Bug 497924

Summary: No calculations possible with date values in functions
Product: [Applications] LabPlot2 Reporter: RG <robgruebler>
Component: frontendAssignee: Alexander Semke <alexander.semke>
Status: CONFIRMED ---    
Severity: normal    
Priority: NOR    
Version First Reported In: 2.11.1   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Image "Function Values - LabPlot" and Project File
Function Values - LabPlot
Project File "LB_Is05.lml"

Description RG 2024-12-26 21:30:22 UTC
Created attachment 176891 [details]
Image "Function Values - LabPlot" and Project File

Description
============
For example, it is not possible to calculate the current age from the date of birth and the current date, as the date is apparently regarded as non-numerical.
My use case is simple: continuous measurement of infant weight and visualisation of weight development in the WHO Child Growth Standards Charts.

Steps to Reproduce
===================
1.	Start LabPlot
2.	Open project LB_Is05.lml
3.	Select spreadsheet column “Age_days”
4.	Context menu/Generate Data/ Function Values
5.	Try to select “Date” for variable “x”

(see image "LPIS05_01_FuncVals.jpg")
 
Actual Result
============
Selecting "Date" is not possible.

Expected Result
==============
Allow calculations with Datetime values 

My System
=========
Win10 Pro 64 bit, German
LabPlot V 2.11.1,  Language=English
Comment 1 RG 2024-12-26 21:36:07 UTC
Created attachment 176892 [details]
Function Values - LabPlot
Comment 2 RG 2024-12-26 21:38:16 UTC
Created attachment 176893 [details]
Project File "LB_Is05.lml"