Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

Thread Subject:
Fixing Data Plots (Vector length problems)

Subject: Fixing Data Plots (Vector length problems)

From: Mary

Date: 30 Apr, 2013 00:13:12

Message: 1 of 2

Hello!

I am plotting vectors that are equal to the change in angle of a persons arm from motion capture data!

My main problems arise from the start and stop times of the data collected. (For example one person starts at 2 seconds, the next trial starts at 2.5 seconds, but the general lengths from start to end of a motion are the same)

The image posted below is an example of 2 of these trials plotted on top of one another.
What I would like to do is allign them so that the starting point (where the rate of change begins to increase) so that I can more meaningfully compare them visually.

(image link: http://i.imgur.com/8purobD.png )

Any help would be appreciated!

Many Many Many Thanks,

Mary

Subject: Fixing Data Plots (Vector length problems)

From: dpb

Date: 30 Apr, 2013 00:46:31

Message: 2 of 2

On 4/29/2013 7:13 PM, Mary wrote:
> Hello!
>
> I am plotting vectors that are equal to the change in angle of a persons
> arm from motion capture data!
>
> My main problems arise from the start and stop times of the data
> collected. (For example one person starts at 2 seconds, the next trial
> starts at 2.5 seconds, but the general lengths from start to end of a
> motion are the same)
>
> The image posted below is an example of 2 of these trials plotted on top
> of one another. What I would like to do is allign them so that the
> starting point (where the rate of change begins to increase) so that I
> can more meaningfully compare them visually.
> (image link: http://i.imgur.com/8purobD.png )
>

Same as before...you have to define what it is that "align" really means.

As before, if all you care about is the beginning over laying simply
find the point however it was you ended up doing so earlier (iirc there
was a post that said you had done so but not how you chose in the end to
do so) and then just begin each plot at that point to end. Simplest
would be then to fill to common length w/ NaN so can keep a fixed array
size.

Essentially, just apply post-acquisition triggering on the waveforms and
shift them to an equivalent pretrigger delay.

--

Tags for this Thread

What are tags?

A tag is like a keyword or category label associated with each thread. Tags make it easier for you to find threads of interest.

Anyone can tag a thread. Tags are public and visible to everyone.

Contact us