How creat graphics from differents matrices using a loop?

These are the matrices. There's more, but I just copied enough to give the ideia

M7 = importdata('D:\documentos\20V\Ag20V15A-60min.txt');

% 15 mA 20V 80 min

M8 = importdata('D:\documentos\20V\Ag20V15A-80min.txt');

% 15 mA 20V 80 min Aberto %

M9 = importdata('D:\documentos\20V\Ag20V15A-80min-Aberto.txt');

% 15 mA 20V 120 min

M10 = importdata('D:\documentos\20V\Ag20V15A-1290min.txt');

% 15 mA 20V 120 min Aberto

M11 = importdata('D:\documentos\20V\Ag20V15A-120min-Aberto.txt');

x = M9(1:2:end,1);

y = M 9(1:2:end,2);

x3 = M10(1:2:end,1);

y3 = M10(1:2:end,2);

x4 = M11(1:2:end,1);

y4 = M11(1:2:end,2);

[darova]

Please attach some data so we can experiment

How the final image you expect to see should looks like? Maybe some drawing?

[Stephen23]

Numbered variables are a sign that you doing something wrong. Using numbered variables makes accessing your data complex, slow, obfuscated, buggy, and difficult to debug.

You should just use indexing instead (e.g. into aN ND numeric array, a cell array, a table, etc). Indexing is simple, neat, easy to debug, and very efficient.