apply_function

AGGREGATIONS

1 Description

Generic function that applies one of BigDataStatMeth’s algebraic or statistical functions to a list of datasets in the same HDF5 group as x.

Valid func values: "QR", "CrossProd", "tCrossProd", "invChol", "blockmult", "CrossProd_double", "tCrossProd_double", "solve", "normalize", "sdmean", "descChol".

2 Usage

apply_function(x, ...)

3 Arguments

Parameter	Description
`x`	An .

4 Value

Named list with elements , , , .

5 Examples

\donttest{
fn <- tempfile(fileext = ".h5")

# Create two datasets in the same group
hdf5_create_matrix(fn, "data/A", data = matrix(rnorm(50), 5, 10))
hdf5_create_matrix(fn, "data/B", data = matrix(rnorm(50), 5, 10))

# Apply CrossProd to all datasets in the group
X   <- hdf5_matrix(fn, "data/A")
res <- apply_function(X, func = "CrossProd", out_group = "RESULTS")

hdf5_close_all()
unlink(fn)
}

6 See Also

hdf5_apply

---
title: "apply_function"
subtitle: "apply_function"
---

<span class="category-badge aggregations">AGGREGATIONS</span>

## Description

Generic function that applies one of BigDataStatMeth's algebraic or
statistical functions to a list of datasets in the same HDF5 group as
`x`.

Valid `func` values: `"QR"`, `"CrossProd"`,
`"tCrossProd"`, `"invChol"`, `"blockmult"`,
`"CrossProd_double"`, `"tCrossProd_double"`, `"solve"`,
`"normalize"`, `"sdmean"`, `"descChol"`.

## Usage

```r
apply_function(x, ...)
```
## Arguments

::: {.param-table}
| Parameter | Description |
|-----------|-------------|
| `x` | An \code{HDF5Matrix}. |
:::

## Value

::: {.return-value}
Named list with elements \code{filename}, \code{out_group},
  \code{func}, \code{datasets}.

:::
## Examples
```{r}
#| eval: false
#| warning: false

\donttest{
fn <- tempfile(fileext = ".h5")

# Create two datasets in the same group
hdf5_create_matrix(fn, "data/A", data = matrix(rnorm(50), 5, 10))
hdf5_create_matrix(fn, "data/B", data = matrix(rnorm(50), 5, 10))

# Apply CrossProd to all datasets in the group
X   <- hdf5_matrix(fn, "data/A")
res <- apply_function(X, func = "CrossProd", out_group = "RESULTS")

hdf5_close_all()
unlink(fn)
}

```
## See Also

::: {.see-also}
`hdf5_apply`

:::