Simple chart with time as X-Axis

[RTSLVU]

Charts and graphs in LabView have been driving me nuts for years. What I would like to see is a simple chart (maybe even an "Express Chart") that has a single dimensional array input and a timestamp input. Values in the array would automatically be plotted on their own plot and the time stamp would be put in the X-axis starting from the left. An option to just use the current time if no timestamp was input and amount of data displayed on the X-axis can be adjusted on the fly by setting the X-axis TIME/DIV

[Dennis_Knutson]

You already have the option to pass a single dimension array and timestamp. It's  just that they have to be part of a waveform data type or cluster.

[JackDunaway]

I'm going to put my credibility on the line and say.... I had no idea you could plot arbitrary timestamps to a chart. Dennis, could you post an example? (Hence, Ravens gets Kudos too)

[Dennis_Knutson]

There is no mention of a set of arbitrary values on the x axis in the idea and in fact, it is impossible to use a chart or graph for arbitrary values as I'm sure you are aware. I did not read this idea as applying to an XY Graph.

[JackDunaway]

Perhaps I misunderstood this idea - I was voting for a chart that plots points with horizontal spacing accurate with respect to time, where data points could be plotted with arbitrary time spacings (think slow data collection, erratic data acquisition coming over a networked device, data collection that can be turned on and off...).

[tst]

Jack, it should to me like what you want is an XY chart. There's a shipping example for that (although an ugly one) and an example I posted (although an inefficient one).

I didn't understand the original idea, so I can't say how it relates to this.

[JackDunaway]

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@tst wrote:

it should to me like what you want is an XY chart

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Yes, that's probably the best description of what I thought this idea referred to. This just seems like one of those ideas that could be useful to a large enough percentage of the customer base to justify R&D's investment... you know, written once and used by a thousand customers, rather than written by a thousand customers and used once.

I'd like to get some clarification from RTSLVU before making more assumptions.

[RTSLVU]

" I was voting for a chart that plots points with horizontal spacing accurate with respect to time, where data points could be plotted with arbitrary time spacings (think slow data collection, erratic data acquisition coming over a networked device, data collection that can be turned on and off...)."

You understand me correctly, that is exactly what I need. We have many datalogers in house that come with their own software that is simple and plots masurements on the screen. Take a look at Agilent "Benchlink" software the provide with their 34967A DAQ/Switch. My coworkers and mamagers always look at me and ask "Why can't LabView do this?"

I know LabView can do this but I have not been able to figure out how.

[Dennis_Knutson]

Simple example. The Express XY Graph could also be used. You also need to set the X Scale properties to display time.

[Brian_Powell]

Just making sure you're aware that the waveform chart honors timestamps in waveform inputs.  (I think this is what Dennis was getting at with his first post.)  Here's a snippet showing single-element waveforms.  (Ignore the issue of the timing relationship between Get Time in Seconds and the Wait; this is just for illustration.)  Note that the X-spacing is not uniform.  The same would work with multiple-element waveforms, assuming the dt in each waveform is accurate.  Also note that if time goes backwards, the chart will erase and display only the latest data.  (I think.  And by "time goes backwards", I mean if waveform N has a final time that's greater than the t0 of waveform N+1.)

[donkdonk]

I fully agree that one should be able to do this!

I wondered since version 3 why it was not implemented. 

Didn't realise there is a simple solution as shown by Brian Powell (Thanks Brian).

Question: how can it be done if one wants a relative time scale, say X in seconds starting at 0 seconds (the start of your experiment)?

I mean a solution without having to bother with storing/managing history data yourself.

(I know the solution when using shift registers and an XY graph, but that's not what I mean).

I think it is a duplicate of this 😉

http://forums.ni.com/t5/LabVIEW-Idea-Exchange/Charts-with-quot-non-evenly-spaced-quot-timestamp-per-...