InterX not accurate for one intersection point

I have tried to find the intersection between two lines, but it appears InterX (link below) does not return a particularly accurate value for the first intersection point. Is this the way the function works, or is it a problem with the way I am using it? Is there anyway to improve the accuracy? The code to plot the data is below and the data file is attached. The x co-ordinates are the same for both curves.

InterX: https://uk.mathworks.com/matlabcentral/fileexchange/22441-curve-intersections

clear all
close all
clc

load rawdata.mat
points = InterX([vor_x_pdf;y_poi],[vor_x_pdf;vor_y_pdf]);
loglog(vor_x_pdf,vor_y_pdf);
hold on
loglog(vor_x_pdf,y_poi);
ylim([0.001 1]);

EDIT: I've removed the file since a solution has been given.

Answer 1

[jonas]

It's because you're comparing the points one loglog scale. I suspect InterX uses linear interpolation to find the point of intersection. Try drawing a straight line on the linear scale between two points and then look at the same line on a loglog scale. It will be curved (with some exceptions)!

[Pa342]

Thanks. I have managed to find the intersection point by linearly interpolating, using "interp1", between the points on the curve. Essentially this adds more points to the curves which helps InterX find the approximate location of the intersection to a higher accuracy.

[jonas]

Yep, that would solve the issue!