"for" cycle to plot the point in a matrix with a certain radius

Hi everyone,

I have a compressor blade defined in polar-cylindrical coordinates and I would like to write a script that plot just the points located at a certain radius (that will correspond to the hub or to the shroud of the blade).

I tried to use the code below, but it did not work.

Does anyone could help me?

Thank you very much

clear all
close all
clc

data = importdata("blade_pol.mat")
radius = data(:,1)
x = data(:,3);
y = data(:,1).*data(:,2);
for k = 1:size(data,1)
    if radius(k,1) == 0.1160
    plot(x(k),y(k))
    end
end

Answer 1

[Dyuman Joshi]

You should use tolerance to compare floating point numbers. Set tolerance according to the level of precision you want.

And use hold on command to retain all the points on the same plot, otherwise your plot will be over-written.

for k = 1:size(data,1)
    if abs(radius(k,1) - 0.1160)<1e-4 %tolerance
    plot(x(k),y(k))
    hold on
    end
end

[javarocket]

Thank you very much!!