Variance arg in atlantis_tracer_survey_select

[pfrater]

Just out of curiousity...when random noise is added to the survey data in the function atlantis_tracer_survey_select the sigma argument is squared to produce the err_variance object within the function on line132 (which is then used as the sd argument of rnorm). I'm just wondering why this term is squared as rnorm takes standard deviation (which is the square root of variance) as the argument for how much variation to introduce in the normal distribution.

Shouldn't the sigma argument either be input directly into rnorm? Or alternatively the user could be asked for variance and then take the sqrt of that and put into rnorm

[lentinj]

Just me getting confused, I think. Feel free to push something to get rid of it.

[pfrater]

Got it. Just wanted to make sure it wasn't something else before changing. See #9.