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Plot blocks of points with a specific color

Asked by Tiago Dias on 26 Nov 2018
Latest activity Answered by Tiago Dias on 28 Nov 2018
Hi,
I got these points and I want to colour every 4 points with a specific color:
x = [ 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5]';
y = [ 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5]';
Point 1:4 yellow, 5:8 blue, 9:12 red, etc, and I want to plot all the 25 entries. the last "block" with just have the row number 25.
I though doing this:
[n,~] = size(x);
block_points = 4;
t_start = 1:block_points:n;
t_end = block_points:block_points:n;
but I got a problem with t_end, only has size 6, while t_start has size 7, due to the last block that only has 1 number.
Thanks for your help

  4 Comments

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I just want to delete que question, solved the problem on my own
ok so the effort put in order to help is for nothing? Just leave it open just don‘t accept the answer. Post your solution as an answer and accept it.
First of all, I did not say that your help was for nothing, I appreatiate the time you spend on my question, like I wrote in the last comment I wrote.
I think I should not accept your answer since, it was not what I looking for, I wanted a more automatic procedure, depending on the variables and not the numbers. I was looking for something that could always work, no matter the X and Y provided, and I was able to acomplish that.
Like I said, thanks for your interest in my question, and the effort that you spent on it.

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2 Answers

Answer by Tiago Dias on 28 Nov 2018
 Accepted Answer

This is what I did to solve my question:
from a generic
X = [1:25]';
Y = [1:25]';
I want to plot each number of "rows" to a specific color
[n,m] = size(X);
rows = 3;
columns = ceil(n/rows);
extra_row = columns * rows;
X(n+1:extra_row) = NaN; Y(n+1:extra_row) = NaN;
X_new = reshape(X,rows,columns); Y_new = reshape(Y,rows,columns);
legenda = sprintfc('Mes %d', 1:columns);
for j = 1:size(X_new,2)
plot(X_new(:,j),Y_new(:,j),'*')
hold on
end

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Answer by madhan ravi
on 26 Nov 2018
Edited by madhan ravi
on 26 Nov 2018

EDITED
xx = [ 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5]';
yy = [ 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5]';
x=reshape(xx(1:end-1),4,[]);
y=reshape(yy(1:end-1),4,[]);
s={'-oy','-ob','-or','-og','-om','-oy'};
for i=1:size(x,1)
plot(x(i,:),y(i,:),s{i})
hold on
end
plot(xx(end),yy(end),'ok',...
'markerFaceColor','k')

  9 Comments

I understood that, but if my X has 26 elements, i need to handly plot the last 2. if it has 27 i need to handly plot the last 3.
I would prefer, if it is doable, an aprroach that would read the size of X and reshape in function of the number 4, or 3 or 5 or whatever I need.
I would like to do a reshape of x, transform a X of 1xm into a 4xceil(n/4), where n is the number of rows of X.
I would transform a 26x1 matrix into a 4x7 matrix, with the 2 last entries could be NaN values for example.
x(1) x(5) x(9) x(13) x(17) x(21) x(25)
x(2) x(6) x(10) x(14) x(18) x(22) NaN
x(3) x(7) x(11) x(15) x(19) x(23) NaN
x(4) x(8) x(12) x(16) x(20) x(24) NaN
i want the reshape to do this, or someother tool to get this, when i say i need 4 rows and 7 columns, that i can calculate there 2 parameters based on my original x
"I would transform a 26x1 matrix into a 4x7 matrix, with the 2 last entries could be NaN values for example."
matrix=[rand(26,1);zeros(2,1)] %this will do what you want just pad the remaining elements with zeros
I am not explaining my self properly, i want it to be automaticly, i created a new topic for this, thanks for your time !

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