필터 지우기
필터 지우기

Change the sign of a Vector over N intervals

조회 수: 3 (최근 30일)
Pierre Berthon
Pierre Berthon 2021년 3월 31일
편집: darova 2021년 4월 1일
Hi everyone,
I'm new to Matlab, my question may be super easy….I want to get a vector (Ytot ) witch is composed of the same function but with different signs set on différents intervals , that's not a problem for 2 or 3 vectors , but i dont know how to manage it with n intervals ?
This is an example :
Y = function_example;%%%% (define on 1 : 100)
T = [1; 9 ;17 ;...….89; 100] ;%%%(for example 24values)
A = [-1; 1 ; 1; ......…..-1]; %%% signs for each intervals
Y1 = -1*Y(1:9); %%% equal to Y between 1 and 9, and equal to 0 between 10 and 100
Y2 =1*Y(9:17);
Y24 =-1*Y(89:100);
t1 = (1: 1: 9);
t2 = (9: 1: 17);
tn = (89 :1: 100);
Ttot = [t1 +t2+...t24];
Ytot = [Y1 + Y2 + .Y24];

답변 (1개)

Rafael Hernandez-Walls
Rafael Hernandez-Walls 2021년 3월 31일
Use something like this:
Y=rand(1,20);
d=[1:4,8:12,17:20];
Y(d)=-Y(d)
  댓글 수: 1
Pierre Berthon
Pierre Berthon 2021년 4월 1일
I must have say that Y is a vector define previously by a function... Furthermore, how do you define d for N intervals ? Lets explain with another example :
X =[0: 0.1 :3*pi()];
Y = abs(sin(X));
A = [1;-1;1]; % intervals were I want to change sign of vector Y, equal to the number of peaks
%% I use findpeaks to find were the peaks begin and end with locals minimum, it returnes me B
B = [0; pi(); 2*pi(); 3*pi() ]; %begins and end of each peaks % with this function sin its easy because every intervals have the same length and there ara only 3 peaks, but at the end i want to do it with a much more complicated Vector Y with intervals of different lenghts and multiple peaks ( values 1 or -1 are enter by the user of the program )
Then i wanna have sin(x) between 0 and pi , -sin(x) between pi and 2*pi, sin between 2*pi and 3*pi ect...
So thats why i thought about doing a concatanation with N intervals of N vectors Y , each Y (Y1,Y2 ect...) define oneach intervals ( B(0 : pi), B( pi : 2*pi) ect...) but its maybe not the best way to do it ...

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 Creating and Concatenating Matrices에 대해 자세히 알아보기

제품


릴리스

R2018b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by