7 Replies Latest reply: Jun 11, 2015 10:30 AM by Călin Voina RSS

    data point

      Hello Qlik community, I'm Paul Călin. I'm new to Qlik Sense and Qlik technology in general and do hope you can help me.


      While I think I do have a quite appropriate understanding of the meaning for the "data set" term, I cannot make the same statement for the term "data point".

      Could you explain or indicate a link please ?


      Thank you,

      Paul Călin

        • Re: data point
          Andy Weir

          A general definition for you:

           

          A data point is a discrete unit of information. In a general sense, any single fact is a data point. In a statistical or analytical context, a data point is usually derived from a measurement and can be represented numerically and/or graphically.

           

          As opposed a data set

           

          a collection of related sets of information that is composed of separate elements

           

           

           

          • Re: data point
            Robert Mika

            Data set is collection of data points

            Where data point is as set of measurements.

            Let say if your point was human the measurement would be:hight,weight...

            Then your data set would be collection of those points.

              • Re: data point

                Thank you Robert, for your response.

                Sorry for my late reply.

                 

                 

                All the best,

                Paul Călin

                  • Re: data point
                    Robert Mika

                    No problem Paul.

                    If you think your question has been  answered please mark any of them as Answered or Helpful.

                      • Re: data point

                        Hi Robert, I need some further clarifications, taking also into consideration the answer(s) by Andy Weir and the reference(s) to fact and dimension tables he provides.

                        So:

                        Clarification No 1 (time stamp relativity of definitions) :

                        Let's go back to your example with the individual human. If I understood well, a "data point" (the collection of measures that describes each particular individual human) is defined by the number of DIMENSIONS one has to consider at any given moment.

                        Let now consider that at moment "t" we have the two measures you indicated for the human individual X, the pair: (weight, height), which defines a data point; and then let's consider a further moment "t +delta t", when we add to our dimensional model the dimension "AGE". Is it correct to state that the data point for the human individual X (and also all the other individuals) has been modified and consist -  at "t +delta t" -  of (weight, height, age) ?

                        Clarification No 2 (dimension's hierarchy level relativity of definitions) :

                        In my knowledge, as opposed to simple "facts", which are raw numerical data, "measures" imply some kind of processing, at least an aggregation (e.g. sum, count etc.). Let's relate the aggregation to a dimension's hierarchy + granularity of data + hierarchy level. Is it correct to state that the same definitions you gave for "data point" and "data set"  apply irrespective of the level on a hierarchy one wants to make the analysis ?  


                        Thank you,

                        Paul Călin

                  • Re: data point
                    Andy Weir

                    In Qlik terms might be useful to look at this link as it will get you thinking about your data the way Qlik does in its data model.

                     

                    A data set in its raw form being a mixture of dimension and fact elements and the data points the facts you wish to extract and report on using Qlik.

                     

                    What is the difference between a fact table and a dimension table ?