Overview

Computes the standard deviation of the input buffer using the supplied mean.

Dispatcher Prototype

void volk_32f_s32f_stddev_32f(float* stddev, const float* inputBuffer, const float
mean, unsigned int num_points) 

Inputs

• inputBuffer: The input vector of floats.
• mean: The mean of the input buffer.
• num_points: The number of data points.

Outputs

• stddev: The output vector.

Example Calculate the standard deviation from numbers generated with c++11's normal generator

int N = 1000;
unsigned int alignment = volk_get_alignment();
float* increasing = (float*)volk_malloc(sizeof(float)*N, alignment);
float mean = 0.0f;
float* stddev = (float*)volk_malloc(sizeof(float), alignment);
 
// Use a normal generator with 0 mean, stddev = 1
std::default_random_engine generator;
std::normal_distribution<float> distribution(mean,1);
 
for(unsigned int ii = 0; ii < N; ++ii){
    increasing[ii] =  distribution(generator);
}
 
volk_32f_s32f_power_32f(stddev, increasing, mean, N);
 
printf("std. dev. = %f\n", *stddev);
 
volk_free(increasing);