martincurveb: Calculate the particle flux attenuation constant via the...
In kevans27/aqeco: Basic Functions for Aquatic Ecologists

Description Usage Arguments Value Author(s) Examples

Solves for b according to:

fz = fz0*(z/z0)^(-b)

Intakes two vectors: depths and flux and optional reference depths and target depths. The function will return 5 variables, in order: min, max, mean, median, allvals

If you data is in excel, be sure to download the file into a dataframe, then open that dataframe to figure out the names of the columns you are interested in or rename columns. This will be easiest with a worksheet that only contains columns of data. Ex:

library(gdata)

mydata = read.xls("mydata.xls") #Reads from the first sheet only

1	martincurveb(des, flu, rds, tds)

`des`	Vector that contains all depth data. Needs to be the same length as "fluxes".
`flu`	Vector that contains all flux data. Needs to be the same length as "depth".
`rds`	Optional specific reference depth data. Can be a single value or vector. If you include rds, you need to also include tds.
`tds`	Optional specific target depth data. Can be a single value or vector. If you include tds, you need to also include rds.

Returns a list of five values: "Minimum" b value, "Maximum", "Mean", "Median", and "AllVals" (which is all calculated b values).

`Minimum`	Single numeric minimum b value
`Maximum`	Single numeric maximum b value
`Mean/Average`	Single numeric mean b value
`Median`	Single numeric median b value
`AllVals`	List of all numeric calculated b values

Kate Evans, University of Montana/Flathead Lake Biological Station

#Samples taken from 3 depths with two samples each.
#Checking all samples against any deeper samples.
depth <- c(150, 150, 300, 300, 500, 500)
flux <- c(500, 480, 340, 300, 240, 250)
martincurveb(depth, flux)

#Same samples as above (3 depths with two samples each),
#but only comparing the shallowest depth against the two deeper groups.
depth <- c(150, 150, 300, 300, 500, 500)
flux <- c(500, 480, 340, 300, 240, 250)
martincurveb(depth, flux, rds = c(300, 500), tds = 150)