Difference between revisions of "Input.interp"

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[[Category:R tool]]
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#REDIRECT [[OpasnetUtils/Interpret]]
{{method|moderator=Jouni|stub=Yes}}
 
'''input.interp''' is an R function that interprets model inputs from a user-friendly format into explicit and exact mathematical format. The purpose is to make it easy for a user to give input without a need to worry about technical modelling details.
 
 
 
==Question==
 
 
 
What should be a list of important user input formats, and how should they be interpreted?
 
 
 
==Answer==
 
 
 
The basic feature is that if a text string can be converted to a meaningful numeric object, it will be. This function can be used when data is downloaded from [[Opasnet Base]]: if Result.Text contains this kind of numeric information, it is converted to numbers and fused with Result.
 
 
 
n is the number of iterations in the model. # is any numeric character in the text string.
 
 
 
{| {{prettytable}}
 
!Example!!Regular expression!!Interpretation !! Output in R
 
|----
 
| 12 000 ||# # || 12000. Text is interpreted as number if space removal makes it a number. || as.numeric(gsub(" ", "", Result.text))
 
|----
 
| 12,345 ||#,# || 12.345. Commas are interpreted as decimal points. || as.numeric(gsub(",", ".", Result.text)) # Note! Do not use comma as a thousand separator!
 
|----
 
| -14,23 || -# || -14.23. Minus in the beginning of entry is interpreted as minus, not a sign for a range. ||
 
|----
 
| 50 - 125 ||# - # ||Uniform distribution between 50 and 125 || data.frame(obs=1:n, result=runif(n,50,125))
 
|----
 
| -12 345 - -23,56 || || Uniform distribution between -12345 and -23.56. ||
 
|----
 
| 1 - 50 ||# - # || Loguniform distribution between 1 and 50 (Lognormality is assumed if the ratio of upper to lower is => 30) ||
 
|----
 
| 3.1 ± 1.2 or 3.1 +- 1.2||# ± # or # +- # ||Normal distribution with mean 3.1 and SD 1.2 || data.frame(obs=1:n, result=rnorm(n,3.1,1.2))
 
|----
 
| 2.4 (1.8 - 3.0) || # (# - #) ||Normal distribution with mean 2.4 and 95 % confidence interval from 1.8 to 3.0 || data.frame(obs=1:n, result=rnorm(n,2.4,(3.0-1.8)/2/1.96))
 
|----
 
| 2.4 (2.0 - 3.2) || # (# - #) ||Lognormal distribution with mean 2.4 and 95 % confidence interval from 2.0 to 3.0. Lognormality is assumed if the difference from mean to upper limit is => 50 % greater than from mean to lower limit.||
 
|----
 
| 24 - 35 (odds 5:1) || # - # (odds #:#) || Interpretation: odds is five to one that the truth is between 24 and 35. How to calculate this, I don't know yet, but there must be a prior.||
 
|----
 
|}
 

Latest revision as of 17:44, 24 January 2013