[pulseview.git] / manual / analysis.txt

== Data Analysis

Once you have acquired some measurement data, it's time to have a look and see what
insights you can gain from it. Usually, the first step is to look at the data as a
whole, achieved by clicking the _Zoom to Fit_ button:

image::pv_analysis.png[]

<1> Zoom-to-Fit button
<2> Zoom in/zoom out buttons
<3> Cursors
<4> Time scale (used to set up and show time markers, see below)

If you have located an area of interest (maybe with the help of decoders, more about
that later), you can zoom in on it using the _zoom in_/_zoom out_ buttons, using the
scroll wheel of your mouse or the pinch/expand gestures on your touch panel.

[NOTE]
When a data capture is ongoing, the Zoom-to-Fit button stays active if you click it,
meaning that PulseView automatically fits all data to the views until either the
capture is finished or the Zoom-to-Fit button is clicked again.

=== Cursors and Time Markers

Just looking at the signal data however is usually not sufficient. A lot of times,
you'll want to make sure that timings are honored and the bit times are like what
you'd expect. To do so, you'll want to use cursors and time markers.

In the picture above, you can enable the cursor by clicking on the cursor button.
You can move both of its boundaries around by clicking on the blue flags in the
time scale area. The area between the two boundary lines shows the time distance
and its inverse (i.e. the frequency). If you can't see it, just zoom in until it
shows. You can also move both boundaries at the same time by dragging the label
where this information is shown.

image::pv_cursors_markers.png[]

<1> Cursors button, showing enabled state
<2> Cursor
<3> Time Marker

Time markers are static markers that you can create wherever you like on the
time scale - just double-click on it and it'll create one for you where your
mouse cursor is at the time. You can click on its label and you'll have the
option to change its name.

[NOTE]
For timing comparison purposes, you can also enable a vertical marker line that
follows your mouse cursor: _Settings_ -> _Views_ -> _Highlight mouse cursor_

[NOTE]
There is also a special kind of time marker that appears for each time the data
acquisition device has triggered. It cannot be moved and appears as a vertical
dashed line.

=== Special-Purpose Decoders

There are some decoders available that analyze the data instead of decoding it.
You can make use of them to examine various properties of the signals that are
of interest to you.

Their names are:

* Counter - counts pulses and/or groups of pulses (i.e. words)
* Guess bitrate - guesses the bitrate when using a serial protocol
* Jitter - determines the jitter (variance) of a signal
* Timing - shows the time passing between the chosen signal edges
Commit	Line	Data
1894027b SA	1	== Data Analysis
	2
	3	Once you have acquired some measurement data, it's time to have a look and see what
	4	insights you can gain from it. Usually, the first step is to look at the data as a
	5	whole, achieved by clicking the _Zoom to Fit_ button:
	6
	7	image::pv_analysis.png[]
	8
	9	<1> Zoom-to-Fit button
	10	<2> Zoom in/zoom out buttons
	11	<3> Cursors
	12	<4> Time scale (used to set up and show time markers, see below)
	13
	14	If you have located an area of interest (maybe with the help of decoders, more about
	15	that later), you can zoom in on it using the _zoom in_/_zoom out_ buttons, using the
	16	scroll wheel of your mouse or the pinch/expand gestures on your touch panel.
	17
	18	[NOTE]
	19	When a data capture is ongoing, the Zoom-to-Fit button stays active if you click it,
	20	meaning that PulseView automatically fits all data to the views until either the
	21	capture is finished or the Zoom-to-Fit button is clicked again.
	22
	23	=== Cursors and Time Markers
	24
	25	Just looking at the signal data however is usually not sufficient. A lot of times,
	26	you'll want to make sure that timings are honored and the bit times are like what
	27	you'd expect. To do so, you'll want to use cursors and time markers.
	28
	29	In the picture above, you can enable the cursor by clicking on the cursor button.
	30	You can move both of its boundaries around by clicking on the blue flags in the
	31	time scale area. The area between the two boundary lines shows the time distance
	32	and its inverse (i.e. the frequency). If you can't see it, just zoom in until it
	33	shows. You can also move both boundaries at the same time by dragging the label
	34	where this information is shown.
	35
	36	image::pv_cursors_markers.png[]
	37
	38	<1> Cursors button, showing enabled state
	39	<2> Cursor
	40	<3> Time Marker
	41
	42	Time markers are static markers that you can create wherever you like on the
	43	time scale - just double-click on it and it'll create one for you where your
	44	mouse cursor is at the time. You can click on its label and you'll have the
	45	option to change its name.
	46
	47	[NOTE]
	48	For timing comparison purposes, you can also enable a vertical marker line that
	49	follows your mouse cursor: _Settings_ -> _Views_ -> _Highlight mouse cursor_
	50
	51	[NOTE]
	52	There is also a special kind of time marker that appears for each time the data
	53	acquisition device has triggered. It cannot be moved and appears as a vertical
	54	dashed line.
	55
	56	=== Special-Purpose Decoders
	57
	58	There are some decoders available that analyze the data instead of decoding it.
	59	You can make use of them to examine various properties of the signals that are
	60	of interest to you.
	61
	62	Their names are:
	63
	64	* Counter - counts pulses and/or groups of pulses (i.e. words)
65	* Guess bitrate - guesses the bitrate when using a serial protocol
66	* Jitter - determines the jitter (variance) of a signal
67	* Timing - shows the time passing between the chosen signal edges
68