how can I plot signals in the same "X" axis without crating a new channel?

[hesparza]

After reading signal channels with Diadem and plot them in a 2D graphic, they are plotted one afte other, and I would like to plot them in the same X axis without creating a new channel. The first time I did it, it worked but now is different. Im not using timestamp, Im using just number of samples, they are in the same file with the same number of samples. Thank you in advanced for any comments

Héctor

[Brad_Turpin]

Hi Hector,

Please attach a sample data set, I can't quite make out what you mean by your description.

Brad Turpin
DIAdem Product Support Engineer
National Instruments

[hesparza]

Thank you Brand, this is a snapshot from the View area of Diadem. The file is 2.2 Mb big if you need it, please let me know and I will send you by email . Thanks again.

Héctor

[ChaosYeti]

Hi Héctor,

as I understand you, you do need a new channel, but for the display, just leave the x-channel empty - as shown in my attached image. To insert the channels by drag&drop, catch the channels individually.
That means... depending on the DIAdem version you use. v9.1 is not able to do so, v10.2 definately is.

[hesparza]

I am using v.10.2. With some files I have not problem and I do it as you mentioned; but with others   I realy do not understand why.

[ChaosYeti]

Do you have NOVALUEs in there?
I'm doing a calculation myself with script without the x-channel, and there I have to delete the NOVALUEs before doing anything with the data to not receive failure messages or screwed up results.

If so, I recommend the ChnNovHandle function 🙂

[hesparza]

No, there are no "No values" . The plot in figure is two channels with same lengh, and with real values. I want to compare  them with the same "X" axis, overlapping between them.

[ChaosYeti]

Hmm, don't you have a "time" channel somewhere in all those channels you have in the data portal? Maybe then you might take that one for "x".
By my first impressions the channels would have to start at the same spot, which they don't do.

What I don't understand is how your displayed channel "Filtered" can start so late if there are no NOVALUEs inside... have you tried it with "refresh" (menu bar "View" -> "Refresh"> or key ?

(Sometimes a reboot works, too 😉

[hesparza]

Thank you all, for your help and comments, I found out that the signal channel have an offset, I could see it in the properties. I ignore why, I would like to know if somebody knows. My data was fixed setting to 0 the offset property. Thanks again

Héctor

[Brad_Turpin]

Hi hesparza,

It sounds like you're saying that your channels are waveforms (they have a "~" to the left of them in the Data Portal), and that for one or more of your channels the "Waveform x-offset" property is not set to 0, and you're not sure why.  Well, where does your data come from?  If you do have waveforms, then you must either be acquiring the data with LabVIEW or CVI or loading the data with a DataPlugin.  What type of data file is it?  Typically if some waveforms have a non-zero offset, it means they were acquired later than the other waveforms, and the graph picture you posted would then reflect that reality by plotting the "later" data further to the right on the X axis.  You can always manually or programmatically set the offset to 0 if you want to show all the graphs starting at 0 on the X axis, as it sounds like you have already done on your end.  If the non-zero offset is just wrong, then I suggest you talk with either the programmer of the LabVIEW or CVI code that acquired the data or the programmer of the DataPlugin to discuss how that property is being set.

If you don't have waveforms, then I don't understand you yet, please explain further.

Cheers,
Brad Turpin
DIAdem Product Support Engineer
National Instruments