modFilter
imposes a hard filter for (gene expression) feature data.
modFilter(object, threshold, maximum, beta1, beta2)
An ExprsArray
object to undergo pre-processing.
A numeric scalar. The value below which to assign this value.
A numeric scalar. The value above which to assign this value.
A numeric scalar. The max - min
range above which to
include the feature. Inclusive with beta2
.
A numeric scalar. The max / min
ratio above which to
include the feature. Inclusive with beta1
.
A pre-processed ExprsArray
object.
This method reproduces the hard filter described by Deb and Reddy (2003)
for pre-processing the hallmark Golub ALL/AML dataset. This filter
first sets all values less than threshold
to threshold
and all values greater than maximum
to maximum
.
Next, this method includes only those features with (a) a range greater
than beta1
, and also (b) a ratio of maximum feature expression to
minimum feature expression greater than beta2
.