```/* vectorops.c
* Operations on vectors of floats or doubles.
*
* DSet(), FSet()       - set all items in vector to value.
* DScale(), FScale()   - multiply all items in vector by scale
* DSum(), FSum()       - return sum of values in vector
* DCopy(), FCopy()     - set vec1 to be same as vec2.
* DDot(), FDot()       - return dot product of two vectors.
* DMax(), FMax()       - return value of maximum element in vector
* DMin(), FMin()       - return value of minimum element in vector
* DArgMax(), FArgMax() - return index of maximum element in vector
* DArgMin(), FArgMin() - return index of minimum element in vector
*
* DNorm(), FNorm()     - normalize a probability vector of length n.
* DLog(), FLog()       - convert to log probabilities
* DExp(), FExp()       - convert log p's back to probabilities
* DLogSum(), FLogSum() - given vector of log p's; return log of summed p's.
*
* SRE, Tue Oct  1 15:23:25 2002 [St. Louis]
* CVS \$Id: vectorops.c,v 1.1 2002/10/09 14:26:09 eddy Exp)
*/

#include <stdlib.h>
#include <math.h>
#include <float.h>
#include "vectorops.h"

void
DSet(double *vec, int n, double value)
{
int x;
for (x = 0; x < n; x++) vec[x] = value;
}

void
FSet(float *vec, int n, float value)
{
int x;
for (x = 0; x < n; x++) vec[x] = value;
}

void
DScale(double *vec, int n, double scale)
{
int x;
for (x = 0; x < n; x++) vec[x] *= scale;
}

void
FScale(float *vec, int n, float scale)
{
int x;
for (x = 0; x < n; x++) vec[x] *= scale;
}

double
DSum(double *vec, int n)
{
double sum = 0.;
int    x;
for (x = 0; x < n; x++) sum += vec[x];
return sum;
}

float
FSum(float *vec, int n)
{
float sum = 0.;
int   x;
for (x = 0; x < n; x++) sum += vec[x];
return sum;
}

void
DAdd(double *vec1, double *vec2, int n)
{
int x;
for (x = 0; x < n; x++) vec1[x] += vec2[x];
}

void
FAdd(float *vec1, float *vec2, int n)
{
int x;
for (x = 0; x < n; x++) vec1[x] += vec2[x];
}

void
DCopy(double *vec1, double *vec2, int n)
{
int x;
for (x = 0; x < n; x++) vec1[x] = vec2[x];
}

void
FCopy(float *vec1, float *vec2, int n)
{
int x;
for (x = 0; x < n; x++) vec1[x] = vec2[x];
}

double
DDot(double *vec1, double *vec2, int n)
{
double result = 0.;
int x;
for (x = 0; x < n; x++) result += vec1[x] * vec2[x];
return result;
}

float
FDot(float *vec1, float *vec2, int n)
{
float result = 0.;
int x;
for (x = 0; x < n; x++) result += vec1[x] * vec2[x];
return result;
}

double
DMax(double *vec, int n)
{
int i;
double best;

best = vec[0];
for (i = 1; i < n; i++)
if (vec[i] > best) best = vec[i];
return best;
}

float
FMax(float *vec, int n)
{
int   i;
float best;

best = vec[0];
for (i = 1; i < n; i++)
if (vec[i] > best) best = vec[i];
return best;
}

double
DMin(double *vec, int n)
{
int i;
double best;

best = vec[0];
for (i = 1; i < n; i++)
if (vec[i] < best) best = vec[i];
return best;
}

float
FMin(float *vec, int n)
{
int   i;
float best;

best = vec[0];
for (i = 1; i < n; i++)
if (vec[i] < best) best = vec[i];
return best;
}

double
DArgMax(double *vec, int n)
{
int i;
int best = 0;

for (i = 1; i < n; i++)
if (vec[i] > vec[best]) best = i;
return best;
}

float
FArgMax(float *vec, int n)
{
int i;
int best = 0;

for (i = 1; i < n; i++)
if (vec[i] > vec[best]) best = i;
return best;
}

double
DArgMin(double *vec, int n)
{
int i;
int best = 0;
for (i = 1; i < n; i++)
if (vec[i] < vec[best]) best = i;
return best;
}

float
FArgMin(float *vec, int n)
{
int   i;
int   best = 0;

for (i = 1; i < n; i++)
if (vec[i] < vec[best]) best = i;
return best;
}

void
DNorm(double *vec, int n)
{
int    x;
double sum;

sum = DSum(vec, n);
if (sum != 0.0) for (x = 0; x < n; x++) vec[x] /= sum;
else            for (x = 0; x < n; x++) vec[x] = 1. / (double) n;
}

void
FNorm(float *vec, int n)
{
int    x;
float  sum;

sum = FSum(vec, n);
if (sum != 0.0) for (x = 0; x < n; x++) vec[x] /= sum;
else            for (x = 0; x < n; x++) vec[x] = 1. / (float) n;
}

void
DLog(double *vec, int n)
{
int x;
for (x = 0; x < n; x++)
if (vec[x] > 0.) vec[x] = log(vec[x]);
else vec[x] = -DBL_MAX;
}

void
FLog(float *vec, int n)
{
int x;
for (x = 0; x < n; x++)
if (vec[x] > 0.) vec[x] = log(vec[x]);
else vec[x] = -FLT_MAX;
}

void
DExp(double *vec, int n)
{
int x;
for (x = 0; x < n; x++) vec[x] = exp(vec[x]);
}

void
FExp(float *vec, int n)
{
int x;
for (x = 0; x < n; x++) vec[x] = exp(vec[x]);
}

float
DLogSum(double *vec, int n)
{
int x;
double max, sum;

max = DMax(vec, n);
sum = 0.0;
for (x = 0; x < n; x++)
if (vec[x] > max - 50.)
sum += exp(vec[x] - max);
sum = log(sum) + max;
return sum;
}

float
FLogSum(float *vec, int n)
{
int x;
float max, sum;

max = FMax(vec, n);
sum = 0.0;
for (x = 0; x < n; x++)
if (vec[x] > max - 50.)
sum += exp(vec[x] - max);
sum = log(sum) + max;
return sum;
}

```