[Nexus] Correct way to specify multiple signals

Tobias Richter Tobias.Richter at esss.se
Thu Jan 11 09:24:32 GMT 2018

Hi Armando,

First of all: With the new scheme where the attributes belong to the NXdata group there are no “,” separated lists. That scheme uses attribute arrays (for axes). I’ve just made that yet a bit clearer in the NXdata base class documentation. Hope that helps.

Otherwise there is currently no provision for plotting multiple things out of a single NXdata. If the axes of multiple NXdata groups coincide, an application would be free to plot them into the same coordinate system. 
For signals with 2 or more dimensions it is not obvious what should be done. Keeping the generic case simple and clean makes sense to me.

Best wishes,

On 11/01/2018, 10:03, "NeXus on behalf of V. Armando Solé" <nexus-bounces at shadow.nd.rl.ac.uk on behalf of sole at esrf.fr> wrote:

    Happy New Year!
    We would like to store in a single NXdata the axes and more than one
    signal sharing the same axes. The goal is to be able to plot, for
    instance, a curve and the fitted curve. With the old method where the
    attributes were associated to datasets, we were using the approach
    signal="1", signal="2",... I know that was never wrote but it was clear
    that use was quite common.
    With the new NXdata where the attributes belong to the groups, what is
    the correct approach to specify multiple signals? I would expect the
    same approach as when specifying multiple axes (that means "," separated
    dataset names) but I would appreciate confirmation because we are
    implementing it...
    Best wishes,
    NeXus mailing list
    NeXus at nexusformat.org

More information about the NeXus mailing list