[Kst] ASCII data - confusion about multiple plots

Wed Feb 3 23:57:03 UTC 2016

Number of data points varies tremendously, depending on how long we were
collecting data, and what sample rate was... accelerometer data is sampled
at 4 hz, which is 12 points per second; if run over a weekend (a common
sampling period) that would be about 3 million points.

I suspect that kst2 won't have trouble with this; I've already been using
it to plot 30,000 points, which it handles almost instantly!!

On Wed, Feb 3, 2016 at 3:53 PM, Barth Netterfield <
netterfield at astro.utoronto.ca> wrote:

> Only non-redundant lines ever get sent to the graphics card, so that
> really won't matter.
> How many points are you plotting?
>
> On Wed, Feb 3, 2016 at 6:50 PM, Daniel Miller <dmiller at vitalconnect.com>
> wrote:
>
>> huh... yeah, that might well work!!  It'll be plotting three times as
>> much data as it really is receiving, but what the heck, we have Nvidia
>> graphics cards...
>>
>> Thanks, I'll try that!!
>>
>>
>> On Wed, Feb 3, 2016 at 3:48 PM, Ben Lewis <benlewis003 at gmail.com> wrote:
>>
>>> Hi Dan,
>>>
>>> It sounds like each channel has its own sample rate (or is asynchronous).
>>>
>>> In cases like this I use the channel with the highest sample rate for
>>> the time stamp. Then for all other channels I use the old value until it is
>>> updated.
>>>
>>> For example
>>>
>>> timestamp, data_x, data_y, data_z
>>> 0, 10, 10, 10
>>> 1, 20, 10, 10
>>> 2, 30, 20, 10
>>> 3, 40, 20, 10
>>> 4, 50, 30, 10
>>> 5, 60, 30, 10
>>> 6, 70, 40, 10
>>> 7, 80, 40, 10
>>> 8, 90, 50, 10
>>> 9, 100, 50, 20
>>>
>>> In this case data_x updates at the fast rate, data_y updates at half of
>>> data_x and data_y updates at 1/10 of data_x.
>>>
>>> Would this work in your case?
>>>
>>> Regards, Ben
>>>
>>>
>>> On 4/02/2016 10:36 AM, Daniel Miller wrote:
>>>
>>> hmmm... well, I prefer lines to points in kst2; the plots with points
>>> are sort of hard to utilize, but I'll take a look at it and see what it
>>> looks like.
>>>
>>> Alternately, is there some way to input three data files, but have them
>>> plotted on one plot??  I haven't really seen that in the manual either...
>>>
>>>
>>> On Wed, Feb 3, 2016 at 3:33 PM, Barth Netterfield <
>>> netterfield at astro.utoronto.ca> wrote:
>>>
>>>> As you have sort of figured out, kst's data source model will want you
>>>> to have 3 different ascii files in this case.
>>>>
>>>> But, if you just want to plot points, and not lines, you can use NaN as
>>>> your bad data marker.
>>>>
>>>> On Wed, Feb 3, 2016 at 6:30 PM, Daniel Miller <
>>>> <dmiller at vitalconnect.com>dmiller at vitalconnect.com> wrote:
>>>>
>>>>> I have kst2 working with single plot stream... that works very
>>>>> nicely.  At this point, I'm using space as separator between fields.
>>>>>
>>>>> However, we have a couple of data streams which contain multiple data
>>>>> (x, y, z); in this situation, what our data would look like is ( timestamp,
>>>>> data), but the data would be one of { data_x, data_y, data_z }.  In other
>>>>> words, the data stream that I receive from the hardware, delivers data_x,
>>>>> data_y, data_z in separate messages, with different timestamps.
>>>>>
>>>>> I want kst2 to read this ascii data file and plot 3 separate graphs on
>>>>> one plot.
>>>>> I'm a little confused about how to do this, though;
>>>>>
>>>>> for example, say I have a line with data for data_z; this will look
>>>>> something like:
>>>>> timestamp data_z
>>>>> however, I want one file to contain data for all three streams, so I'm
>>>>> guessing I need to have empty fields for the not-relevant data; maybe
>>>>> something like:
>>>>> timestamp unused_x unused_y data_z
>>>>> timestamp unused_x data_y unused_z
>>>>> etc...
>>>>>
>>>>> So first off, I probably have to use a different separator rather than
>>>>> space for separator; but even with comma, I still have a problem; for
>>>>> example:
>>>>>
>>>>> timestamp, 0, 0, data_z
>>>>> timestamp, 0, data_y, 0
>>>>>
>>>>> Except that in some cases, 0 is valid data; I *think* I need some way
>>>>> to represent "invalid data" in the unused fields.
>>>>>
>>>>> Is this understandable??  How do I handle this??
>>>>> Dan Miller
>>>>>
>>>>> _______________________________________________
>>>>> Kst mailing list
>>>>> Kst at kde.org
>>>>> https://mail.kde.org/mailman/listinfo/kst
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> C. Barth Netterfield
>>>> University of Toronto
>>>> 416-845-0946
>>>>
>>>>
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>>>>
>>>
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>
>
> --
> C. Barth Netterfield
> University of Toronto
> 416-845-0946
>
>
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