How do i know to which graph i'm plotting?

 data1 = load('data1.mat')
 data2 = load('data2.mat')

by doing `plot(val(1, :))` i have a graph but I don't know if it corresponds to data 1 or data 2 how can I choose the data in plots?

the second question is how can I concatenate data1 and data 2 basically let's say data1 is 1 2 3 and data2 is 4 5 6 the expected outcome would be :

    1 2 3
    4 5 6

then plot them both in the same figure?

Answer 1

[Nesha Wright]

To concatenate then use the command 'cat', to plot both 'plot(catdata)' or use the command 'hold on' if you decide not to concatenate them but still want to plot both.

[Elias Unk]

I want to draw the content of data1 and data2 on the same figure

Answer 2

[Walter Roberson]

I think you missed a line of code connecting data1 and data2 to val ?

For your other part:

combined = [data1; data2];
plot(combined.')

When you ask to plot a 2D array, plot() prefers to plot by column. Your combined would have three columns, so if you had done

plot(combined)

you would get three lines.

I say "prefers" to plot by columns because when you pass an x, y pair,

plot(x, combined)

then if x is a vector then x and y will be automatically transposed if needed so that size(x,1) = size(y,1). For example, plot(1:3, combined) would notice that x was length 3 and would automatically transpose combined to match.

[Elias Unk]

Plotting combined gave this error >> plot(combined.') Error using plot Not enough input arguments. and i can simply do this:

plot(data.val(1,:));hold on; plot(data2.val(1,:))
but what if i have 15 graphs i just want a methods that draws all the graphs in a matrix

[Walter Roberson]

What shows up for

class(combined)
size(combined)
which plot(combined)

[Elias Unk]

In order:

struct

2 1

built-in (C:\Program Files\MATLAB\MATLAB Production Server\R2015a\toolbox\matlab\graph2d\plot)

[Walter Roberson]

Try

combined = [data1.data1; data2.data2];

Answer 3

[Image Analyst]

If you assigned data1 to val, then plotting val would plot data1. If you assigned data2 to val, then plotting val would plot data2.

To plot both data1 and data2 on the same axes:

plot(data1, 'b*-', 'LineWidth', 2, 'MarkerSize', 10);
grid on;
hold on;
plot(data2, 'rs-', 'LineWidth', 2, 'MarkerSize', 10);
xlabel('Index', 'FontSize', 20);
ylabel('Value'FontSize', 20);