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en:create:functions:calc [16.10.2019 20:06] (current)
admin created
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 +====== calcMean(), calcSD(), ... ======
  
 +These functions perform simple statistical calculations within the questionnaire,​ they all follow the same syntax:
 +
 +''​**calcXYZ**(array //Data//, [boolean //​Filter//​])''​
 +
 +  * //Data//\\ An array of numeric values. The values ''​false''​ and ''​null''​ are ignored in the calculation. Numbers that are stored as strings are converted to numbers.
 +  * //​Filter//​\\ If this option is set to ''​true'',​ negative values are ignored in the calculation. This is useful if raw data from SoSci Survey are used. Missing values (no response and alternative options) are coded with negative codes.
 +
 +The function returns either a floating point value (float) or ''​NULL''​ if the calculation fails (e.g. because there are no valid values).
 +
 +The following functions are available:
 +
 +  * ''​**calcMean()**''​ Calculate arithmetic mean value
 +  * ''​**calcSD()**''​ Calculate standard deviation (1/n)
 +  * ''​**calcESD()**''​ Calculate empirical standard deviation (1/(n-1), see. sample variance)
 +
 +**Tip:** If you want to directly calculate with the answers of the participant,​ use the functions ''​[[:​en:​create:​functions:​valuemean]]'',​ ''​[[:​en:​create:​functions:​valuesd]]'',​ ''​[[:​en:​create:​functions:​valuevar]]''​.
en/create/functions/calc.txt · Last modified: 16.10.2019 20:06 by admin
 
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