How to change the y-axis values to start at 0 and not become negative?

How can i make it so that my plot starts at 0 and doesn't go below 0 into the negative numbers, also I'd like to use a range from 0 to 1.7 on my y-axis but am unable to. Thank you!

clc;
close all; 
clear all;

% Importing video from files
vid = VideoReader('portfolio3/Tennis1.mp4');

% Converting the video into frames
frames = read(vid);

% Finding the size and length of the video
si = size(frames)

% % Creating a vector to store positions of the vector
posVec = [];

%% Cropping and greying the video for facile processing

% for all frames
for i = 1 : si(4)
    % Cropping frame by frame
    CroppedFrame = imcrop(frames(:,:,:,i),[120 90 450 1000]);
    
    % Coverting to grey 
    CroppedFrame = rgb2gray(CroppedFrame);
    
    % Binarising
    CroppedFrame = im2bw(CroppedFrame,0.7);
    
    % Removing flexes
    CroppedFrame = imopen(CroppedFrame,strel('disk',3));
    
    imshow(CroppedFrame);
    
    % Tracking the ball in the video
    
    [pos,rad] = imfindcircles(CroppedFrame,[13 100]);
    viscircles(pos,rad);

    drawnow
    
    % Adding the current position to the position vector
    posVec = [posVec; pos];
end

scatter(65-posVec(:,1),365-posVec(:,2));
pbaspect([1000 1000 1000])


hold on;
title('Bouncing Ball Trajectory')
xlabel('Horizontal Displacement')
ylabel('Vertical Displacement')

This is what I am getting so far

Answer 1

[Jan]

It is not clear, what you are asking for.

You can limit the Y axis by:

ylim([0, 1.7])

This would crop almost all points from the diagram.

Maybe you want to scale the data instead. Where do the constants in this expression come from:

scatter(65-posVec(:,1),365-posVec(:,2));
%       ^^             ^^^  ?

What about:

posVec = -posVec;
posVec = posVec - min(posVec);        % Starting at 0
posVec = 1.7 * posVec / max(posVec);  % maximum value scaled to 1.7

[Muhammad Choudhury]

Apologies the constants were not changed from a previous video i processed, essentially what I wanted to do was begin at at 1.7 on my y-axis and begin end at 1 on my x-axis but couldn't get it to work. This is what I tried using next:

scatter(1-posVec(:,1),1.7-posVec(:,2));

For the last code you provided I am getting an error saying:

"Index in position 2 exceeds array bounds (must not exceed 1).

Error in Tennis (line 50)

scatter(1-posVec(:,1),1.7-posVec(:,2));"

I'm not quite sure what to do here.