postmd.1

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

.ds dQ /usr/lib/postscript
.TH POSTMD 1 "DWB 3.2"
.SH NAME
.B postmd
\- matrix display program for PostScript printers
.SH SYNOPSIS
\*(mBpostmd\f1
.OP "" options []
.OP "" files []
.SH DESCRIPTION
.B postmd
reads a series of floating point numbers from
.IR files ,
translates them into a PostScript gray scale image,
and writes the results on the standard output.
In a typical application the numbers might be
the elements of a large matrix,
written in row major order,
while the printed image could help locate
patterns in the matrix.
If no
.I files
are specified, or if
.OP \-
is one of the input
.IR files ,
the standard input is read.
The following
.I options
are understood:
.TP 0.75i
.OP \-b num
Pack the bitmap in the output file using
.I num
byte patterns.
A value of 0 turns off all packing of the output file.
By default
.I num
is 6.
.TP
.OP \-c num
Print
.I num
copies of each page.
By default only one copy is printed.
.TP
.OP \-d dimen
Sets the default matrix dimensions for all input
.I files
to
.IR dimen .
The
.I dimen
string can be given as rows or rows\^\(mu\^columns.
If columns is omitted it will be set to rows.
By default
.B postmd
assumes each matrix is square and sets the number of rows
and columns to the square root of the number of elements in
each input file.
.TP
.OP \-g list
.I list
is a comma- or space-separated string of integers, each lying between
0 and 255 inclusive,
that assigns PostScript gray scales to the regions of the real line
selected by the
.OP \-i
option.
255 corresponds to white and 0 to black.
.B postmd
assigns a default gray scale that omits white (i.e., 255) and gets
darker as the regions move from left to right along the real line.
.TP
.OP \-i list
.I list
is a comma- or space-separated string of
.I N
floating point numbers that
partition the real line into
.RI 2 N +1
regions.
The
.I list
must be given in increasing numerical order.
The partitions are used to map floating point numbers read from the input
.I files
into gray scale integers that are assigned automatically by
.B postmd
or arbitrarily selected using the
.OP \-g
option.
The default interval
.I list
is ``\*(mB\-1,0,1\fP'' which partions the real line into 7 regions.
.TP
.OP \-m num
Magnify each logical page by the factor
.IR num .
Pages are scaled uniformly about the origin,
which by default is located at the center of
each page.
The default magnification is 1.0.
.TP
.OP \-n num
Print
.I num
logical pages on each piece of paper,
where
.I num
can be any positive integer.
By default
.I num
is set to 1.
.TP
.OP \-o list
Print pages whose numbers are given in the comma separated
.IR list .
The list contains single numbers
.I N
and ranges
.IR N1\-\|N2 .
A missing
.I N1
means the lowest numbered page, a missing
.I N2
means the highest.
.TP
.OP \-p mode
Print
.I files
in either \*(mBportrait\fP or \*(mBlandscape\fP
.IR mode .
Only the first character of
.I mode
is significant.
The default
.I mode
is \*(mBportrait\fP.
.TP
.OP \-w window
.I window
is a comma- or space-separated list of four positive integers that
select the upper left and lower right corners of a submatrix from
each of the input
.IR files .
Row and column indices start at 1 in the upper left corner and the
numbers in the input
.I files
are assumed to be written in row major order.
By default the entire matrix is displayed.
.TP
.OP \-x num
Translate the origin
.I num
inches along the positive x axis.
The default
coordinate system has the origin fixed at the
center of the page, with positive
x to the right and positive y up the page.
Positive
.I num
moves everything right.
The default offset is 0 inches.
.TP
.OP \-y num
Translate the origin
.I num
inches along the positive y axis.
Positive
.I num
moves everything up the page.
The default offset is 0.
.TP
.OP \-E name
Set the character encoding for text fonts to
.IR name .
Requesting
.I name
means include file
.MI \*(dQ/ name .enc \f1.
A nonexistent encoding file is silently ignored.
The default selects file
.MR \*(dQ/Default.enc .
.TP
.OP \-L file
Use
.I file
as the PostScript prologue.
.br
The default is
.MR \*(dQ/postmd.ps .
.PP
Three options allow insertion of arbitrary PostScript
at controlled points in the translation process:
.TP 0.75i
.OP \-C file
Copy
.I file
to the output file;
.I file
must contain legitimate PostScript.
.TP
.OP \-P string
Include
.I string
in the output file;
.I string
must be legitimate PostScript.
.TP
.OP \-R action
Requests special
.I action
(e.g.,
.MR manualfeed )
on a per page or global basis.
The
.I action
string can be given as
.IR request ,
.IM request : page\f1\|,
or
.IM request : page : file\f1\|.
If
.I page
is omitted or given as 0, the request
applies to all pages.
If
.I file
is omitted, the request
lookup is done in
.MR \*(dQ/ps.requests .
.PP
Only one matrix is displayed on each logical page,
and each of the input
.I files
must contain complete descriptions of exactly one matrix.
Matrix elements are floating point numbers arranged in row major order in
each input file.
White space, including newlines, is not used to determine matrix
dimensions.
By default
.B postmd
assumes each matrix is square and sets the number of rows and columns
to the square root of the number of elements in the input file.
Supplying default dimensions on the command line using the
.OP \-d
option overrides this default behavior, and in that case the
dimensions apply to all input
.IR files .
.PP
An optional header can be supplied with each input file and is used
to set the matrix dimensions, the partition of the real line, the gray scale
map, and a window into the matrix.
The header consists of keyword/value pairs, each on a separate line.
It begins on the first line of each input file and ends with the
first unrecognized string, which should be the first matrix element.
Values set in the header take precedence, but only apply to the
current input file.
Recognized header keywords are
.MR dimension ,
.MR interval ,
.MR grayscale ,
and
.MR window .
The syntax of the value string that follows each keyword parallels what is
accepted by the
.OP \-d ,
.OP \-i ,
.OP \-g ,
and
.OP \-w
options.
.SH EXAMPLES
For example, suppose
.I file
initially contains the 1000 numbers
in a 20\(mu50 matrix.
Then the command line:
.EX
postmd -d20x50 -i"-100 100" -g0,128,254,128,0 \f2file
.EE
and prepending the header,
.EX
dimension 20x50
interval -100.0 .100e+3
grayscale 0 128 254 128 0
.EE
to
.I file
and typing the command line:
.EX
postmd \f2file
.EE
produce exactly the same output.
The interval list partitions the real line into five regions and
the gray scale list maps numbers less than \-100 or greater than 100
into 0 (i.e., black), numbers equal to \-100 or 100 into 128
(i.e., 50 percent
black), and numbers between \-100 and 100 into 254 (i.e., almost white).
.SH DIAGNOSTICS
A 0 exit status is returned if
.I files
were successfully processed.
.SH WARNINGS
The largest matrix that can be adequately displayed is a function
of the interval and gray scale lists, the printer resolution,
and the paper size.
A 600\(mu600 matrix is an optimistic upper bound for a two element interval
list (i.e. five regions) using 8.5\(mu11 inch paper on a 300 dpi printer.
.PP
Using white (i.e., 255) in a gray scale list is not recommended and will not
show up in the legend and bar graph that
.B postmd
displays below each image.
.SH FILES
.MW \*(dQ/postmd.ps
.br
.MW \*(dQ/forms.ps
.br
.MW \*(dQ/ps.requests
.SH SEE ALSO
.BR dpost (1),
.BR postdaisy (1),
.BR postdmd (1),
.BR postio (1),
.BR postprint (1),
.BR postreverse (1),
.BR posttek (1),
.BR psencoding (1)