get_HDF5_scalar_sd

C++ Function Reference

1 Signature

double BigDataStatMeth::get_HDF5_scalar_sd(BigDataStatMeth::hdf5Dataset *dsA, bool bparal, Rcpp::Nullable< int > wsize, Rcpp::Nullable< int > threads)

2 Description

Standard deviation of all elements of an HDF5 matrix.

3 Parameters

dsA (BigDataStatMeth::hdf5Dataset *): Open HDF5 dataset.
bparal (bool): Enable OpenMP parallelism.
wsize (Rcpp::Nullable< int >): Block size (NULL = auto).
threads (Rcpp::Nullable< int >): Thread count (NULL = auto).

4 Returns

Scalar standard deviation.

5 Details

Equivalent to sd(as.vector(X)) — uses Bessel’s correction (N-1).

6 Call Graph

7 Source Code

Implementation

File: inst/include/hdf5Algebra/matrixAggregations.hpp • Lines 1178-1189

inline double get_HDF5_scalar_sd(BigDataStatMeth::hdf5Dataset* dsA,
                                  bool bparal,
                                  Rcpp::Nullable<int> wsize,
                                  Rcpp::Nullable<int> threads)
{
    try {
        return std::sqrt(get_HDF5_scalar_var(dsA, bparal, wsize, threads));
    } catch (std::exception& e) {
        throw std::runtime_error(std::string("c++ exception get_HDF5_scalar_sd: ")
                                 + e.what());
    }
}

8 Usage Example

#include "BigDataStatMeth.hpp"

// Example usage
auto result = get_HDF5_scalar_sd(...);

---
title: "get_HDF5_scalar_sd"
subtitle: "C++ Function Reference"
---

## Signature

```cpp
double BigDataStatMeth::get_HDF5_scalar_sd(BigDataStatMeth::hdf5Dataset *dsA, bool bparal, Rcpp::Nullable< int > wsize, Rcpp::Nullable< int > threads)
```

## Description

Standard deviation of all elements of an HDF5 matrix.

## Parameters

- `dsA` (`BigDataStatMeth::hdf5Dataset *`): Open HDF5 dataset.
- `bparal` (`bool`): Enable OpenMP parallelism.
- `wsize` (`Rcpp::Nullable< int >`): Block size (NULL = auto).
- `threads` (`Rcpp::Nullable< int >`): Thread count (NULL = auto).

## Returns

Scalar standard deviation.

## Details

Equivalent to sd(as.vector(X)) — uses Bessel's correction (N-1).

## Call Graph

::: {.diagram-section}
<object type="image/svg+xml" data="images/namespace_big_data_stat_meth_a97ddbcc269a29d368a3d91f8b3bb50c6_cgraph.svg" class="class-diagram">
  <img src="images/namespace_big_data_stat_meth_a97ddbcc269a29d368a3d91f8b3bb50c6_cgraph.svg" alt="Function dependencies"/>
</object>
:::

## Source Code

::: {.callout-note collapse="true"}
### Implementation

**File:** `inst/include/hdf5Algebra/matrixAggregations.hpp` • **Lines 1178-1189**

```cpp
inline double get_HDF5_scalar_sd(BigDataStatMeth::hdf5Dataset* dsA,
                                  bool bparal,
                                  Rcpp::Nullable<int> wsize,
                                  Rcpp::Nullable<int> threads)
{
    try {
        return std::sqrt(get_HDF5_scalar_var(dsA, bparal, wsize, threads));
    } catch (std::exception& e) {
        throw std::runtime_error(std::string("c++ exception get_HDF5_scalar_sd: ")
                                 + e.what());
    }
}
```
:::

## Usage Example

```cpp
#include "BigDataStatMeth.hpp"

// Example usage
auto result = get_HDF5_scalar_sd(...);
```