age.apply {myTAI}

Age Category Specific apply Function

Description

This function performs the split-apply-combine methodology on Phylostrata or Divergence Strata stored within the input ExpressionSet.

This function is very useful to perform any phylostratum or divergence-stratum specific analysis.

Usage

age.apply(ExpressionSet, FUN, ..., as.list = FALSE)

Arguments

ExpressionSet

a standard PhyloExpressionSet or DivergenceExpressionSet object.

FUN

a function to be performed on the corresponding expression matrix of each phylostratum or divergence-stratum.

...

additional arguments of FUN.

as.list

a boolean value specifying whether the output format shall be a matrix or a list object.

Details

This function uses the split function to subset the expression matrix into phylostratum specific sub-matrices. Internally using lapply, any function can be performed to the sub-matrices. The return value of this function is a numeric matrix storing the return values by FUN for each phylostratum and each developmental stage s. Note that the input FUN must be an function that can be applied to a matrix (e.g., colMeans or RE). In case you use an an anymous function you coud use function(x) apply(x , 2 , var) as an example to compute the variance of each phylostratum and each developmental stage s.

Value

Either a numeric matrix storing the return values of the applied function for each age class or a numeric list storing the return values of the applied function for each age class in a list.

Author(s)

Hajk-Georg Drost

See Also

split, tapply, lapply, RE, REMatrix

Examples

 
 # source the example dataset
 data(PhyloExpressionSetExample)
 
# Example 1
# get the relative expression profiles for each phylostratum
age.apply(PhyloExpressionSetExample, RE)

# this is analogous to 
REMatrix(PhyloExpressionSetExample)
# Example 2
# compute the mean expression profiles for each phylostratum
age.apply(PhyloExpressionSetExample, colMeans)

# Example 3
# compute the variance profiles for each phylostratum
age.apply(PhyloExpressionSetExample, function(x) apply(x , 2 , var))

# Example 4
# compute the range for each phylostratum
# Note: in this case, the range() function returns 2 values for each phylostratum
# and each developmental stage, hence one should use the argument 'as.list = TRUE'
# to make sure that the results are returned properly 
age.apply(PhyloExpressionSetExample, function(x) apply(x , 2 , range), as.list = TRUE)