Control number of fraction digits diplayed

[kvistgaard]

To my knowledge, SPARQL doesn't have a way to control the number of fraction digits displayed. And even if it had, it would've been a waste of computation at the wrong end. Yet, in many cases, it would be nice to be able to control the number of fraction digits displayed, instead of getting something like this:

without using an implementation-dependent solution such as bif:sprintf

[MathiasVDA]

What are you suggestion? Something that makes yasgui behave based on some comment that you add in the query? Or I think I can pretty easily add a setting to the table viewer where you can specify a fixed number of decimals for every xsd:float,xsd:double and xsd:decimal column.

Here are some snippets that I use for controlling number output:

        BIND(CONCAT("NO", 
            SUBSTR(CONCAT("00000", ?designator_plc_number), 
                STRLEN(CONCAT("00000", ?designator_plc_number)) - 4)) 
            AS ?designator_plc_entry)

BIND(round(xsd:decimal(xsd:double(?x_coordinate_str))*1000)/1000 AS ?x_coordinate)

I never had the use case where I needed to have an exact number of string decimals so I tried to create a snippet and it looks pretty ugly:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

SELECT *
WHERE {
  VALUES ?v { 0.123456789 0.1 0.234 5 }
  BIND (str(floor(?v * 100) / 100) AS ?v_floored_str)
  BIND (IF(CONTAINS(?v_floored_str, "."), ?v_floored_str, CONCAT(?v_floored_str, ".")) AS ?normalized)
  BIND (IF(CONTAINS(?normalized, "."), STRLEN(?normalized) - STRLEN(STRBEFORE(?normalized, ".")) - 1, 0) AS ?count_of_v_decimals)
  BIND (CONCAT(?normalized, substr("00", 1, 2 - ?count_of_v_decimals)) AS ?formatted)
}

[kvistgaard]

Indeed, it is not something that should be handled in SPARQL. That's why, adding a setting in the viewer will be useful.

[MathiasVDA]

OK, I understand, I'll look into adding this when there's some time