bmass-class: Class "bmass" for mature and immature biomass
In flr/FLEDA: Exploratory Data Analysis for FLR

Description Creating objects from the class Slots Extends Methods Details See Also Examples

This class encapsulates results of a mature (mb) and immature (ib) biomass method.

Objects of this classe should be created with a call to the creator function bmass(object, ...), where object must be of class "FLStock" and ... can be used to pass trim arguments to the creator funtion.

.Data: Object of class "FLQuants" with a mb component and a ib component.
names: Names of the list elements. character.
desc: Description of the object. character.
lock: Lock mechanism, if turned on the length of the list can not be modified by adding or removing elements. logical.

Code: .Data desc lock names

Class "FLQuants", directly.

Inherits from "FLQuants".

Considering C_{ay}, the catch in numbers, W_{ay}, the mean weight and M_{ay}, the proportion of mature fish, at age a=1,…,A and year y=1,…,Y obtained e.g. from a "FLStock" object, the computations of bmass are:

mb:

MB_{y}=∑_{a}{C_{ay}*W_{ay}*M_{ay}}

ib:

IB_{y}=∑_{a}{C_{ay}*W_{ay}*(1-M_{ay})}

FLQuant-class, trim, logr-class

data(ple4)
# compute mature and immature biomass
ple4.bmass <- bmass(ple4)
# tune plot
ttl <- list(label="Trends in biomass for mature and immature plaice in IV", cex=1)
yttl <- list(label="relative biomass", cex=0.8)
xttl <- list(cex=0.8)
ax <- list(cex=0.8)
akey <- simpleKey(text=c("mature", "immature"), points=FALSE, lines=TRUE)
# plot
xyplot(data~year, data=ple4.bmass, type="l", main=ttl,
       key=akey, ylab=yttl, xlab=xttl, scales=ax)