How to extract values from a field of a stucture?

Hi everyone, I state that I'm a beginner in the use of Matlab, so I guess that what I'm asking could be solved quite easily, but I have been reading and trying a lot of different ways and still, I have no solutions. I have a structure ("Dati"), which is generated by an external software that works on a geographic grid. This grid has 196 cells in the X direction, and 337 in the Y direction; On this grid 244 different scenarios have been launched.

By writing "A=extractfield(Dati,'Val') I get, of course, the list of all the data inside the structure, and by "plot(extractfield(Dati,'X'),extractfield(Dati,'Y'))" I can represent the grid; but what I would like is to get the chance to represent in a plot the grid with all the different scenarios (244), and be able to handle the value of the third variable (energy per transport) in order to later calculate an average. Can someone help me?

Answer 1

[Fabio Freschi]

I don't have the data so I cannot test it. Try

% select the Scenario
iScenario = 1;

% plot
surf(Dati.X,Dati.Y,Dati.Val(iScenario,:,:));

Note that the field Val has different dimensions from X and Y, so the previous code doesn't work. But maybe you have more insight on the original data

[Kelto7]

Thanks for the answer, but actually it gives back an error about surf, saying that the third argument Z (that is, "Dati.Val(Scenario,:,:)" ) must be a matrix, not a scalar or vector. I understand that it expects a value for each point of the grid, which is inside Dati.Val somewhere, but since it's too big, I can't just open it.

[Fabio Freschi]

save Dati in a mat file and attach it

In any case, as i told you, the dimensions of Dati.Val do not fit X and Y

[Kelto7]

Sure, I attach the mat file; since the original had 244 cases and it was too big, I attach one with just 6 cases. Here the stucture is called "data", so in this case it's data.X, data.Y, data.Val, etc. Yes, dimensions differ one from each other.

[Fabio Freschi]

I arbitrarily remove the first row and column of X and Y to match the dimensions of Val. Maybe you know why X and Y have an additional row/col

figure;
s = surf(data.X(2:end,2:end),data.Y(2:end,2:end),squeeze(data.Val(1,:,:)));
s.EdgeColor = 'none';
light

[Kelto7]

Dear Fabio, Thank you very much for your help. Actually I must check the problem of the additional row/colum, because the plot has no sense, but it's what I was looking for! Do you think that could be possible to then organize X, Y and Z in three columns and 65520 rows (195x336), like

X Y Z

1 449604 5841736 1393.9

2 449639.531 5841771 1344.9

... .............. .............. ..............

65520 ............ .............. ..............