convertIncrement | R Documentation |
Adjusts the intervals of census data that is not annual to report output on population dynamics on an annual basis.
convertIncrement(dataf, nYrs = 1)
dataf |
a dataframe with columns ‘size’ ‘sizeNext’, ‘exactDate’, ‘exactDateNext’. |
nYrs |
the number of years between sequential measurements (i.e. if census interval is 5, nYrs = 5, if census interval is 3 times a year, nYrs = 0.333). |
In some data sets the time interval between census measurements can be different than one year. In some species demographic information is recorded several times within a year, while in others, particularly in "slow-living" species (e.g. trees) the census frequency is greater than one year and/or vary across intervals. This function takes a data frame dataf
and uses columns with the term extractData
to adjust the size increment to the number of years given in nyears
. It defaults to annual.
Returns the adjusted increments.
C. Jessica E. Metcalf, Sean M. McMahon, Roberto Salguero-Gomez, Eelke Jongejans & Cory Merow.
Sampling three times/year (nYrs = 0.333): Smith, Caswell & Mettler-Cherry. Stochastic flood and precipitation regimes and the population dynamics of a threatened floodplain plant. Ecological Applications 15, p1036-1052.
Sampling every five years (nYrs = 5): van Mantgem & Stepheson. 2005. The accuracy of matrix population model projections for coniferous trees in the Sierra Nevada, California. Journal of Ecology 93, p737-747.
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