gview(1) - Plan 9 from User Space

From 78e51a8c6678b6e3dff3d619aa786669f531f4bc Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 03:45:44 +0000 Subject: checkpoint --- man/man1/gview.html | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 man/man1/gview.html (limited to 'man/man1/gview.html') diff --git a/man/man1/gview.html b/man/man1/gview.html new file mode 100644 index 00000000..6abdc7da --- /dev/null +++ b/man/man1/gview.html @@ -0,0 +1,155 @@ + +gview(1) - Plan 9 from User Space + + + + +

GVIEW(1) GVIEW(1) +

+
+

NAME
+ +
+ + gview – interactive graph viewer
+ +
+

SYNOPSIS
+ +
+ + gview [ −l logfile ] [ −m ] [ file ]
+ +
+

DESCRIPTION
+ +
+ + Gview reads polygonal lines or a polygonal line drawing from an + ASCII input file (which defaults to standard input), and views + it interactively, with commands to zoom in and out, perform simple + editing operations, and display information about points and polylines. + The editing commands can change the color and + thickness of the polylines, delete (or undelete) some of them, + and optionally rotate and move them. It is also possible to generate + an output file that reflects these changes and is in the same + format as the input. +
+ + Since the move and rotate commands are undesirable when just viewing + a graph, they are only enabled if gview is invoked with the −m + option. +
+ + Clicking on a polyline with button 1 displays the coordinates + and a t value that tells how far along the polyline. (t=0 at the + first vertex, t=1 at the first vertex, t=1.5 halfway between the + second and third vertices, etc.) The −l option generates a log + file that lists all points selected in this manner. +
+ + The most important interactive operations are to zoom in by sweeping + out a rectangle, or to zoom out so that everything currently being + displayed shrinks to fit in the swept-out rectangle. Other options + on the button 3 menu are unzoom which restores the coordinate + system to the default state where everything fits on + the screen, recenter which takes a point and makes it the center + of the window, and square up which makes the horizontal and vertical + scale factors equal. +
+ + To take a graph of a function where some part is almost linear + and see how it deviates from a straight line, select two points + on this part of the graph (i.e., select one with button 1 and + then select the other) and then use the slant command on the button + 3 menu. This slants the coordinate system so that the line + between the two selected points appears horizontal (but vertical + still means positive y). Then the zoom in command can be used + to accentuate deviations from horizontal. There is also an unslant + command that undoes all of this and goes back to an unslanted + coordinate system. +
+ + There is a recolor command on button 3 that lets you select a + color and change everything to have that color, and a similar + command on button 2 that only affects the selected polyline. The + thick or thin command on button 2 changes the thickness of the + selected polyline and there is also an undo command for such + edits. +
+ + Finally, button 3 had commands to read a new input file and display + it on top of everything else, restack the drawing order (in case + lines of different color are drawn on top of each other), write + everything into an output file, or exit the program. +
+ + Each polyline in an input or output file is a space-delimited + x y coordinate pair on a line by itself, and the polyline is a + sequence of such vertices followed by a label. The label could + be just a blank line or it could be a string in double quotes, + or virtually any text that does not contain spaces and is on a + line by itself. The + label at the end of the last polyline is optional. It is not legal + to have two consecutive labels, since that would denote a zero-vertex + polyline and each polyline must have at least one vertex. (One-vertex + polylines are useful for scatter plots.)
+ If the label after a polyline can contains the word Thick or a + color name (Red, Pink, Dkred, Orange, Yellow, Dkyellow, Green, + Dkgreen, Cyan, Blue, Ltblue, Magenta, Violet, Gray, Black, White), + whichever color name comes first will be used to color the polyline. + +
+

EXAMPLE
+ +
+ + To see a graph of the function y=sin(x)/x generate input with + an awk script and pipe it into gview:
+ +
+ + awk 'BEGIN{for(x=.1;x<500;x+=.1)print x,sin(x)/x}' | gview + +
+ +
+

SOURCE
+ +
+ + /usr/local/plan9/src/cmd/draw/gview.c + +
+

SEE ALSO
+ +
+ + awk(1)
+ +
+

BUGS
+ +
+ + The user interface for the slant command is counter-intuitive. + Perhaps it would be better to have a scheme for sweeping out a + parallelogram.
+ +
+ +

+ + +

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+ + -- cgit v1.2.3