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Hi, I am trying to generate a speed range in MATLAB. Let V is the speed, then how to write the coding to find the speed range of:

0<V<=12

12<V<=20

20<V<=30

30<V<=40

40<V<=50

50<V<=60

60<V<=70

70<V<=80

80<V<=90

90<V<=100

100<V<=110

V>110

Walter Roberson
on 9 Apr 2018

or you can use the second output of histc() or the third output of histcounts()

njj1
on 18 Apr 2018

KSSV
on 9 Apr 2018

V = 1:100 ;

idx = V>=10 & V<=20 ; % Get indices of velocities lying between 10 to 20

V(idx)

rahim njie
on 22 Jul 2021

thank.

Also i have written code that solves 3D kinematics problem. the code calculates angular velocity at set precsion angle of 60. what function do i use that will allow me to use the same code but calculate the velocity and angle from 1-60 degrees.

i have vectors in some of the calucations so using 'theta= 1:60' Caused erros

thanks

Walter Roberson
on 22 Jul 2021

Edited: Walter Roberson
on 22 Jul 2021

theta = (0:60).';

and remember to use cosd() and sind()

Notice the .' there: it is transposing the 0:60 from a row vector into a column vector. When you combine this with row vectors, then the result would be to implicitly expand to two dimensions. For example,

v = 1:100;

theta = (0:60).';

dist = (v - v.^2/100) .* sind(theta);

surf(v, theta, dist, 'edgecolor', 'none')

size(v), size(theta), size(dist)

Walter Roberson
on 27 Jul 2021

theta= (1:60).'; % precession angle

w_s = 10; % angular velocity of spin

a_s = 6; % angualar acceleration of spin

w_n = 3; % angular velocity of nutation

a_n = 2; % augalar acceleration of nutation

w_p = 5; % angular velocity of precession

a_p = 4; % angular acceleration of precession

%% Geometry values

rA = [0 7.4103 7.1651];

%% vectors

Z = zeros(size(theta));

vw_s = [Z, w_s*sind(theta), w_s*cosd(theta)]; % spin vector

vw_p = [0 0 w_p]; % precession vector

vw_n = [-w_n 0 0]; % nutation vector

%% Angualar velocity

wi = [-w_n 0 0]; % i component of W

wj = [Z w_s*sind(theta) Z]; % j component W

wk = [ Z Z (w_p + w_s*cosd(theta))]; % k component of W

W = wi + wj + wk; % Angular Velocity;

size(W)

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