# svrng_new_normal_distribution_[float|double]/svrng_update_normal_distribution_[float|double]

Allocates and initializes constants for the normal distribution with specified parameters

## Syntax

svrng_distribution_t svrng_new_normal_distribution_float( float mean, float stddev )

svrng_distribution_t svrng_new_normal_distribution_double( double mean, double stddev )

svrng_distribution_t svrng_update_normal_distribution_float( svrng_distribution_t distr, float mean, float stddev )

svrng_distribution_t svrng_update_normal_distribution_double( svrng_distribution_t distr, double mean, double stddev )

## Input Parameters

mean | Mean value of the normal distribution.
stddev | Standard deviation of the normal distribution
distr | Pointer to the distribution to be updated

## Description

The svrng_new_normal_distribution_[float|double] functions allocate memory for a normal distribution of either 32- or 64-bit floating pont numbers with the specified mean and positive, real stddev using the ICDF method. The function pre-computes and broadcasts loop-invariant constants required for vector generation. The svrng_update_normal_distribution_[float|double] functions give the same result, but by modifying existing distributions instead of allocating memory for new distributions.

## Status flags set

Name | Description
--- | ---
SVRNG_STATUS_ERROR_MEMORY_ALLOC | Memory allocation failure
SVRNG_STATUS_ERROR_BAD_PARAM2 | Bad parameter: stddev
SVRNG_STATUS_ERROR_BAD_DISTR | Bad distribution (NULL pointer)

## Return Values

A pointer to the distribution created or updated by the function, or NULL on error.

Parent topic: Distribution Initialization and Finalization