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calc/matfunc.c
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C

/*
* matfunc - extended precision rational arithmetic matrix functions
*
* Copyright (C) 1999-2007,2021-2023 David I. Bell
*
* Calc is open software; you can redistribute it and/or modify it under
* the terms of the version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* Calc is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
* Public License for more details.
*
* A copy of version 2.1 of the GNU Lesser General Public License is
* distributed with calc under the filename COPYING-LGPL. You should have
* received a copy with calc; if not, write to Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Under source code control: 1990/02/15 01:48:18
* File existed as early as: before 1990
*
* Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
*/
/*
* Extended precision rational arithmetic matrix functions.
* Matrices can contain arbitrary types of elements.
*/
#include "alloc.h"
#include "value.h"
#include "zrand.h"
#include "have_unused.h"
#include "errtbl.h"
#include "banned.h" /* include after system header <> includes */
E_FUNC long irand(long s);
S_FUNC void matswaprow(MATRIX *m, long r1, long r2);
S_FUNC void matsubrow(MATRIX *m, long oprow, long baserow, VALUE *mulval);
S_FUNC void matmulrow(MATRIX *m, long row, VALUE *mulval);
S_FUNC MATRIX *matident(MATRIX *m);
/*
* Add two compatible matrices.
*/
MATRIX *
matadd(MATRIX *m1, MATRIX *m2)
{
int dim;
long min1, min2, max1, max2, index;
VALUE *v1, *v2, *vres;
MATRIX *res;
MATRIX tmp;
if (m1->m_dim != m2->m_dim) {
math_error("Incompatible matrix dimensions for add");
not_reached();
}
tmp.m_dim = m1->m_dim;
tmp.m_size = m1->m_size;
for (dim = 0; dim < m1->m_dim; dim++) {
min1 = m1->m_min[dim];
max1 = m1->m_max[dim];
min2 = m2->m_min[dim];
max2 = m2->m_max[dim];
if ((min1 && min2 && (min1 != min2)) ||
((max1-min1) != (max2-min2))) {
math_error("Incompatible matrix bounds for add");
not_reached();
}
tmp.m_min[dim] = (min1 ? min1 : min2);
tmp.m_max[dim] = tmp.m_min[dim] + (max1 - min1);
}
res = matalloc(m1->m_size);
*res = tmp;
v1 = m1->m_table;
v2 = m2->m_table;
vres = res->m_table;
for (index = m1->m_size; index > 0; index--)
addvalue(v1++, v2++, vres++);
return res;
}
/*
* Subtract two compatible matrices.
*/
MATRIX *
matsub(MATRIX *m1, MATRIX *m2)
{
int dim;
long min1, min2, max1, max2, index;
VALUE *v1, *v2, *vres;
MATRIX *res;
MATRIX tmp;
if (m1->m_dim != m2->m_dim) {
math_error("Incompatible matrix dimensions for sub");
not_reached();
}
tmp.m_dim = m1->m_dim;
tmp.m_size = m1->m_size;
for (dim = 0; dim < m1->m_dim; dim++) {
min1 = m1->m_min[dim];
max1 = m1->m_max[dim];
min2 = m2->m_min[dim];
max2 = m2->m_max[dim];
if ((min1 && min2 && (min1 != min2)) ||
((max1-min1) != (max2-min2))) {
math_error("Incompatible matrix bounds for sub");
not_reached();
}
tmp.m_min[dim] = (min1 ? min1 : min2);
tmp.m_max[dim] = tmp.m_min[dim] + (max1 - min1);
}
res = matalloc(m1->m_size);
*res = tmp;
v1 = m1->m_table;
v2 = m2->m_table;
vres = res->m_table;
for (index = m1->m_size; index > 0; index--)
subvalue(v1++, v2++, vres++);
return res;
}
/*
* Produce the negative of a matrix.
*/
MATRIX *
matneg(MATRIX *m)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
negvalue(val++, vres++);
return res;
}
/*
* Multiply two compatible matrices.
*/
MATRIX *
matmul(MATRIX *m1, MATRIX *m2)
{
register MATRIX *res;
long i1, i2, max1, max2, index, maxindex;
VALUE *v1, *v2, *vres;
VALUE sum, tmp1, tmp2;
if (m1->m_dim == 0) {
i2 = m2->m_size;
v2 = m2->m_table;
res = matalloc(i2);
*res = *m2;
vres = res->m_table;
while (i2-- > 0)
mulvalue(m1->m_table, v2++, vres++);
return res;
}
if (m2->m_dim == 0) {
i1 = m1->m_size;
v1 = m1->m_table;
res = matalloc(i1);
*res = *m1;
vres = res->m_table;
while (i1-- > 0)
mulvalue(v1++, m2->m_table, vres++);
return res;
}
if (m1->m_dim == 1 && m2->m_dim == 1) {
if (m1->m_max[0]-m1->m_min[0] != m2->m_max[0]-m2->m_min[0]) {
math_error("Incompatible bounds for 1D * 1D matmul");
not_reached();
}
res = matalloc(m1->m_size);
*res = *m1;
v1 = m1->m_table;
v2 = m2->m_table;
vres = res->m_table;
for (index = m1->m_size; index > 0; index--)
mulvalue(v1++, v2++, vres++);
return res;
}
if (m1->m_dim == 1 && m2->m_dim == 2) {
if (m1->m_max[0]-m1->m_min[0] != m2->m_max[0]-m2->m_min[0]) {
math_error("Incompatible bounds for 1D * 2D matmul");
not_reached();
}
res = matalloc(m2->m_size);
*res = *m2;
i1 = m1->m_max[0] - m1->m_min[0] + 1;
max2 = m2->m_max[1] - m2->m_min[1] + 1;
v1 = m1->m_table;
v2 = m2->m_table;
vres = res->m_table;
while (i1-- > 0) {
i2 = max2;
while (i2-- > 0)
mulvalue(v1, v2++, vres++);
v1++;
}
return res;
}
if (m1->m_dim == 2 && m2->m_dim == 1) {
if (m1->m_max[1]-m1->m_min[1] != m2->m_max[0]-m2->m_min[0]) {
math_error("Incompatible bounds for 2D * 1D matmul");
not_reached();
}
res = matalloc(m1->m_size);
*res = *m1;
i1 = m1->m_max[0] - m1->m_min[0] + 1;
max1 = m1->m_max[1] - m1->m_min[1] + 1;
v1 = m1->m_table;
vres = res->m_table;
while (i1-- > 0) {
v2 = m2->m_table;
i2 = max1;
while (i2-- > 0)
mulvalue(v1++, v2++, vres++);
}
return res;
}
if ((m1->m_dim != 2) || (m2->m_dim != 2)) {
math_error("Matrix dimensions not compatible for mul");
not_reached();
}
if ((m1->m_max[1]-m1->m_min[1]) != (m2->m_max[0]-m2->m_min[0])) {
math_error("Incompatible bounds for 2D * 2D matrix mul");
not_reached();
}
max1 = (m1->m_max[0] - m1->m_min[0] + 1);
max2 = (m2->m_max[1] - m2->m_min[1] + 1);
maxindex = (m1->m_max[1] - m1->m_min[1] + 1);
res = matalloc(max1 * max2);
res->m_dim = 2;
res->m_min[0] = m1->m_min[0];
res->m_max[0] = m1->m_max[0];
res->m_min[1] = m2->m_min[1];
res->m_max[1] = m2->m_max[1];
for (i1 = 0; i1 < max1; i1++) {
for (i2 = 0; i2 < max2; i2++) {
sum.v_type = V_NULL;
sum.v_subtype = V_NOSUBTYPE;
v1 = &m1->m_table[i1 * maxindex];
v2 = &m2->m_table[i2];
for (index = 0; index < maxindex; index++) {
mulvalue(v1, v2, &tmp1);
addvalue(&sum, &tmp1, &tmp2);
freevalue(&tmp1);
freevalue(&sum);
sum = tmp2;
v1++;
if (index+1 < maxindex)
v2 += max2;
}
index = (i1 * max2) + i2;
res->m_table[index] = sum;
}
}
return res;
}
/*
* Square a matrix.
*/
MATRIX *
matsquare(MATRIX *m)
{
register MATRIX *res;
long i1, i2, max, index;
VALUE *v1, *v2;
VALUE sum, tmp1, tmp2;
if (m->m_dim < 2) {
res = matalloc(m->m_size);
*res = *m;
v1 = m->m_table;
v2 = res->m_table;
for (index = m->m_size; index > 0; index--)
squarevalue(v1++, v2++);
return res;
}
if (m->m_dim != 2) {
math_error("Matrix dimension exceeds two for square");
not_reached();
}
if ((m->m_max[0] - m->m_min[0]) != (m->m_max[1] - m->m_min[1])) {
math_error("Squaring non-square matrix");
not_reached();
}
max = (m->m_max[0] - m->m_min[0] + 1);
res = matalloc(max * max);
res->m_dim = 2;
res->m_min[0] = m->m_min[0];
res->m_max[0] = m->m_max[0];
res->m_min[1] = m->m_min[1];
res->m_max[1] = m->m_max[1];
for (i1 = 0; i1 < max; i1++) {
for (i2 = 0; i2 < max; i2++) {
sum.v_type = V_NULL;
sum.v_subtype = V_NOSUBTYPE;
v1 = &m->m_table[i1 * max];
v2 = &m->m_table[i2];
for (index = 0; index < max; index++) {
mulvalue(v1, v2, &tmp1);
addvalue(&sum, &tmp1, &tmp2);
freevalue(&tmp1);
freevalue(&sum);
sum = tmp2;
v1++;
v2 += max;
}
index = (i1 * max) + i2;
res->m_table[index] = sum;
}
}
return res;
}
/*
* Compute the result of raising a matrix to an integer power if
* dimension <= 2 and for dimension == 2, the matrix is square.
* Negative powers mean the positive power of the inverse.
* Note: This calculation could someday be improved for large powers
* by using the characteristic polynomial of the matrix.
*
* given:
* m matrix to be raised
* q power to raise it to
*/
MATRIX *
matpowi(MATRIX *m, NUMBER *q)
{
MATRIX *res, *tmp;
long power; /* power to raise to */
FULL bit; /* current bit value */
if (m->m_dim > 2) {
math_error("Matrix dimension greater than 2 for power");
not_reached();
}
if (m->m_dim == 2 && (m->m_max[0] - m->m_min[0] !=
m->m_max[1] - m->m_min[1])) {
math_error("Raising non-square 2D matrix to a power");
not_reached();
}
if (qisfrac(q)) {
math_error("Raising matrix to non-integral power");
not_reached();
}
if (zge31b(q->num)) {
math_error("Raising matrix to very large power");
not_reached();
}
power = ztolong(q->num);
if (qisneg(q))
power = -power;
/*
* Handle some low powers specially
*/
if ((power <= 4) && (power >= -2)) {
switch ((int) power) {
case 0:
return matident(m);
case 1:
return matcopy(m);
case -1:
return matinv(m);
case 2:
return matsquare(m);
case -2:
tmp = matinv(m);
res = matsquare(tmp);
matfree(tmp);
return res;
case 3:
tmp = matsquare(m);
res = matmul(m, tmp);
matfree(tmp);
return res;
case 4:
tmp = matsquare(m);
res = matsquare(tmp);
matfree(tmp);
return res;
}
}
if (power < 0) {
m = matinv(m);
power = -power;
}
/*
* Compute the power by squaring and multiplying.
* This uses the left to right method of power raising.
*/
bit = TOPFULL;
while ((bit & power) == 0)
bit >>= 1L;
bit >>= 1L;
res = matsquare(m);
if (bit & power) {
tmp = matmul(res, m);
matfree(res);
res = tmp;
}
bit >>= 1L;
while (bit) {
tmp = matsquare(res);
matfree(res);
res = tmp;
if (bit & power) {
tmp = matmul(res, m);
matfree(res);
res = tmp;
}
bit >>= 1L;
}
if (qisneg(q))
matfree(m);
return res;
}
/*
* Calculate the cross product of two one dimensional matrices each
* with three components.
* m3 = matcross(m1, m2);
*/
MATRIX *
matcross(MATRIX *m1, MATRIX *m2)
{
MATRIX *res;
VALUE *v1, *v2, *vr;
VALUE tmp1, tmp2;
res = matalloc(3L);
res->m_dim = 1;
res->m_min[0] = 0;
res->m_max[0] = 2;
v1 = m1->m_table;
v2 = m2->m_table;
vr = res->m_table;
mulvalue(v1 + 1, v2 + 2, &tmp1);
mulvalue(v1 + 2, v2 + 1, &tmp2);
subvalue(&tmp1, &tmp2, vr + 0);
freevalue(&tmp1);
freevalue(&tmp2);
mulvalue(v1 + 2, v2 + 0, &tmp1);
mulvalue(v1 + 0, v2 + 2, &tmp2);
subvalue(&tmp1, &tmp2, vr + 1);
freevalue(&tmp1);
freevalue(&tmp2);
mulvalue(v1 + 0, v2 + 1, &tmp1);
mulvalue(v1 + 1, v2 + 0, &tmp2);
subvalue(&tmp1, &tmp2, vr + 2);
freevalue(&tmp1);
freevalue(&tmp2);
return res;
}
/*
* Return the dot product of two matrices.
* result = matdot(m1, m2);
*/
VALUE
matdot(MATRIX *m1, MATRIX *m2)
{
VALUE *v1, *v2;
VALUE result, tmp1, tmp2;
long len;
v1 = m1->m_table;
v2 = m2->m_table;
mulvalue(v1, v2, &result);
len = m1->m_size;
while (--len > 0) {
mulvalue(++v1, ++v2, &tmp1);
addvalue(&result, &tmp1, &tmp2);
freevalue(&tmp1);
freevalue(&result);
result = tmp2;
}
return result;
}
/*
* Scale the elements of a matrix by a specified power of two.
*
* given:
* m matrix to be scaled
* n scale factor
*/
MATRIX *
matscale(MATRIX *m, long n)
{
register VALUE *val, *vres;
VALUE temp;
long index;
MATRIX *res; /* resulting matrix */
if (n == 0)
return matcopy(m);
temp.v_type = V_NUM;
temp.v_subtype = V_NOSUBTYPE;
temp.v_num = itoq(n);
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
scalevalue(val++, &temp, vres++);
qfree(temp.v_num);
return res;
}
/*
* Shift the elements of a matrix by the specified number of bits.
* Positive shift means leftwards, negative shift rightwards.
*
* given:
* m matrix to be shifted
* n shift count
*/
MATRIX *
matshift(MATRIX *m, long n)
{
register VALUE *val, *vres;
VALUE temp;
long index;
MATRIX *res; /* resulting matrix */
if (n == 0)
return matcopy(m);
temp.v_type = V_NUM;
temp.v_subtype = V_NOSUBTYPE;
temp.v_num = itoq(n);
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
shiftvalue(val++, &temp, false, vres++);
qfree(temp.v_num);
return res;
}
/*
* Multiply the elements of a matrix by a specified value.
*
* given:
* m matrix to be multiplied
* vp value to multiply by
*/
MATRIX *
matmulval(MATRIX *m, VALUE *vp)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
mulvalue(val++, vp, vres++);
return res;
}
/*
* Divide the elements of a matrix by a specified value, keeping
* only the integer quotient.
*
* given:
* m matrix to be divided
* vp value to divide by
* v3 rounding type parameter
*/
MATRIX *
matquoval(MATRIX *m, VALUE *vp, VALUE *v3)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
if ((vp->v_type == V_NUM) && qiszero(vp->v_num)) {
math_error("Division by zero");
not_reached();
}
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
quovalue(val++, vp, v3, vres++);
return res;
}
/*
* Divide the elements of a matrix by a specified value, keeping
* only the remainder of the division.
*
* given:
* m matrix to be divided
* vp value to divide by
* v3 rounding type parameter
*/
MATRIX *
matmodval(MATRIX *m, VALUE *vp, VALUE *v3)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
if ((vp->v_type == V_NUM) && qiszero(vp->v_num)) {
math_error("Division by zero");
not_reached();
}
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
modvalue(val++, vp, v3, vres++);
return res;
}
VALUE
mattrace(MATRIX *m)
{
VALUE *vp;
VALUE sum;
VALUE tmp;
long i, j;
if (m->m_dim < 2) {
matsum(m, &sum);
return sum;
}
if (m->m_dim != 2)
return error_value(E_MATTRACE_2);
i = (m->m_max[0] - m->m_min[0] + 1);
j = (m->m_max[1] - m->m_min[1] + 1);
if (i != j)
return error_value(E_MATTRACE_3);
vp = m->m_table;
copyvalue(vp, &sum);
j++;
while (--i > 0) {
vp += j;
addvalue(&sum, vp, &tmp);
freevalue(&sum);
sum = tmp;
}
return sum;
}
/*
* Transpose a 2-dimensional matrix
*/
MATRIX *
mattrans(MATRIX *m)
{
register VALUE *v1, *v2; /* current values */
long rows, cols; /* rows and columns in new matrix */
long row, col; /* current row and column */
MATRIX *res;
if (m->m_dim < 2)
return matcopy(m);
res = matalloc(m->m_size);
res->m_dim = 2;
res->m_min[0] = m->m_min[1];
res->m_max[0] = m->m_max[1];
res->m_min[1] = m->m_min[0];
res->m_max[1] = m->m_max[0];
rows = (m->m_max[1] - m->m_min[1] + 1);
cols = (m->m_max[0] - m->m_min[0] + 1);
v1 = res->m_table;
for (row = 0; row < rows; row++) {
v2 = &m->m_table[row];
for (col = 0; col < cols; col++) {
copyvalue(v2, v1);
v1++;
v2 += rows;
}
}
return res;
}
/*
* Produce a matrix with values all of which are conjugated.
*/
MATRIX *
matconj(MATRIX *m)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
conjvalue(val++, vres++);
return res;
}
/*
* Round elements of a matrix to specified number of decimal digits
*/
MATRIX *
matround(MATRIX *m, VALUE *v2, VALUE *v3)
{
VALUE *p, *q;
long s;
MATRIX *res;
s = m->m_size;
res = matalloc(s);
*res = *m;
p = m->m_table;
q = res->m_table;
while (s-- > 0)
roundvalue(p++, v2, v3, q++);
return res;
}
/*
* Round elements of a matrix to specified number of binary digits
*/
MATRIX *
matbround(MATRIX *m, VALUE *v2, VALUE *v3)
{
VALUE *p, *q;
long s;
MATRIX *res;
s = m->m_size;
res = matalloc(s);
*res = *m;
p = m->m_table;
q = res->m_table;
while (s-- > 0)
broundvalue(p++, v2, v3, q++);
return res;
}
/*
* Approximate a matrix by approximating elements to be multiples of
* v2, rounding type determined by v3.
*/
MATRIX *
matappr(MATRIX *m, VALUE *v2, VALUE *v3)
{
VALUE *p, *q;
long s;
MATRIX *res;
s = m->m_size;
res = matalloc(s);
*res = *m;
p = m->m_table;
q = res->m_table;
while (s-- > 0)
apprvalue(p++, v2, v3, q++);
return res;
}
/*
* Produce a matrix with values all of which have been truncated to integers.
*/
MATRIX *
matint(MATRIX *m)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
intvalue(val++, vres++);
return res;
}
/*
* Produce a matrix with values all of which have only the fraction part left.
*/
MATRIX *
matfrac(MATRIX *m)
{
register VALUE *val, *vres;
long index;
MATRIX *res;
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (index = m->m_size; index > 0; index--)
fracvalue(val++, vres++);
return res;
}
/*
* Index a matrix normally by the specified set of index values.
* Returns the address of the matrix element if it is valid, or generates
* an error if the index values are out of range. The create flag is true
* if the element is to be written, but this is ignored here.
*
* given:
* mp matrix to operate on
* create true => create if element does not exist
* dim dimension of the indexing
* indices table of values being indexed by
*/
/*ARGSUSED*/
VALUE *
matindex(MATRIX *mp, bool UNUSED(create), long dim, VALUE *indices)
{
NUMBER *q; /* index value */
VALUE *vp;
long index; /* index value as an integer */
long offset; /* current offset into array */
int i; /* loop counter */
if (dim < 0) {
math_error("Negative dimension %ld for matrix", dim);
not_reached();
}
for (;;) {
if (dim < mp->m_dim) {
math_error(
"Indexing a %ldd matrix as a %ldd matrix",
mp->m_dim, dim);
not_reached();
}
offset = 0;
for (i = 0; i < mp->m_dim; i++) {
if (indices->v_type != V_NUM) {
math_error("Non-numeric index for matrix");
not_reached();
}
q = indices->v_num;
if (qisfrac(q)) {
math_error("Non-integral index for matrix");
not_reached();
}
index = qtoi(q);
if (zge31b(q->num) || (index < mp->m_min[i]) ||
(index > mp->m_max[i])) {
math_error("Index out of bounds for matrix");
not_reached();
}
offset *= (mp->m_max[i] - mp->m_min[i] + 1);
offset += (index - mp->m_min[i]);
indices++;
}
vp = mp->m_table + offset;
dim -= mp->m_dim;
if (dim == 0)
break;
if (vp->v_type != V_MAT) {
math_error("Non-matrix argument for matindex");
not_reached();
}
mp = vp->v_mat;
}
return vp;
}
/*
* Returns the list of indices for a matrix element with specified
* double-bracket index.
*/
LIST *
matindices(MATRIX *mp, long index)
{
LIST *lp;
int j;
long d;
VALUE val;
if (index < 0 || index >= mp->m_size)
return NULL;
lp = listalloc();
val.v_type = V_NUM;
val.v_subtype = V_NOSUBTYPE;
j = mp->m_dim;
while (--j >= 0) {
d = mp->m_max[j] - mp->m_min[j] + 1;
val.v_num = itoq(index % d + mp->m_min[j]);
insertlistfirst(lp, &val);
qfree(val.v_num);
index /= d;
}
return lp;
}
/*
* Search a matrix for the specified value, starting with the specified index.
* Returns 0 and stores index if value found; otherwise returns 1.
*/
int
matsearch(MATRIX *m, VALUE *vp, long i, long j, ZVALUE *index)
{
register VALUE *val;
val = &m->m_table[i];
if (i < 0 || j > m->m_size) {
math_error("This should not happen in call to matsearch");
not_reached();
}
while (i < j) {
if (acceptvalue(val++, vp)) {
utoz(i, index);
return 0;
}
i++;
}
return 1;
}
/*
* Search a matrix backwards for the specified value, starting with the
* specified index. Returns 0 and stores index if value found; otherwise
* returns 1.
*/
int
matrsearch(MATRIX *m, VALUE *vp, long i, long j, ZVALUE *index)
{
register VALUE *val;
if (i < 0 || j > m->m_size) {
math_error("This should not happen in call to matrsearch");
not_reached();
}
val = &m->m_table[--j];
while (j >= i) {
if (acceptvalue(val--, vp)) {
utoz(j, index);
return 0;
}
j--;
}
return 1;
}
/*
* Fill all of the elements of a matrix with one of two specified values.
* All entries are filled with the first specified value, except that if
* the matrix is w-dimensional and the second value pointer is non-NULL, then
* all diagonal entries are filled with the second value. This routine
* affects the supplied matrix directly, and doesn't return a copy.
*
* given:
* m matrix to be filled
* v1 value to fill most of matrix with
* v2 value for diagonal entries or null
*/
void
matfill(MATRIX *m, VALUE *v1, VALUE *v2)
{
register VALUE *val;
VALUE temp1, temp2;
long rows, cols;
long i, j;
copyvalue(v1, &temp1);
val = m->m_table;
if (m->m_dim != 2 || v2 == NULL) {
for (i = m->m_size; i > 0; i--) {
freevalue(val);
copyvalue(&temp1, val++);
}
freevalue(&temp1);
return;
}
copyvalue(v2, &temp2);
rows = m->m_max[0] - m->m_min[0] + 1;
cols = m->m_max[1] - m->m_min[1] + 1;
for (i = 0; i < rows; i++) {
for (j = 0; j < cols; j++) {
freevalue(val);
if (i == j)
copyvalue(&temp2, val++);
else
copyvalue(&temp1, val++);
}
}
freevalue(&temp1);
freevalue(&temp2);
}
/*
* Set a copy of a square matrix to the identity matrix.
*/
S_FUNC MATRIX *
matident(MATRIX *m)
{
register VALUE *val; /* current value */
long row, col; /* current row and column */
long rows; /* number of rows */
MATRIX *res; /* resulting matrix */
if (m->m_dim != 2) {
math_error(
"Matrix dimension must be two for setting to identity");
not_reached();
}
if ((m->m_max[0] - m->m_min[0]) != (m->m_max[1] - m->m_min[1])) {
math_error("Matrix must be square for setting to identity");
not_reached();
}
res = matalloc(m->m_size);
*res = *m;
val = res->m_table;
rows = (res->m_max[0] - res->m_min[0] + 1);
for (row = 0; row < rows; row++) {
for (col = 0; col < rows; col++) {
val->v_type = V_NUM;
val->v_subtype = V_NOSUBTYPE;
val->v_num = ((row == col) ? qlink(&_qone_) :
qlink(&_qzero_));
val++;
}
}
return res;
}
/*
* Calculate the inverse of a matrix if it exists.
* This is done by using transformations on the supplied matrix to convert
* it to the identity matrix, and simultaneously applying the same set of
* transformations to the identity matrix.
*/
MATRIX *
matinv(MATRIX *m)
{
MATRIX *res; /* matrix to become the inverse */
long rows; /* number of rows */
long cur; /* current row being worked on */
long row, col; /* temp row and column values */
VALUE *val; /* current value in matrix*/
VALUE *vres; /* current value in result for dim < 2 */
VALUE mulval; /* value to multiply rows by */
VALUE tmpval; /* temporary value */
if (m->m_dim < 2) {
res = matalloc(m->m_size);
*res = *m;
val = m->m_table;
vres = res->m_table;
for (cur = m->m_size; cur > 0; cur--)
invertvalue(val++, vres++);
return res;
}
if (m->m_dim != 2) {
math_error("Matrix dimension exceeds two for inverse");
not_reached();
}
if ((m->m_max[0] - m->m_min[0]) != (m->m_max[1] - m->m_min[1])) {
math_error("Inverting non-square matrix");
not_reached();
}
/*
* Begin by creating the identity matrix with the same attributes.
*/
res = matalloc(m->m_size);
*res = *m;
rows = (m->m_max[0] - m->m_min[0] + 1);
val = res->m_table;
for (row = 0; row < rows; row++) {
for (col = 0; col < rows; col++) {
if (row == col)
val->v_num = qlink(&_qone_);
else
val->v_num = qlink(&_qzero_);
val->v_type = V_NUM;
val->v_subtype = V_NOSUBTYPE;
val++;
}
}
/*
* Now loop over each row, and eliminate all entries in the
* corresponding column by using row operations. Do the same
* operations on the resulting matrix. Copy the original matrix
* so that we don't destroy it.
*/
m = matcopy(m);
for (cur = 0; cur < rows; cur++) {
/*
* Find the first nonzero value in the rest of the column
* downwards from [cur,cur]. If there is no such value, then
* the matrix is not invertible. If the first nonzero entry
* is not the current row, then swap the two rows to make the
* current one nonzero.
*/
row = cur;
val = &m->m_table[(row * rows) + row];
while (testvalue(val) == 0) {
if (++row >= rows) {
matfree(m);
matfree(res);
math_error("Matrix is not invertible");
not_reached();
}
val += rows;
}
invertvalue(val, &mulval);
if (row != cur) {
matswaprow(m, row, cur);
matswaprow(res, row, cur);
}
/*
* Now for every other nonzero entry in the current column,
* subtract the appropriate multiple of the current row to
* force that entry to become zero.
*/
val = &m->m_table[cur];
for (row = 0; row < rows; row++) {
if ((row == cur) || (testvalue(val) == 0)) {
if (row+1 < rows)
val += rows;
continue;
}
mulvalue(val, &mulval, &tmpval);
matsubrow(m, row, cur, &tmpval);
matsubrow(res, row, cur, &tmpval);
freevalue(&tmpval);
if (row+1 < rows)
val += rows;
}
freevalue(&mulval);
}
/*
* Now the original matrix has nonzero entries only on its main
* diagonal. Scale the rows of the result matrix by the inverse
* of those entries.
*/
val = m->m_table;
for (row = 0; row < rows; row++) {
if ((val->v_type != V_NUM) || !qisone(val->v_num)) {
invertvalue(val, &mulval);
matmulrow(res, row, &mulval);
freevalue(&mulval);
}
if (row+1 < rows)
val += (rows + 1);
}
matfree(m);
return res;
}
/*
* Calculate the determinant of a square matrix.
* This uses the fraction-free Gauss-Bareiss algorithm.
*/
VALUE
matdet(MATRIX *m)
{
long n; /* original matrix is n x n */
long k; /* working sub-matrix is k x k */
long i, j;
VALUE *pivot, *div, *val;
VALUE *vp, *vv;
VALUE tmp1, tmp2, tmp3;
bool neg; /* whether to negate determinant */
if (m->m_dim < 2) {
vp = m->m_table;
i = m->m_size;
copyvalue(vp, &tmp1);
while (--i > 0) {
mulvalue(&tmp1, ++vp, &tmp2);
freevalue(&tmp1);
tmp1 = tmp2;
}
return tmp1;
}
if (m->m_dim != 2)
return error_value(E_DET_2);
if ((m->m_max[0] - m->m_min[0]) != (m->m_max[1] - m->m_min[1]))
return error_value(E_DET_3);
/*
* Loop over each row, and eliminate all lower entries in the
* corresponding column by using row operations. Copy the original
* matrix so that we don't destroy it.
*/
neg = false;
m = matcopy(m);
n = (m->m_max[0] - m->m_min[0] + 1);
pivot = div = m->m_table;
for (k = n; k > 0; k--) {
/*
* Find the first nonzero value in the rest of the column
* downwards from pivot. If there is no such value, then
* the determinant is zero. If the first nonzero entry is not
* the pivot, then swap rows in the k * k sub-matrix, and
* remember that the determinant changes sign.
*/
val = pivot;
i = k;
while (!testvalue(val)) {
if (--i <= 0) {
tmp1.v_type = V_NUM;
tmp1.v_subtype = V_NOSUBTYPE;
tmp1.v_num = qlink(&_qzero_);
matfree(m);
return tmp1;
}
val += n;
}
if (i < k) {
vp = pivot;
vv = val;
j = k;
while (j-- > 0) {
tmp1 = *vp;
*vp++ = *vv;
*vv++ = tmp1;
}
neg = !neg;
}
/*
* Now for every val below the pivot, for each entry to
* the right of val, calculate the 2 x 2 determinant
* with corners at the pivot and the entry. If
* k < n, divide by div (the previous pivot value).
*/
val = pivot;
i = k;
while (--i > 0) {
val += n;
vp = pivot;
vv = val;
j = k;
while (--j > 0) {
mulvalue(pivot, ++vv, &tmp1);
mulvalue(val, ++vp, &tmp2);
subvalue(&tmp1, &tmp2, &tmp3);
freevalue(&tmp1);
freevalue(&tmp2);
freevalue(vv);
if (k < n) {
divvalue(&tmp3, div, vv);
freevalue(&tmp3);
}
else
*vv = tmp3;
}
}
div = pivot;
if (k > 0)
pivot += n + 1;
}
if (neg)
negvalue(div, &tmp1);
else
copyvalue(div, &tmp1);
matfree(m);
return tmp1;
}
/*
* Local utility routine to swap two rows of a square matrix.
* No checks are made to verify the legality of the arguments.
*/
S_FUNC void
matswaprow(MATRIX *m, long r1, long r2)
{
register VALUE *v1, *v2;
register long rows;
VALUE tmp;
if (r1 == r2)
return;
rows = (m->m_max[0] - m->m_min[0] + 1);
v1 = &m->m_table[r1 * rows];
v2 = &m->m_table[r2 * rows];
while (rows-- > 0) {
tmp = *v1;
*v1 = *v2;
*v2 = tmp;
v1++;
v2++;
}
}
/*
* Local utility routine to subtract a multiple of one row to another one.
* The row to be changed is oprow, the row to be subtracted is baserow.
* No checks are made to verify the legality of the arguments.
*/
S_FUNC void
matsubrow(MATRIX *m, long oprow, long baserow, VALUE *mulval)
{
register VALUE *vop, *vbase;
register long entries;
VALUE tmp1, tmp2;
entries = (m->m_max[0] - m->m_min[0] + 1);
vop = &m->m_table[oprow * entries];
vbase = &m->m_table[baserow * entries];
while (entries-- > 0) {
mulvalue(vbase, mulval, &tmp1);
subvalue(vop, &tmp1, &tmp2);
freevalue(&tmp1);
freevalue(vop);
*vop = tmp2;
vop++;
vbase++;
}
}
/*
* Local utility routine to multiply a row by a specified number.
* No checks are made to verify the legality of the arguments.
*/
S_FUNC void
matmulrow(MATRIX *m, long row, VALUE *mulval)
{
register VALUE *val;
register long rows;
VALUE tmp;
rows = (m->m_max[0] - m->m_min[0] + 1);
val = &m->m_table[row * rows];
while (rows-- > 0) {
mulvalue(val, mulval, &tmp);
freevalue(val);
*val = tmp;
val++;
}
}
/*
* Make a full copy of a matrix.
*/
MATRIX *
matcopy(MATRIX *m)
{
MATRIX *res;
register VALUE *v1, *v2;
register long i;
res = matalloc(m->m_size);
*res = *m;
v1 = m->m_table;
v2 = res->m_table;
i = m->m_size;
while (i-- > 0) {
copyvalue(v1, v2);
v1++;
v2++;
}
return res;
}
/*
* Make a matrix the same size as another and filled with a fixed value.
*
* given:
* m matrix to initialize
* v1 value to fill most of matrix with
* v2 value for diagonal entries (or NULL)
*/
MATRIX *
matinit(MATRIX *m, VALUE *v1, VALUE *v2)
{
MATRIX *res;
register VALUE *v;
register long i;
long row;
long rows;
/*
* clone matrix size
*/
res = matalloc(m->m_size);
*res = *m;
/*
* firewall
*/
if (v2 && ((res->m_dim != 2) ||
((res->m_max[0] - res->m_min[0]) !=
(res->m_max[1] - res->m_min[1])))) {
math_error("Filling diagonals of non-square matrix");
not_reached();
}
/*
* fill the bulk of the matrix
*/
v = res->m_table;
if (v2 == NULL) {
i = m->m_size;
while (i-- > 0) {
copyvalue(v1, v++);
}
return res;
}
/*
* fill the diagonal of a square matrix if requested
*/
rows = res->m_max[0] - res->m_min[0] + 1;
v = res->m_table;
for (row = 0; row < rows; row++) {
copyvalue(v2, v+row);
v += rows;
}
return res;
}
/*
* Allocate a matrix with the specified number of elements.
*/
MATRIX *
matalloc(long size)
{
MATRIX *m;
long i;
VALUE *vp;
m = (MATRIX *) malloc(matsize(size));
if (m == NULL) {
math_error("Cannot get memory to allocate matrix of size %ld",
size);
not_reached();
}
m->m_size = size;
for (i = size, vp = m->m_table; i > 0; i--, vp++)
vp->v_subtype = V_NOSUBTYPE;
return m;
}
/*
* Free a matrix, along with all of its element values.
*/
void
matfree(MATRIX *m)
{
register VALUE *vp;
register long i;
vp = m->m_table;
i = m->m_size;
while (i-- > 0)
freevalue(vp++);
free(m);
}
/*
* Test whether a matrix has any "nonzero" values.
* Returns true if so.
*/
bool
mattest(MATRIX *m)
{
register VALUE *vp;
register long i;
vp = m->m_table;
i = m->m_size;
while (i-- > 0) {
if (testvalue(vp++))
return true;
}
return false;
}
/*
* Sum the elements in a matrix.
*/
void
matsum(MATRIX *m, VALUE *vres)
{
VALUE *vp;
VALUE tmp; /* first sum value */
VALUE sum; /* final sum value */
long i;
vp = m->m_table;
i = m->m_size;
copyvalue(vp, &sum);
while (--i > 0) {
addvalue(&sum, ++vp, &tmp);
freevalue(&sum);
sum = tmp;
}
*vres = sum;
}
/*
* Test whether or not two matrices are equal.
* Equality is determined by the shape and values of the matrices,
* but not by their index bounds. Returns true if they differ.
*/
bool
matcmp(MATRIX *m1, MATRIX *m2)
{
VALUE *v1, *v2;
long i;
if (m1 == m2)
return false;
if ((m1->m_dim != m2->m_dim) || (m1->m_size != m2->m_size))
return true;
for (i = 0; i < m1->m_dim; i++) {
if ((m1->m_max[i] - m1->m_min[i]) !=
(m2->m_max[i] - m2->m_min[i]))
return true;
}
v1 = m1->m_table;
v2 = m2->m_table;
i = m1->m_size;
while (i-- > 0) {
if (comparevalue(v1++, v2++))
return true;
}
return false;
}
void
matreverse(MATRIX *m)
{
VALUE *p, *q;
VALUE tmp;
p = m->m_table;
q = m->m_table + m->m_size - 1;
while (q > p) {
tmp = *p;
*p++ = *q;
*q-- = tmp;
}
}
void
matsort(MATRIX *m)
{
VALUE *a, *b, *next, *end;
VALUE *buf, *p;
VALUE *S[LONG_BITS];
long len[LONG_BITS];
long i, j, k;
buf = (VALUE *) malloc(m->m_size * sizeof(VALUE));
if (buf == NULL) {
math_error("Not enough memory for matsort");
not_reached();
}
next = m->m_table;
end = next + m->m_size;
for (k = 0; next && k < LONG_BITS; k++) {
S[k] = next++; /* S[k] is start of a run */
len[k] = 1;
if (next == end)
next = NULL;
while (k > 0 && (!next || len[k] >= len[k - 1])) {/* merging */
j = len[k];
b = S[k--];
i = len[k];
a = S[k];
len[k] += j;
p = buf;
if (precvalue(b, a)) {
do {
*p++ = *b++;
j--;
} while (j > 0 && precvalue(b,a));
if (j == 0) {
memcpy(p, a, i * sizeof(VALUE));
memcpy(S[k], buf,
len[k] * sizeof(VALUE));
continue;
}
}
do {
do {
*p++ = *a++;
i--;
} while (i > 0 && !precvalue(b,a));
if (i == 0) {
break;
}
do {
*p++ = *b++;
j--;
} while (j > 0 && precvalue(b,a));
} while (j != 0);
if (i == 0) {
memcpy(S[k], buf, (p - buf) * sizeof(VALUE));
} else if (j == 0) {
memcpy(p, a, i * sizeof(VALUE));
memcpy(S[k], buf, len[k] * sizeof(VALUE));
}
}
}
free(buf);
if (k >= LONG_BITS) {
/* this should never happen */
math_error("impossible k overflow in matsort!");
not_reached();
}
}
void
matrandperm(MATRIX *m)
{
VALUE *vp;
long s, i;
VALUE val;
s = m->m_size;
for (vp = m->m_table; s > 1; vp++, s--) {
i = irand(s);
if (i > 0) {
val = *vp;
*vp = vp[i];
vp[i] = val;
}
}
}
/*
* Test whether or not a matrix is the identity matrix.
* Returns true if so.
*/
bool
matisident(MATRIX *m)
{
register VALUE *val; /* current value */
long row, col; /* row and column numbers */
val = m->m_table;
if (m->m_dim == 0) {
return (val->v_type == V_NUM && qisone(val->v_num));
}
if (m->m_dim == 1) {
for (row = m->m_min[0]; row <= m->m_max[0]; row++, val++) {
if (val->v_type != V_NUM || !qisone(val->v_num))
return false;
}
return true;
}
if ((m->m_dim != 2) ||
((m->m_max[0] - m->m_min[0]) != (m->m_max[1] - m->m_min[1])))
return false;
for (row = m->m_min[0]; row <= m->m_max[0]; row++) {
/*
* We could use col = m->m_min[1]; col < m->m_max[1]
* but if m->m_min[0] != m->m_min[1] this won't work.
* We know that we have a square 2-dimensional matrix
* so we will pretend that m->m_min[0] == m->m_min[1].
*/
for (col = m->m_min[0]; col <= m->m_max[0]; col++) {
if (val->v_type != V_NUM)
return false;
if (row == col) {
if (!qisone(val->v_num))
return false;
} else {
if (!qiszero(val->v_num))
return false;
}
val++;
}
}
return true;
}
/*
* Print a matrix and possibly few of its elements.
* The argument supplied specifies how many elements to allow printing.
* If any elements are printed, they are printed in short form.
*/
void
matprint(MATRIX *m, long max_print)
{
VALUE *vp;
long fullsize, count, index;
long dim, i, j;
char *msg;
long sizes[MAXDIM];
dim = m->m_dim;
fullsize = 1;
for (i = dim - 1; i >= 0; i--) {
sizes[i] = fullsize;
fullsize *= (m->m_max[i] - m->m_min[i] + 1);
}
msg = ((max_print > 0) ? "\nmat [" : "mat [");
if (dim) {
for (i = 0; i < dim; i++) {
if (m->m_min[i]) {
math_fmt("%s%ld:%ld", msg,
m->m_min[i], m->m_max[i]);
} else {
math_fmt("%s%ld", msg, m->m_max[i] + 1);
}
msg = ",";
}
} else {
math_str("mat [");
}
if (max_print > fullsize) {
max_print = fullsize;
}
vp = m->m_table;
count = 0;
for (index = 0; index < fullsize; index++) {
if ((vp->v_type != V_NUM) || !qiszero(vp->v_num))
count++;
vp++;
}
math_fmt("] (%ld element%s, %ld nonzero)",
fullsize, (fullsize == 1) ? "" : "s", count);
if (max_print <= 0)
return;
/*
* Now print the first few elements of the matrix in short
* and unambiguous format.
*/
math_str(":\n");
vp = m->m_table;
for (index = 0; index < max_print; index++) {
msg = " [";
j = index;
if (dim) {
for (i = 0; i < dim; i++) {
math_fmt("%s%ld", msg,
m->m_min[i] + (j / sizes[i]));
j %= sizes[i];
msg = ",";
}
} else {
math_str(msg);
}
math_str("] = ");
printvalue(vp++, PRINT_SHORT | PRINT_UNAMBIG);
math_str("\n");
}
if (max_print < fullsize)
math_str(" ...\n");
}