users\amy\Documents\MATLAB\Plot.m
Error in ==> Plot at 73
PLOT(V1,P1,V2,P2,V3,P3,V4,P4)
Please help me!
It looks like you made a file called "Plot.m", which is what's being called instead of the matlab "plot" routine.
Rename the file "C:\Users\amy\Documents\MATLAB\Plot.m" to something else.
As pointed out by @nsanders, you have a user-defined function plot.m
shadowing the built-in function by the same name. When in doubt, you can always check:
>> which plot -all
C:\Users\amy\Documents\MATLAB\plot.m
[... a bunch of other overrided versions ...]
built-in (C:\MATLAB\R2010a\toolbox\matlab\graph2d\plot) % Shadowed
Also, MATLAB is case-sensitive, so you should call the function as plot
(small letters)
If you are wanting to plot the points (V1, P1)
, (V2, P2)
, etc, put the points in a vector before plotting them. Try plot([V1, V2, V3, V4],[P1, P2, P3, P4])
.
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