05104: Create new question type for stored calculation results, called Equation - LimeSurvey bugs, patches and feature requests

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Date Submitted

Last Update

05104

User patches

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public

2011-04-11 20:51

2012-06-21 13:22

Reporter

TMSWhite

Assigned To

TMSWhite

Priority

normal

Severity

minor

Status

closed

Resolution

fixed

Product Version

1.91RC5

Target Version

Fixed in Version

2.00

Summary

05104: Create new question type for stored calculation results, called Equation

Description

Assuming we've created a generic equation parser (see Issue 05103), create a new Question Type called "Equation".

$ia[3] (question text) would hold the equation to be parsed.

At design-time, the equation parser would validate the syntax and semantics of the equation (e.g. to ensure that it didn't try to reference values that had not yet been set).

At run-time, the equation parser would evaluate $ia[3] each time the Conditions specified it should be visited. The results of that calculation would be stored in the database, just like any other Question's results.

The results of the calculation could be either a String, a Number, or a Date. If LimeSurvey supports easy casting across those data types (e.g. store as a String, but do run-time casting of it to a Number or Boolean), then we'd only need one Equation type. If it is safer to strongly type the values, then we'd need StringEquation, LongEquation, DoubleEquation, BooleanEquation, DateEquation types.

These Equations would be used for situations where users might want to export the data and run statistics on the values computed for those equations. So, we'd want the ability to implement import/export/statistics on them.

Sometimes it is necessary to create intermediate Equations which are needed for display purposes, or branching logic, but don't need to be in an export to a statistical dataset. I've recommended that users prefix such variables with something like "nd_" to indicate that they do not contain relevant data. That way, when they export their datasets, they can use regular expression matching to exclude variables they don't care about.

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LimeSurvey build number

9992

Attached Files

Relationships

related to	05103	closed	TMSWhite	Support conditional piping/tailoring and complex calculations via embedded equation parser
related to	05288	closed	TMSWhite	Optionally replace Assessments with ExpressionManager features

Notes
(15502) TMSWhite (developer) 2011-06-19 07:52	Notes to self - Which functions would need to be edited to add an Equation question type? common_functions.php export_data_r.php export_data_spss.php admin/export_structure_lsrc.php index.php qanda.php admin/questionhandling.php admin/surveytable_functions.php admin/update/upgrade-mssql.php admin/update/upgrade-msqlnative.php admin/update/upgrade-mysql.php admin/update/upgrade-postgres.php

(15748) TMSWhite (developer) 2011-07-13 00:02 edited on: 2011-07-13 00:02	This now works in the limesurvey_dev_tms branch - revision 10498. Equations use type '*' and follow the ExpressionManager syntax. The are true questions, so the results are stored in the database, and can be used by {INSERTANS:xxx} or ExpressionManager itself.

(16566) TMSWhite (developer) 2011-10-28 23:04	This is available in >= 2.0alpha

Issue History
Date Modified	Username	Field	Change
2011-04-11 20:51	TMSWhite	New Issue
2011-05-07 11:58	c_schmitz	Status	new => acknowledged
2011-06-19 07:52	TMSWhite	Note Added: 15502
2011-06-19 18:59	TMSWhite	Relationship added	related to 05288
2011-06-19 19:03	TMSWhite	Relationship added	related to 05103
2011-07-13 00:02	TMSWhite	Note Added: 15748
2011-07-13 00:02	TMSWhite	Note Edited: 15748	View Revisions
2011-10-28 23:04	TMSWhite	Note Added: 16566
2011-10-28 23:04	TMSWhite	Status	acknowledged => resolved
2011-10-28 23:04	TMSWhite	Fixed in Version	=> 2.00
2011-10-28 23:04	TMSWhite	Resolution	open => fixed
2011-10-28 23:04	TMSWhite	Assigned To	=> TMSWhite
2012-06-21 13:22	c_schmitz	Status	resolved => closed