MATLAB查找数组元素并有条件地添加到常量

Question

Given this array of angles:

  123.5280
  129.5280
  129.0130
  136.2960
  139.1640
  145.7430
  148.9800
  156.9080
  168.3440
  179.2340
    3.0840
    3.9720

I would like to identify those which are < 90 degrees

angles(angles < 90)

ans =

    3.0840
    3.9720

and add 180 to only those two having as a result

  123.5280
  129.5280
  129.0130
  136.2960
  139.1640
  145.7430
  148.9800
  156.9080
  168.3440
  179.2340
  183.0840
  183.9720

How do I achieve this?

Answer 1

angles(angles < 90) = angles(angles < 90) + 180

Answer 2

The behaviour you are looking for is called (phase) unwrapping and there's a built in function unwrap for that

res = unwrap(angles / 90 * pi) / pi * 90

Note that unwrap works in radians and for jumps of +/-pi and not 2*pi as you request, hence I'm intentionally scaling with 90 * pi instead of 180 * pi . Also see the discussion here .

Answer 3

一行解决方案：

angles=angles+(angles<90)*180;