Scatter not showing full precision of data.

I am trying to plot one measurement versus another withing the scatter function as such below but the result is that data is "sampled" at a much lower precision that the two column vectors I am supply it with. I have made sure to specify format long in my script. Any help would be beyond appreciated. I have attached the data below. It has ~16 digits of precision but I am not getting the double precision it says it is (as seen in the graph below).

figure;
hold on 
scatter(ztemp,zrate,".")
ylabel('Angular Rate \omega_z [deg/s]');
xlabel('Rate Sensor Temperature Measurement [deg C]');
title('Angular Rate Measurements Vs. Temperature Sampled and Fitted');
ylim([-0.6 0.6])
xlim([-15 60])
hold off
saveas(gcf,'Angular Rate Measurements Vs. Temperature Sampled and Fitted.png')

[Walter Roberson]

if you calculate

duz = diff(unique(zdiff)) ;
min(duz)

what shows up?

[Dyuman Joshi]

format only changes the way how the numerical values are displayed. It has no effect how numbers are stored and used for operations.

I don't understand what exactly your question is.

Answer 1

[Walter Roberson]

format long g
whos -file data.mat

  Name             Size              Bytes  Class     Attributes

  zrate      1180160x1             9441280  double              
  ztemp      1180160x1             9441280  double              

load('data.mat');
duz = diff(unique(zrate)) ;
min(duz)

ans = 
        0.0183199942111969

min(zrate), max(zrate)

ans = 
        -0.146559998393059

ans = 
         0.494639992713928

You may have 16 bits of precision, but your zrate is in bands that at least 0.018 apart.

G = findgroups(zrate);
max(G)

ans = 
    36

You only have 36 different zrate values.

scatter(ztemp,zrate,".")

If you were to increase your ylim enough then the difference of 0.0183 between layers would be insignificant compared to the span, and in that case it would look continuous... but it would not be.

figure();
scatter(ztemp,zrate,".")
ylim([-1 1])

Answer 2

[Chunru]

websave("data.mat", "https://www.mathworks.com/matlabcentral/answers/uploaded_files/1514124/data.mat")

ans = '/users/mss.system.yOZ4c1/data.mat'

load("data.mat")
figure;
hold on 
scatter(ztemp,zrate,".")
ylabel('Angular Rate \omega_z [deg/s]');
xlabel('Rate Sensor Temperature Measurement [deg C]');
title('Angular Rate Measurements Vs. Temperature Sampled and Fitted');
ylim([-0.6 0.6])
xlim([-15 60])

% whos
figure
% Your data (zrate) is in discrete groups
histogram(zrate)

figure
plot(sort(zrate))