man/man1/rmtxop.1

.\" RCSid "$Id: rmtxop.1,v 1.13 2019/08/12 01:20:25 greg Exp $"
.TH RMTXOP 1 7/8/97 RADIANCE
.SH NAME
rmtxop - concatenate, add, multiply, divide, transpose, scale, and convert matrices
.SH SYNOPSIS
.B rmtxop
[
.B \-v
][
.B \-f[afdc]
][
.B \-t
][
.B "\-s sf .."
][
.B "\-c ce .."
]
.B m1
[
.B ".+*/"
]
.B ".."
.SH DESCRIPTION
.I Rmtxop
loads and concatenates or adds/multiplies/divides
together component matrix files given on the command line.
Each file must have a header containing the following variables:
.sp
.nf
NROWS={number of rows}
NCOLS={number of columns}
NCOMP={number of components}
FORMAT={ascii|float|double|32-bit_rle_rgbe|32-bit_rle_xyze}
.sp
.fi
The number of components indicates that each matrix element is actually
composed of multiple elements, most commonly an RGB triple.
This is essentially dividing the matrix into planes, where each component
participates in a separate calculation.
If an appropriate header is not present, it may be added with a call to
.I rcollate(1).
A matrix may be read from the standard input using a hyphen by itself ('-')
in the appropriate place on the command line.
.PP
Any of the matrix inputs may be read from a command
instead of a file by
using quotes and a beginning exclamation point ('!').
.PP
Two special cases are handled for component matrices that are either
XML files containing BTDF data, or Radiance picture files.
In the first case, a BSDF library is used to load and interpret the
transmission matrix.
(XML files cannot be read from the standard input or from a command.)\0
In the second case, the RGBE or XYZE values are loaded in a 3-component
matrix where the number of columns match the X-dimension of the picture, and
the number of rows match the Y-dimension.
The picture must be in standard pixel ordering, and the first row
is at the top with the first column on the left.
.PP
Before each file, the
.I \-t
and
.I \-s
or
.I \-c
options may be used to modify the matrix.
The
.I \-t
option transposes the matrix, swapping rows and columns.
The
.I \-s
option applies the given scalar factor(s) to the elements of the matrix.
If only one factor is provided,
it will be used for all components.
If multiple factors are given, their number must match the number of matrix
components.
Alternatively, the
.I \-c
option may be used to "transform" the element values, possibly changing
the number of components in the matrix.
For example, a 3-component matrix can be transformed into a single-component
matrix by using
.I \-c
with three coefficients.
A four-component matrix can be turned into a two-component matrix using 8
coefficients, where the first four coefficients will be used to compute
the first new component, and the second four coefficients
yield the second new component.
Note that the number of coefficients must be an even multiple of the number
of original components.
The
.I \-s
and
.I \-c
options are mutually exclusive, insofar as they cannot be applied together
to the same input matrix.
.PP
If present, the second and subsequent matrices on the command
line are concatenated to the result unless separated by a plus ('+'),
asterisk ('*'), or forward slash ('/') symbol,
in which case the matrix elements are added, multiplied, or divided together,
respectively.
(Note that the asterisk must be quoted or escaped in most shells.)\0
In the case of addition, the two matrices involved must have the same number
of components.
For element-wise multiplication and division, the second matrix is
permitted instead to have a single component per element, which will be
applied equally to all components of the first matrix.
If element-wise division is specified, any zero elements in the second
matrix will result in a warning and the corresponding component(s) in the
first matrix will be set to zero.
.PP
The number of components in the new matrix after applying any
.I -c
transform must agree with the prior result.
For concatenation (matrix multiplication), the number of columns
in the prior result must equal the number of rows in the new matrix, and
the result will have the number of rows of the previous and the number
of columns of the new matrix.
In the case of addition, multiplication, and division,
the number of rows and columns of the prior result and the
new matrix must match, and will not be changed by the operation.
.PP
A final transpose or scaling/transform operation may be applied to
the results by appending the
.I \-t
and
.I \-s
or
.I \-c
options after the last matrix on the command line.
.PP
Results are sent to the standard output.
By default, the values will be written in the lowest resolution format
among the inputs, but the
.I \-f
option may be used to explicitly output components
as ASCII (-fa), binary doubles (-fd), floats (-ff), or RGBE colors (-fc).
In the latter case, the actual matrix dimensions are written in the resolution
string rather than the header.
Also, matrix results written as Radiance pictures must have either one
or three components.
In the one-component case, the output is written as grayscale.
.PP
The
.I \-v
option turns on verbose reporting, which announces each operation.
.SH EXAMPLES
To concatenate two matrix files with a BTDF between them and write
the result as binary double:
.IP "" .2i
rmtxop -fd view.vmx blinds.xml exterior.dmx > dcoef.dmx
.PP
To convert a BTDF matrix into a Radiance picture:
.IP "" .2i
rmtxop -fc blinds.xml > blinds.hdr
.PP
To scale a matrix by 4 and add it to the transpose of another matrix:
.IP "" .2i
rmtxop -s 4 left.mtx + -t right.mtx > result.mtx
.PP
To send the elements of a binary matrix to 
.I rcalc(1)
for further processing:
.IP "" .2i
rmtxop -fa orig.mtx | rcollate -ho -oc 1 | rcalc [operations]
.SH NOTES
Matrix multiplication is associative but not commutative, so order
matters to the result.
.I Rmtxop
takes advantage of the associative property to evaluate the
implicit equation from right to left when this reduces the
number of basic operations.
If the rightmost matrix is a column vector for example, it is
much faster to concatenate from the right, and the result should
be the same.
This only applies to matrix multiplication.
Element-wise addition, multiplication, and division are still
evaluated from left to right.
.SH AUTHOR
Greg Ward
.SH "SEE ALSO"
cnt(1), getinfo(1), histo(1), neaten(1), rcalc(1), rcollate(1),
rcontrib(1), rfluxmtx(1), rlam(1), 
rsplit(1), tabfunc(1), total(1), wrapBSDF(1)
Revision:	1.14
Committed:	Mon Aug 12 02:26:46 2019 UTC (5 years, 8 months ago) by greg
Branch:	MAIN
Changes since 1.13:	+10 -1 lines
Log Message:	Added support for trailing unary operations on final matrix result
#	Content
1	.\" RCSid "$Id: rmtxop.1,v 1.13 2019/08/12 01:20:25 greg Exp $"
2	.TH RMTXOP 1 7/8/97 RADIANCE
3	.SH NAME
4	rmtxop - concatenate, add, multiply, divide, transpose, scale, and convert matrices
5	.SH SYNOPSIS
6	.B rmtxop
7	[
8	.B \-v
9	][
10	.B \-f[afdc]
11	][
12	.B \-t
13	][
14	.B "\-s sf .."
15	][
16	.B "\-c ce .."
17	]
18	.B m1
19	[
20	.B ".+*/"
21	]
22	.B ".."
23	.SH DESCRIPTION
24	.I Rmtxop
25	loads and concatenates or adds/multiplies/divides
26	together component matrix files given on the command line.
27	Each file must have a header containing the following variables:
28	.sp
29	.nf
30	NROWS={number of rows}
31	NCOLS={number of columns}
32	NCOMP={number of components}
33	FORMAT={ascii\|float\|double\|32-bit_rle_rgbe\|32-bit_rle_xyze}
34	.sp
35	.fi
36	The number of components indicates that each matrix element is actually
37	composed of multiple elements, most commonly an RGB triple.
38	This is essentially dividing the matrix into planes, where each component
39	participates in a separate calculation.
40	If an appropriate header is not present, it may be added with a call to
41	.I rcollate(1).
42	A matrix may be read from the standard input using a hyphen by itself ('-')
43	in the appropriate place on the command line.
44	.PP
45	Any of the matrix inputs may be read from a command
46	instead of a file by
47	using quotes and a beginning exclamation point ('!').
48	.PP
49	Two special cases are handled for component matrices that are either
50	XML files containing BTDF data, or Radiance picture files.
51	In the first case, a BSDF library is used to load and interpret the
52	transmission matrix.
53	(XML files cannot be read from the standard input or from a command.)\0
54	In the second case, the RGBE or XYZE values are loaded in a 3-component
55	matrix where the number of columns match the X-dimension of the picture, and
56	the number of rows match the Y-dimension.
57	The picture must be in standard pixel ordering, and the first row
58	is at the top with the first column on the left.
59	.PP
60	Before each file, the
61	.I \-t
62	and
63	.I \-s
64	or
65	.I \-c
66	options may be used to modify the matrix.
67	The
68	.I \-t
69	option transposes the matrix, swapping rows and columns.
70	The
71	.I \-s
72	option applies the given scalar factor(s) to the elements of the matrix.
73	If only one factor is provided,
74	it will be used for all components.
75	If multiple factors are given, their number must match the number of matrix
76	components.
77	Alternatively, the
78	.I \-c
79	option may be used to "transform" the element values, possibly changing
80	the number of components in the matrix.
81	For example, a 3-component matrix can be transformed into a single-component
82	matrix by using
83	.I \-c
84	with three coefficients.
85	A four-component matrix can be turned into a two-component matrix using 8
86	coefficients, where the first four coefficients will be used to compute
87	the first new component, and the second four coefficients
88	yield the second new component.
89	Note that the number of coefficients must be an even multiple of the number
90	of original components.
91	The
92	.I \-s
93	and
94	.I \-c
95	options are mutually exclusive, insofar as they cannot be applied together
96	to the same input matrix.
97	.PP
98	If present, the second and subsequent matrices on the command
99	line are concatenated to the result unless separated by a plus ('+'),
100	asterisk ('*'), or forward slash ('/') symbol,
101	in which case the matrix elements are added, multiplied, or divided together,
102	respectively.
103	(Note that the asterisk must be quoted or escaped in most shells.)\0
104	In the case of addition, the two matrices involved must have the same number
105	of components.
106	For element-wise multiplication and division, the second matrix is
107	permitted instead to have a single component per element, which will be
108	applied equally to all components of the first matrix.
109	If element-wise division is specified, any zero elements in the second
110	matrix will result in a warning and the corresponding component(s) in the
111	first matrix will be set to zero.
112	.PP
113	The number of components in the new matrix after applying any
114	.I -c
115	transform must agree with the prior result.
116	For concatenation (matrix multiplication), the number of columns
117	in the prior result must equal the number of rows in the new matrix, and
118	the result will have the number of rows of the previous and the number
119	of columns of the new matrix.
120	In the case of addition, multiplication, and division,
121	the number of rows and columns of the prior result and the
122	new matrix must match, and will not be changed by the operation.
123	.PP
124	A final transpose or scaling/transform operation may be applied to
125	the results by appending the
126	.I \-t
127	and
128	.I \-s
129	or
130	.I \-c
131	options after the last matrix on the command line.
132	.PP
133	Results are sent to the standard output.
134	By default, the values will be written in the lowest resolution format
135	among the inputs, but the
136	.I \-f
137	option may be used to explicitly output components
138	as ASCII (-fa), binary doubles (-fd), floats (-ff), or RGBE colors (-fc).
139	In the latter case, the actual matrix dimensions are written in the resolution
140	string rather than the header.
141	Also, matrix results written as Radiance pictures must have either one
142	or three components.
143	In the one-component case, the output is written as grayscale.
144	.PP
145	The
146	.I \-v
147	option turns on verbose reporting, which announces each operation.
148	.SH EXAMPLES
149	To concatenate two matrix files with a BTDF between them and write
150	the result as binary double:
151	.IP "" .2i
152	rmtxop -fd view.vmx blinds.xml exterior.dmx > dcoef.dmx
153	.PP
154	To convert a BTDF matrix into a Radiance picture:
155	.IP "" .2i
156	rmtxop -fc blinds.xml > blinds.hdr
157	.PP
158	To scale a matrix by 4 and add it to the transpose of another matrix:
159	.IP "" .2i
160	rmtxop -s 4 left.mtx + -t right.mtx > result.mtx
161	.PP
162	To send the elements of a binary matrix to
163	.I rcalc(1)
164	for further processing:
165	.IP "" .2i
166	rmtxop -fa orig.mtx \| rcollate -ho -oc 1 \| rcalc [operations]
167	.SH NOTES
168	Matrix multiplication is associative but not commutative, so order
169	matters to the result.
170	.I Rmtxop
171	takes advantage of the associative property to evaluate the
172	implicit equation from right to left when this reduces the
173	number of basic operations.
174	If the rightmost matrix is a column vector for example, it is
175	much faster to concatenate from the right, and the result should
176	be the same.
177	This only applies to matrix multiplication.
178	Element-wise addition, multiplication, and division are still
179	evaluated from left to right.
180	.SH AUTHOR
181	Greg Ward
182	.SH "SEE ALSO"
183	cnt(1), getinfo(1), histo(1), neaten(1), rcalc(1), rcollate(1),
184	rcontrib(1), rfluxmtx(1), rlam(1),
185	rsplit(1), tabfunc(1), total(1), wrapBSDF(1)