How to produce a graph with 2 sets of data on matlab?

Hi everyone, so i've created a code that solves an iteration for me that gives me the correct Temperature for a composition.

This leads to me needing to code for a graph Bubble Point Temperature v Composition and Dew Point Temperature v Composition.

Both in 1 graph so that I have 2 curves in the same graph.

How would I go about doing this?

Also is there a way for the graph to be produced automatically right after the code i have already coded of for provides me with the temperature?

If this doesn't make sense i'm more than happy to re-explain, i'm currently pretty sleep deprived haha.

Any help is appreciated!

Answer 1

[Star Strider]

There are several ways. The easiest way is to use the hold function.

Example:

figure(1)
plot(x1, y1)
hold on
plot(x2, y2)
hold off
grid

[Alai Yosief]

Thanks matey, i forgot to elaborate, for both set of data i'll have:

Composition of 0, 0.1, 0.2... etc. 1 and each will have a different temperature.

In that case what would my x1 and y1 be? since they'll be curves and not linear

[Star Strider]

My pleasure.

In my Answer, ‘x1’, ‘y1’ and the others represent vectors of your independent and dependent variables respectively. In each plot call, both vectors have to have the same number of elements.

[Alai Yosief]

Hey， I've been reading up on graphs and have a rough idea however I'm still getting caught up on the vector part. So here is the data I'm trying to plot: x - 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 against, Temperature - 35, 34, 34, 34, 33, 32.9, 32.8. 32.5, 32.7, 31, 30

[Star Strider]

Try this:

x = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1]; 
Temperature = [35, 34, 34, 34, 33, 32.9, 32.8, 32.5, 32.7, 31, 30];

figure(1)
plot(x, Temperature)
grid
xlabel('x')
ylabel('Temperature °C')

[Alai Yosief]

Fantastic! that worked perfectly. So I;m trying to plot 2 sets of data and I've written the following so far however it is only plotting for 1 curve instead of the both: x = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1];

Temperature = [272.78, 262.92, 259.74, 258.66, 258.30, 258.19, 258.18, 258.27, 258.68, 260.31, 266.70];

Temperature1 = [272.8, 270.4, 267.9, 265.2, 262.3, 259.3, 258.3, 258.5, 260.6, 262.7, 264.8 ,266.7];

figure(1)

plot(x, Temperature)

hold on

plot(x,Temperature1)

hold off

grid

xlabel('x')

ylabel('Temperature K')

Any Suggestions?

Thanks!!!!

[Thorsten]

You have 12 elements in Temperature1, but only 11 in x and Temperature. Get rid of one element in Temperature1 and you are done.

[Star Strider]

You have to have the same number of elements in x and Temperature in the first plot, and x and Temperature1 in the second.

One way to do that is to create x1 and x2:

x1 = linspace(0, 1, length(Temperature));
x2 = linspace(0, 1, length(Temperature1));

figure(1)
plot(x1, Temperature)
hold on
plot(x2, Temperature1)
hold off
grid
legend('Temperature', 'Temperature1')
xlabel('x')
ylabel('Temperature (°C)')

Answer 2

[Thorsten]

I deleted the final element of Temperature1, such that x, Temperature, and Temperature1 have the same number of elements:

 x = [0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1];
 Temperature = [272.78, 262.92, 259.74, 258.66, 258.30, 258.19, 258.18, 258.27, 258.68, 260.31, 266.70];
 Temperature1 = [272.8, 270.4, 267.9, 265.2, 262.3, 259.3, 258.3, 258.5, 260.6, 262.7, 264.8];

To plot, use:

 plot(x, Temperature)
 hold on
 plot(x, Temperature1)

or

 plot(x, Temperature, x, Temperature1)

or

 plot(x, [Temperature; Temperature1]')