How to do this kind of contour plot?

I just want to plot a graph like this:

I know it's a contour plot, but I don't know how to do it.

I wanna plot several curves (as shown in the figure) vs another parameter, for example:

Curve 1: X-Axis --> Voltage | Y-Axis --> Current | For T = 10ºC
Curve 2: X-Axis --> Voltage | Y-Axis --> Current | For T = 20ºC
Curve 3: X-Axis --> Voltage | Y-Axis --> Current | For T = 40ºC
Curve 4: X-Axis --> Voltage | Y-Axis --> Current | For T = 60ºC
Curve 5: X-Axis --> Voltage | Y-Axis --> Current | For T = 80ºC

Somebody could help me? Thanks in advance.

[KSSV]

contour is the one you need. What problem you have?

[Juan Castillo]

Hi, thanks for your help.

Please read my last comment for more info.

Answer 1

[jonas]

Basically you don't define data along lines but rather on a full rectangular grid. Let's say you want to plot data between x=0:10 and y=0:10.

x=0:10;
y=0:10;
[X,Y]=meshgrid(x,y)

This will give you a grid (11x11). Now define the function Z(Y,X) which you want to plot. For example:

Z=X.^2+Y.^2
[C,h]=contour(X,Y,Z)

You can also define the number of contours as a fourth argument. Finally, you can label the contours by adding:

clabel(C,h)

Hope this helps

[Juan Castillo]

Thank you very much for your help.

I know what you mean, in fact I tried it before with no results. My problem here is that the Z parameter (temperature in my example) is not function of X or Y, this parameter is independent and variable in each curves, so, is there any solution?

Thanks again

[jonas]

There is always a solution, but I'm not entirely sure what it is that you want to Plot. The point of a contour Plot is that Z is constant along the contour. What do you have on XYZ? What does the curve signify?

[Juan Castillo]

Hi again, im gonna explain it a little bit more:

My intention is to plot some curves for diferent values of the temperature. Example:

Current through a resistance:

For T = 20ºC --> X-axis: Voltage from 0 to 5 V, Y-axis: Current measured. Curve 1.
For T = 40ºC --> X-axis: Voltage from 0 to 5 V, Y-axis: Current measured. Curve 2.
For T = 60ºC --> X-axis: Voltage from 0 to 5 V, Y-axis: Current measured. Curve 3.

My Z parameter here is the temperature, and it's not dependent of X or Y, its variable (by me) and I know it's value.

Do you understand me now?

Thanks again

[jonas]

Perhaps. So you have some function y(x) at different T? And you want to plot those functions?

If thats the case, then a contour plot is not what you need.

What are the dimensions of your data set?

[Juan Castillo]

Exactly. That's what I wanna plot.

For example. The dimensions are:

Curve 1. Tº = 20ºC

X-Axis: Voltage

0
0,02
0,04
0,06
0,08
0,1
0,12
0,14
0,16
0,18
0,2
0,22
0,24
0,26
0,28
0,3
0,32
0,34
0,36
0,38
0,4
0,42
0,44
0,46
0,48
0,5
0,52
0,54
0,56
0,58
0,6
0,62
0,64
0,66
0,68
0,7
0,72
0,74
0,76
0,78
0,8
0,82
0,84
0,86
0,88
0,9
0,92
0,94
0,96
0,98
1
0,98
0,96
0,94
0,92
0,9
0,88
0,86
0,84
0,82
0,8
0,78
0,76
0,74
0,72
0,7
0,68
0,66
0,64
0,62
0,6
0,58
0,56
0,54
0,52
0,5
0,48
0,46
0,44
0,42
0,4
0,38
0,36
0,34
0,32
0,3
0,28
0,26
0,24
0,22
0,2
0,18
0,16
0,14
0,12
0,1
0,08
0,06
0,04
0,02
0

Y-Axis: Current measured

1,6785E-6
6,5565E-5
1,334E-4
2,035E-4
2,7375E-4
3,496E-4
4,2841E-4
5,1111E-4
5,9634E-4
6,7216E-4
7,7429E-4
8,6436E-4
9,6434E-4
0,00108
0,00121
0,00137
0,00149
0,00171
0,00198
0,00231
0,00272
0,00309
0,00359
0,00419
0,00498
0,00557
0,00656
0,00722
0,00801
0,00863
0,00952
0,01034
0,01112
0,01174
0,01314
0,01408
0,01473
0,01561
0,01614
0,01688
0,01806
0,01863
0,0193
0,02016
0,021
0,02143
0,02205
0,02277
0,02365
0,02436
0,0251
0,02484
0,02425
0,02372
0,02336
0,0228
0,02225
0,02166
0,02109
0,02056
0,01999
0,01944
0,0189
0,01835
0,01783
0,0173
0,01676
0,01623
0,01571
0,01519
0,01466
0,01415
0,01364
0,01312
0,01261
0,0121
0,0116
0,01109
0,01059
0,01009
0,00958
0,00909
0,00859
0,0081
0,00761
0,00712
0,00663
0,00615
0,00566
0,00518
0,0047
0,00422
0,00375
0,00327
0,0028
0,00233
0,00186
0,00139
9,2199E-4
4,5571E-4
1,168E-5

Curve 2. Tº = 40ºC

X-Axis --> Same

Y-Axis --> Same with another values

And so on. All the curves have the same dimensions.

Thanks again for your patience.

[jonas]

Hi again, sorry for the late reply. Based on the comments, what you want is an ordinary plot, like this:

h=plot(x,y1,...
x,y2,...
x,y3) %and so on

You can also add labels using text. Adding a colorbar to a 2d-plot is not as trivial, but it can be done by setting the line colors based on a colormap and a temperature vector, or alternatively by using something like this non-default function 3d color line (link)

This will not give you a plot identical to the one in your figure, which I believe is a surface plot (with data on a full rectangular grid). If you want to obtain similar results, then there are some different solutions. To be honest, having both colors AND clabels (as in the figure) is however unnecessary. Anyway, let me know if you still want that.