Replaces the data in a flash object with a new set of observations. Estimates of residual variances and the ELBO are also updated.
flash_update_data(flash, newdata, Y2_diff = NULL)A flash or flash_fit object.
The new observations. Can be a matrix, a sparse matrix of
class Matrix, or a low-rank matrix representation.
Optionally, users can supply the (summed) changes in the
squared values of the data \(y_{ij}^2\), which are needed to estimate the
residual variance parameters \(s_{ij}^2\) for simple variance structures
(i.e., when var_type is set to 0, 1, or 2). If calculating
entries \(y_{ij}^2\) from scratch is expensive, supplying an argument
to Y2_diff can greatly speed up data updates. If specified, the
argument should be a scalar
\(\sum_{i, j} \left( y_{ij}^{2 \text{(new)}} - y_{ij}^{2 \text{(old)}} \right)\)
when var_type = 0; a vector of length \(n\) with entries
\(\sum_{j = 1}^p \left( y_{ij}^{2 \text{(new)}} - y_{ij}^{2 \text{(old)}} \right)\)
when var_type = 1; or a vector of length \(p\) with entries
\(\sum_{i = 1}^n \left( y_{ij}^{2 \text{(new)}} - y_{ij}^{2 \text{(old)}} \right)\)
when var_type = 2. The argument is ignored when any other variance
structure is used.
The flash object from argument flash, with
the data modified as specified by newdata. Residual variances and
ELBO are also updated.