Computational Memory Lab: Simulation Libraries

First, here's a list of all of the overloaded operators that are defined in the library. The defined operators can be used in the same way that you would use the operators for integers and floating points.

*result*	*operation*	*action*
boolean	vector = = vector	equality
boolean	matrix = = matrix	equality
boolean	vector != vector	inequality
boolean	matrix != matrix	inequality
vector	vector + vector	item-wise addition
matrix	matrix + matrix	item-wise addition
vector	vector - vector	item-wise subtraction
matrix	matrix - matrix	item-wise subtraction
vector	double * vector	mult all items by double
vector	vector * double	mult all items by double
matrix	vector * vector	outer product
vector	matrix * vector	matrix product
matrix	matrix * matrix	matrix multiplication
matrix	double * matrix	mult all items by double
matrix	matrix * double	mult all items by double
double	vector % vector	dot product
vector	vector & vector	convolution
vector	vector & int	self convolution int times
vector	vector \| vector	correlation
vector	vector \| int	self correlation int times
vector	vector \|\| vector	concatenation

There is also a number of other functions that can be called on vectors and matrices. Briefly, here is a list of them and their syntaxes.

void vector.zero()sets all the items in a vector to 0

double vector.magnitude()returns the magnitude of the vector, i.e. the sum of all of the elements

double vector.variance()returns the variance of the vector

double vector.std_err()returns the standard error of the vector

void vector.normalize()modifies the elements of the vector such that V[i] = V[i] / magnitude(V)

void vector()involves the vector in place

void vector.item()sets all the elements to random values drawn from a gaussian distribution

void vector.perturb(double rho)perturbs the vector using rho as the correlation

vector vector.copy()makes a copy of the data in the vector. If you have two vectors, old and new, and want to make new just like old with just a few minor changes, use new = copy(old) rather than just new = old

vector center_pad(vector v, long int i)center-pada vector v to have a size of i

long int matrix.get_rows()returns the number of rows in the matrix

long int matrix.getcolumns()returns the number of columns in the matrix

void matrix.zero()sets all elements of in the matrix to have a value of 0

void matrix.print(char *name)prints out the matrix, one row per line. Be careful using this on a large matrix, as it will print out the whole thing. It uses name as the title to print before it prints out the data.

Sample Program

#include "vecmat.h"

const int LEX_SIZE = 50; const int DIMENTIONALITY = 1000; const int TOTAL_TO_TRY = 10; //How many words to try and match once const int TOTAL_RUNS = 5;

void main(void) {

vector *lex = new vector[LEX_SIZE]; vector combined(DIMENTIONALITY); double dp; //to store the value of the dot-product int i; //counter variable int words_in_mem; //how many words to try at once int run;

for (i = 0; i < LEX_SIZE; i++) {

lex[i] = copy(tmp_vec); //set the size of the vector lex[i].item(); //put random elements in the vector

}

for (run = 0; run < TOTAL_RUNS; run++) {

for (words_in_mem = 0; words_in_mem < TOTAL_TO_TRY; words_in_mem++) {

cout << "WORDS TESTED: " << words_in_mem << "." << endl; combined.zero(); //zero out the combined vector //set up the combined vector to probe on for (i = 0; i < (words_in_mem + 5); i++)

combined = combined + lex[i]; //note that we can't use += because it is not overloaded

for (i = 0; i < (words_in_mem + 5); i++) {

dp = lex[i] % combined; cout << "For lex[" << i << "] the dot product was " << dp << "."; if (i <= words_in_mem)

cout << "It should have matched." << endl;

else

cout << "It should not have matched." << endl;

}

}

}