postmd(1) (Line Printer Spooling Utilities) postmd(1)
NAME
postmd - matrix display program for PostScript printers
SYNOPSIS
postmd [options] [files]
DESCRIPTION
The postmd filter reads a series of floating point numbers from
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 files are specified, or if - is one of the input
files, the standard input is read. The following options are
understood:
-b num Pack the bitmap in the output file using num byte patterns.
A value of 0 turns off all packing of the output file. By
default, num is 6.
-c num Print num copies of each page. By default, only one copy
is printed.
-d dimen Sets the default matrix dimensions for all input files to
dimen. The dimen string can be given as rows or
rowsxcolumns. If columns is omitted it will be set to
rows. By default, 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.
-g list 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
-i option. 255 corresponds to white, and 0, to black. The
postmd filter assigns a default gray scale that omits white
(that is, 255) and gets darker as the regions move from
left to right along the real line.
-i list List is a comma, space or slash(/) separated string of N
floating point numbers that partition the real line into
2N+1 regions. The list must be given in increasing
numerical order. The partitions are used to map floating
point numbers read from the input files into gray scale
integers that are either assigned automatically by postmd
or arbitrarily selected using the -g option. The default
interval list is -1,0,1, which partions the real line into
seven regions.
-m num Magnify each logical page by the factor num. Pages are
scaled uniformly about the origin which, by default, is
located at the center of each page. The default
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postmd(1) (Line Printer Spooling Utilities) postmd(1)
magnification is 1.0.
-n num Print num logical pages on each piece of paper, where num
can be any positive integer. By default, num is set to 1.
-o list Print pages whose numbers are given in the comma separated
list. The list contains single numbers N and ranges N1 -
N2. A missing N1 means the lowest numbered page, a missing
N2 means the highest.
-p mode Print files in either portrait or landscape mode. Only the
first character of mode is significant. The default mode
is portrait.
-w window 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 files. Row and
column indices start at 1 in the upper left corner and the
numbers in the input files are assumed to be written in row
major order. By default, the entire matrix is displayed.
-x num Translate the origin 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 num moves everything
right. The default offset is 0 inches.
-y num Translate the origin num inches along the positive y axis.
Positive num moves everything up the page. The default
offset is 0.
Only one matrix is displayed on each logical page, and each of the
input 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, 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 with the -d option overrides
this default behavior, and in that case the dimensions apply to all
input files.
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 apply only to the current input file.
Recognized header keywords are dimension, interval, grayscale, and
window. The syntax of the value string that follows each keyword
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postmd(1) (Line Printer Spooling Utilities) postmd(1)
parallels what's accepted by the -d, -i, -g, and -w options.
EXAMPLES
For example, suppose file initially contains the 1000 numbers in a
20x50 matrix. Then you can produce exactly the same output by
completing three steps. First, issue the following command line:
postmd -d20x50 -i"-100 100" -g0,128,254,128,0 file
Second, prepend the following header to file:
dimension 20x50
interval -100.0 .100e+3
grayscale 0 128 254 128 0
Third, issue the following command line:
postmd file
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 (that is, black), numbers equal to -100 or 100 into 128 (that is,
50 percent black), and numbers between -100 and 100 into 254 (that
is, almost white).
NOTES
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 600x600 matrix is an optimistic upper bound for a two
element interval list (that is, five regions) using 8.5x11 inch paper
on a 300 dpi printer.
Using white (that is, 255) in a gray scale list is not recommended
and won't show up in the legend and bar graph that postmd displays
below each image.
DIAGNOSTICS
An exit status of 0 is returned if files were successfully processed.
FILES
/usr/lib/postscript/postmd.ps
/usr/lib/postscript/forms.ps
/usr/lib/postscript/ps.requests
SEE ALSO
dpost(1), postdaisy(1), postdmd(1), postio(1), postprint(1),
postreverse(1), posttek(1).
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