Extract plot statistics for a specific range

Hi all, hope you are well.

I have a very basic question regarding the Data Statistics tool.

I'm plotting several acoustic metrics (such as sharpness, fluctuation strength etc) and am able to import data files (.wav) and plot the data without any issues. I have also made use of the Data Statistics tool to calculate the mean and max of the plotted data.

What I'm trying to do now is extract the data statistics for a specific range of the data - for example, the mean sharpness between 2 and 4 seconds of the audio file.

I'm sure there is a way to do this with some code etc - but I was hoping there would be a way to do it interactivly within the plot - almost like a set of cursors which can be moved which set the start and end points?

Any help is gratefully recieved.

All the best,

Andy

Answer 1

[Star Strider]

I don’t have the Curve Fitting Toolbox, however looking at the documentation for the datastats function, one option would be:

Lv = x >= 2 & x <= 4; % Logical Vector

[xds,yds] = datastats(x(Lv),y(Lv))

That should give you the result you want.

Example —

x = linspace(0, 20, 250).';
y = sin(2*pi*x/10) .* cos(2*pi*x/5) + randn(size(x))/5;

figure
plot(x, y)
grid

[xds,yds] = datastats(x, y)

xds = struct with fields:
       num: 250
       max: 20
       min: 0
      mean: 10
    median: 10
     range: 20
       std: 5.8083

yds = struct with fields:
       num: 250
       max: 1.2744
       min: -1.2245
      mean: 0.0014
    median: 0.0201
     range: 2.4989
       std: 0.5211

Lv = x >= 2 & x <= 4;                                                % Logical Vector
[xds24,yds24] = datastats(x(Lv),y(Lv))

xds24 = struct with fields:
       num: 25
       max: 3.9357
       min: 2.0080
      mean: 2.9719
    median: 2.9719
     range: 1.9277
       std: 0.5911

yds24 = struct with fields:
       num: 25
       max: 0.4296
       min: -1.2245
      mean: -0.5585
    median: -0.6942
     range: 1.6541
       std: 0.4971

Make appropriate variable name changes to work with your data.

.

Answer 2

[phenan08]

You can try data selection using ginput. Example below:

x = rand(100,1) ; % generation of fake data

y = rand(100,1) ; % generation of fake data

figure ;

plot(x,y,"o") ;

selection = ginput(2) ; % selection of the bounds in the plot

tf = x >= min(selection(:,1)) & x <= max(selection(:,1)) ; % test to check whether the data belong to the selected interval or not

figure ;

plot(x(tf),y(tf),"o") ; % plotting the selected data

Then you can make data statistics on the selected data x(tf) and y(tf).