I would like to plot few values of a vector based on threshold setting from another vector.

clear all;

close all;

x=[1 2 3 4 5 6 7 8 9 10];
y=[1 2 3 4 5 6 7 8 9 10];
figure () 
plot(x(y>3 & y<5),y(y>3 & y<5))

if i will write plot(x(y>3 ),y(y>3)) it works, but I can not make it work for two different thresholds

Answer 1

[dpb]

It works; you just can't see the single point that is left because the single point on a default line width without a marker just is too small/light to be able to see...

x=[1 2 3 4 5 6 7 8 9 10];
y=[1 2 3 4 5 6 7 8 9 10];
subplot(2,1,1)
plot(x(y>3 & y<5),y(y>3 & y<5),'kx-')
xlim([0 10])
subplot(2,1,2)
plot(x,y,'kx-')
hold on
lo=3; hi=8;         % set different range; use variables instead of burying magic numbers in code..
plot(x(y>lo & y<hi),y(y>lo & y<hi),'r-')     % now will show up with default line width
xlim([0 10])

ADDENDUM

Here is place I like my "syntactical sugar" routine iswithin to reduce clutter in the user code by moving the comparisons to a lower level -- using it the above could be written as

lo=4;hi=4;                                  % duplicate original, iswithin is inclusive 
ix=iswithin(x,lo,hi)&iswithin(y,lo,hi);     % logical addressing vector
plot(x(ix),y(ix),'kx')                      % plot original with a marker

where iswithin is

function flg=iswithin(x,lo,hi)
% returns T for values within range of input
% SYNTAX:
%  [log] = iswithin(x,lo,hi)
%      returns T for x between lo and hi values, inclusive

  flg= (x>=lo) & (x<=hi);
end

I keep a "Utilities" subdirectory as part of my MATLABPATH just behind my current working directory in order; such general-use functions such as this reside there so are always available.

[Panagiotis Bonas]

You are right, Thank you a lot for your answer :)

[dpb]

So, if it solves the problem, ACCEPT it so others can know if nothing else.

Answer 2

[Kevin Holly]

x=[1 2 3 4 5 6 7 8 9 10];
y=[1 2 3 4 5 6 7 8 9 10];
x(y>3 & y<5)

ans = 4

y(y>3 & y<5)

ans = 4

figure
plot(x(y>3 & y<5),y(y>3 & y<5),'r')

figure
scatter(x(y>3 & y<5),y(y>3 & y<5),'r')

[Panagiotis Bonas]

Thank you for the answer :)