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Manpages WindowSection: User Contributed Perl Documentation (3)Updated: 2001-11-09 Index Return to Main Contents NAMEPDL::Graphics::PGPLOT::Window - A OO interface to PGPLOT windowsSYNOPSISperldl> use PDL::Graphics::PGPLOT::Window perldl> $win = PDL::Graphics::PGPLOT::Window->new(Device => '/xs'); perldl> $a = pdl [1..100] perldl> $b = sqrt($a) perldl> $win->line($b) perldl> $win->hold() perldl> $c = sin($a/10)*2 + 4 perldl> $win->line($c)In the following documentation the commands are not shown in their OO versions. This is for historical reasons and should not cause too much trouble. DESCRIPTIONThis package offers a OO interface to the PGPLOT plotting package. This is intended to replace the traditional interface in PDL::Graphics::PGPLOT and contains interfaces to a large number of PGPLOT routines. Below the usage examples for each function tend to be given in the non-OO version for historical reasons. This will slowly be changed, but in the meantime refer to the section on OO-interface below to see how to convert the usage information below to OO usage (it is totally trivial).PDL::Graphics::PGPLOT::Window is an interface to the PGPLOT graphical libraries. The list of currently availably methods:
imag - Display an image (uses pgimag()/pggray() as appropriate) ctab - Load an image colour table ctab_info - Get information about currently loaded colour table line - Plot vector as connected points points - Plot vector as points errb - Plot error bars cont - Display image as contour map bin - Plot vector as histogram (e.g. bin(hist($data)) ) hi2d - Plot image as 2d histogram (not very good IMHO...) poly - Draw a polygon vect - Display 2 images as a vector field text - Write text in the plot area label_axes - Print axis titles legend - Create a legend with different texts, linestyles etc. cursor - Interactively read cursor positions. circle - Draw a circle ellipse - Draw an ellipse.Device manipulation commands:
new - Constructor for a new PGPLOT output device close - Close a PGPLOT output device focus - Set focus to the given device. This should normally be done behind the scenes. hold - Hold current plot window range - allows overlays etc. release - Release back to autoscaling of new plot window for each command held - Returns true if the graphics is held on the current device. env - Define a plot window, put on 'hold' panel - Move to a specified plot panel when several panels are defined. erase - Erase the current window (or panel) options - Get the options set for the present output device id - The ID for the device device - The device type name - The window nameNotes: $transform for image/cont etc. is used in the same way as the "TR()" array in the underlying PGPLOT FORTRAN routine but is, fortunately, zero-offset. The "transform()" routine can be used to create this piddle. For completeness: The transformation array connect the pixel index to a world coordinate such that:
X = tr[0] + tr[1]*i + tr[2]*j Y = tr[3] + tr[4]*i + tr[5]*j Variable passing and extensionsIn general variables are passed to the pgplot routines by using "get_dataref" to get the reference to the values. Before passing to pgplot routines however, the data are checked to see if they are in accordance with the format (typically dimensionality) required by the PGPLOT routines. This is done using the routine "checkarg" (internal to PGPLOT). This routine checks the dimensionality of the input data. If there are superfluous dimensions of size 1 they will be trimmed away until the dimensionality is correct. Example:Assume a piddle with dimensions (1,100,1,1) is passed to "line", which expects its inputs to be vectors. "checkarg" will then return a piddle with dimensions (100). If instead the same piddle was passed to "imag", which requires 2D piddles as output, "checkarg" would return a piddle with dimensionality (100, 1) (Dimensions are removed from the start) Thus, if you want to provide support for another PGPLOT function, the structure currently look like this (there are plans to use the Options package to simplify the options parsing):
# Extract the hash(es) on the commandline ($arg, $opt)=_extract_hash(@_); <Check the number of input parameters> <deal with $arg> checkarg($x, 3); # For a hypothetical 3D routine. ... pgcube($n, $x->get_dataref); 1; Setting optionsAll routines in this package take a hash with options as an optional input. This options hash can be used to set parameters for the subsequent plotting without going via the PGPLOT commands.This is implemented such that the plotting settings (such as line width, line style etc.) are affected only for that plot, any global changes made, say, with "pgslw()" are preserved. Some modifications apply when using the OO interface, see below. Alphabetical listing of standard optionsThe following options are always parsed. Whether they have any importance depend on the routine invoked - e.g. line style is irrelevant for "imag", or the "justify" option is irrelevant if the display is on 'hold'. This is indicated in the help text for the commands below.The options are not case sensitive and will match for unique substrings, but this is not encouraged as obscure options might invalidate what you thought was a unique substring. In the listing below examples are given of each option. The actual option can then be used in a plot command by specifying it as an argument to the function wanted (it can be placed anywhere in the command list). E.g:
$opt={COLOR=>2}; line $x, $y, $opt; # This will plot a line with red color
OBJECT-ORIENTED INTERFACEThis section will briefly describe how the PDL::Graphics::PGPLOT::Window package can be used in an object-oriented (OO) approach and what the advantages of this would be. We will start with the latter
Anyway, enough philosophizing, let us get down to Earth and give some examples of the use of OO PGPLOT. As an example we will take Odd (which happens to be a common Norwegian name) who is monitoring the birth of rabbits in O'Fib-o-nachy's farm (alternatively he can of course be monitoring processes or do something entirely different). Odd wants the user to be able to monitor both the birth rates and accumulated number of rabbits and the spatial distribution of the births. Since these are logically different he chooses to have two windows open:
$rate_win = PDL::Graphics::PGPLOT::Window->new(Device => '/xw', Aspect => 1, WindowWidth => 5, NXPanel => 2); $area_win = PDL::Graphics::PGPLOT::Window->new(Device => '/xw', Aspect => 1, WindowWidth => 5);See the documentation for new below for a full overview of the options you can pass to the constructor. Next, Odd wants to create plotting areas for subsequent plots and maybe show the expected theoretical trends
$rate_win->env(0, 10, 0, 1000, {XTitle => 'Days', YTitle => '#Rabbits'}); $rate_win->env(0, 10, 0, 100, {Xtitle=>'Days', Ytitle => 'Rabbits/day'}); $area_win->env(0, 1, 0, 1, {XTitle => 'Km', Ytitle => 'Km'}); # And theoretical prediction. $rate_win->line(sequence(10), fibonacci(10), {Panel => [1, 1]});That is basically it. The commands should automatically focus the relevant window. Due to the limitations of PGPLOT this might however lead you to plot in the wrong panel... The package tries to be smart and do this correctly, but might get it wrong at times. STATE and RECORDINGA new addition to the graphics interface is the ability to record plot commands. This can be useful when you create a nice-looking plot on the screen that you want to re-create on paper for instance. Or if you want to redo it with slightly changed variables for instance. This is still under development and views on the interface are welcome.The functionality is somewhat detached from the plotting functions described below so I will discuss them and their use here. Recording is off by default. To turn it on when you create a new device you can set the "Recording" option to true, or you can set the $PDL::Graphics::PGPLOT::RECORDING variable to 1. I recommend doing the latter in your ".perldlrc" file at least since you will often have use for recording in the perldl script. Use of recordingThe recording is meant to help you recreate a plot with new data or to a different device. The most typical situation is that you have created a beautiful plot on screen and want to have a Postscript file with it. In the dreary old world you needed to go back and execute all commands manually, but with this wonderful new contraption, the recorder, you can just replay your commands:
dev '/xs', {Recording => 1} $x = sequence(10) line $x, $x**2, {Linestyle => 'Dashed'} $s = retrieve_state() # Get the current tape out of the recorder. dev '/cps' replay $sThis should result in a "pgplot.ps" file with a parabola drawn with a dashed line. Note the command "retrieve_state" which retrieves the current state of the recorder and return an object (of type PDL::Graphics::State) that is used to replay commands later. Controlling the recordingLike any self-respecting recorder you can turn the recorder on and off using the "turn_on_recording" and "turn_off_recording" respectively. Likewise you can clear the state using the "clear_state" command.
$w=PDL::Graphics::PGPLOT::Window->new(Device => '/xs'); $w->turn_on_recording; $x=sequence(10); $y=$x*$x; $w->line($x, $y); $w->turn_off_recording; $w->line($y, $x); $w->turn_on_recording; $w->line($x, $y*$x); $state = $w->retrieve_state();We can then replay $state and get a parabola and a cubic plot.
$w->replay($state); Tips and Gotchas!The data are stored in the state object as references to the real data. This leads to one good and one potentially bad consequence:
FUNCTIONSA more detailed listing of the functions and their usage follows. For all functions we specify which options take effect and what other options exist for the given function. The function descriptions below are all given for the non-OO usage for historical reasons, but since the conversion to an OO method is trivial there is no major need for concern. Whenever you see a function example of the form
Usage: a_simple_function($x, $y, $z [, $opt]);and you wish to use the OO version, just let your mind read the above line as:
Usage: $win->a_simple_function($x, $y, $z [, $opt]);where $win is a PDL::Graphics::PGPLOT::Window object. That is all. Window control functions.newConstructor for PGPLOT object/device/plot window.
Usage: PDL::Graphics::PGPLOT::Window->new($opt); Usage: PDL::Graphics::PGPLOT::Window->new($option=>$value,...);Options to new() can either be specified via a reference to a hash
$win = PDL::Graphics::PGPLOT::Window->new({Dev=>'/xserve',ny=>2});or directly, as an array
# NOTE: no more {} ! $win = PDL::Graphics::PGPLOT::Window->new(Dev=>'/xserve',ny=>2);The following lists the recognised options:
An important point to note is that the default values of most options can be specified by passing these to the constructor. All general options (common to several functions) can be adjusted in such a way, but function specific options can not be set in this way (this is a design limitation which is unlikely to be changed). Thus the following call will set up a window where the default axis colour will be yellow and where plot lines normally have red colour and dashed linestyle.
$win = PDL::Graphics::PGPLOT::Window->new(Device => '/xs', AxisColour => 'Yellow', Colour => 'Red', LineStyle => 'Dashed'); closeClose a plot window
Usage: $win->close()Close the current window. This does not necessarily mean that the window is removed from your screen, but it does ensure that the device is closed. A message will be printed to STDOUT giving the name of the file created if the plot was made to a hardcopy device and $PDL::verbose is true. heldCheck if a window is on hold
$is_held = $win->held();Function to check whether the window is held or not. holdHold the present window.
Usage: $win->hold()Holds the present window so that subsequent plot commands overplots. panelSwitch to a different panel
$win->panel(<num>);Move to a different panel on the plotting surface. Note that you will need to erase it manually if that is what you require. releaseRelease a plot window.
$win->release()Release a plot window so that subsequent plot commands move to the next panel or erase the plot and create a new plot. eraseErase plot
$win->erase($opt);Erase a plot area. This accepts the option "Panel" or alternatively a number or array reference which makes it possible to specify the panel to erase when working with several panels. Plotting functionsenvDefine a plot window, and put graphics on 'hold'
$win->env( $xmin, $xmax, $ymin, $ymax, [$justify, $axis] ); $win->env( $xmin, $xmax, $ymin, $ymax, [$options] );$xmin, $xmax, $ymin, $ymax are the plot boundaries. $justify is a boolean value (default is 0); if true the axes scales will be the same (see ``justify''). $axis describes how the axes should be drawn (see ``axis'') and defaults to 0. If the second form is used, $justify and $axis can be set in the options hash, for example:
$win->env( 0, 100, 0, 50, {JUSTIFY => 1, AXIS => 'GRID', CHARSIZE => 0.7} );In addition the following options can also be set for "env":
label_axesLabel plot axes
$win->label_axes(<xtitle>, <ytitle>, <plot title>, $options);Draw labels for each axis on a plot. imagDisplay an image (uses "pgimag()"/"pggray()" as appropriate)
$win->imag ( $image, [$min, $max, $transform], [$opt] )Notes: $transform for image/cont etc. is used in the same way as the "TR()" array in the underlying PGPLOT FORTRAN routine but is, fortunately, zero-offset. The "transform()" routine can be used to create this piddle. There are several options related to scaling. By default, the image is scaled to fit the PGPLOT default viewport on the screen. Scaling, aspect ratio preservation, and 1:1 pixel mapping are available. (1:1 pixel mapping GREATLY increases the speed of pgimag, and is useful for, eg, movie display; but it's not recommended for final output as it's not device-independent.) To draw a colour bar (or wedge), either use the "DrawWedge" option, or the "draw_wedge()" routine (once the image has been drawn). Options recognised:
ITF - the image transfer function applied to the pixel values. It may be one of 'LINEAR', 'LOG', 'SQRT' (lower case is acceptable). It defaults to 'LINEAR'. MIN - Sets the minimum value to be used for calculation of the display stretch MAX - Sets the maximum value for the same TRANSFORM - The transform 'matrix' as a 6x1 vector for display PIX - Sets the image pixel aspect ratio. By default, imag stretches the image pixels so that the final image aspect ratio fits the viewport exactly. Setting PIX=>1 causes the image aspect ratio to be preserved. (the image is scaled to avoid cropping, unless you specify scaling manually). Larger numbers yield "landscape mode" pixels. PITCH - Sets the number of image pixels per screen unit, in the Y direction. The X direction is determined by PIX, which defaults to 1 if PITCH is specified and PIX is not. PITCH causes UNIT to default to "inches" so that it is easy to say 100dpi by specifying {PITCH=>100}. Larger numbers yield higher resolution (hence smaller appearing) images. UNIT - Sets the screen unit used for scaling. Must be one of the PGPLOT supported units (inch, mm, pixel, normalized). You can refer to them by name or by number. Defaults to pixels if not specified. SCALE - Syntactic sugar for the reciprocal of PITCH. Makes the UNIT default to "pixels" so you can say "{SCALE=>1}" to see your image in device pixels. Larger SCALEs lead to larger appearing images. DrawWedge - set to 1 to draw a colour bar (default is 0) Wedge - see the draw_wedge() routineThe following standard options influence this command:
AXIS, BORDER, JUSTIFY To see an image with maximum size in the current window, but square pixels, say: $win->imag( $a, { PIX=>1 } ); An alternative approach is to try: $win->imag( $a, { JUSTIFY=>1 } ); To see the same image, scaled 1:1 with device pixels, say: $win->imag( $a, { SCALE=>1 } ); To see an image made on a device with 1:2 pixel aspect ratio, with X pixels the same as original image pixels, say $win->imag( $a, { PIX=>0.5, SCALE=>2 } ); To display an image at 100 dpi on any device, say: $win->imag( $a, { PITCH=>100 } ); To display an image with 100 micron pixels, say: $win->imag( $a, { PITCH=>10, UNIT=>'mm' } ); imag1Display an image with correct aspect ratio
$win->imag1 ( $image, [$min, $max, $transform], [$opt] )This is syntactic sugar for
$win->imag( { PIX=>1 } ); draw_wedgeAdd a wedge (colour bar) to an image.
$win->draw_wedge( [$opt] )Adds a wedge - shows the mapping between colour and value for a pixel - to the current image. This can also be achieved by setting "DrawWedge" to 1 when calling the "imag" routine. The colour and font size are the same as used to draw the image axes (although this will probably fail if you did it yourself). To control the size and location of the wedge, use the "Wedge" option, giving it a hash reference containing any of the following:
$a = rvals(50,50); $win = PDL::Graphics::PGPLOT::Window->new(); $win->imag( $a, { Justify => 1, ITF => 'sqrt' } ); $win->draw_wedge( { Wedge => { Width => 4, Label => 'foo' } } ); # although the following might be more sensible $win->imag( $a, { Justify => 1, ITF => 'sqrt', DrawWedge => 1, Wedge => { Width => 4, Label => 'foo'} } ); ctabLoad an image colour table.
Usage: ctab ( $name, [$contrast, $brightness] ) # Builtin col table ctab ( $ctab, [$contrast, $brightness] ) # $ctab is Nx4 array ctab ( $levels, $red, $green, $blue, [$contrast, $brightness] ) ctab ( '', $contrast, $brightness ) # use last color tableNote: See PDL::Graphics::LUT for access to a large number of colour tables. linePlot vector as connected pointsIf the 'MISSING' option is specified, those points in the $y vector which are equal to the MISSING value are not plotted, but are skipped over. This allows one to quickly draw multiple lines with one call to "line", for example to draw coastlines for maps.
Usage: line ( [$x,] $y, [$opt] )The following standard options influence this command:
AXIS, BORDER, COLO(U)R, JUSTIFY, LINESTYLE, LINEWIDTH, MISSING $x = sequence(10)/10.; $y = sin($x)**2; # Draw a red dot-dashed line line $x, $y, {COLOR => 'RED', LINESTYLE=>3}; pointsPlot vector as points
Usage: points ( [$x,] $y, [$symbol(s)], [$opt] )Options recognised:
SYMBOL - Either a piddle with the same dimensions as $x, containing the symbol associated to each point or a number specifying the symbol to use for every point, or a name specifying the symbol to use according to the following (recognised name in capital letters): 0 - SQUARE 1 - DOT 2 - PLUS 3 - ASTERISK 4 - CIRCLE 5 - CROSS 7 - TRIANGLE 8 - EARTH 9 - SUN 11 - DIAMOND 12- STAR PLOTLINE - If this is >0 a line will be drawn through the points.The following standard options influence this command:
AXIS, BORDER, CHARSIZE, COLOUR, JUSTIFY, LINESTYLE, LINEWIDTHThe ColorValues option allows one to plot XYZ data with the Z axis mapped to a color value. For example:
use PDL::Graphics::LUT; ctab(lut_data('idl5')); # set up color palette to 'idl5' points ($x, $y, {ColorValues => $z}); $y = sequence(10)**2+random(10); # Plot blue stars with a solid line through: points $y, {PLOTLINE => 1, COLOUR => BLUE, SYMBOL => STAR}; errbPlot error bars (using "pgerrb()")Usage:
errb ( $y, $yerrors, [$opt] ) errb ( $x, $y, $yerrors, [$opt] ) errb ( $x, $y, $xerrors, $yerrors, [$opt] ) errb ( $x, $y, $xloerr, $xhierr, $yloerr, $yhierr, [$opt])Options recognised:
TERM - Length of terminals in multiples of the default length SYMBOL - Plot the datapoints using the symbol value given, either as name or number - see documentation for 'points'The following standard options influence this command:
AXIS, BORDER, CHARSIZE, COLOUR, JUSTIFY, LINESTYLE, LINEWIDTH $y = sequence(10)**2+random(10); $sigma=0.5*sqrt($y); errb $y, $sigma, {COLOUR => RED, SYMBOL => 18}; contDisplay image as contour map
Usage: cont ( $image, [$contours, $transform, $misval], [$opt] )Notes: $transform for image/cont etc. is used in the same way as the "TR()" array in the underlying PGPLOT FORTRAN routine but is, fortunately, zero-offset. The "transform()" routine can be used to create this piddle. Options recognised:
CONTOURS - A piddle with the contour levels FOLLOW - Follow the contour lines around (uses pgcont rather than pgcons) If this is set >0 the chosen linestyle will be ignored and solid line used for the positive contours and dashed line for the negative contours. LABELS - An array of strings with labels for each contour LABELCOLOUR - The colour of labels if different from the draw colour This will not interfere with the setting of draw colour using the colour keyword. MISSING - The value to ignore for contouring NCONTOURS - The number of contours wanted for automatical creation, overridden by CONTOURS TRANSFORM - The pixel-to-world coordinate transform vectorThe following standard options influence this command:
AXIS, BORDER, COLOUR, JUSTIFY, LINESTYLE, LINEWIDTH $x=sequence(10,10); $ncont = 4; $labels= ['COLD', 'COLDER', 'FREEZING', 'NORWAY'] # This will give four blue contour lines labelled in red. cont $x, {NCONT => $ncont, LABELS => $labels, LABELCOLOR => RED, COLOR => BLUE} binPlot vector as histogram (e.g. "bin(hist($data))")
Usage: bin ( [$x,] $data )Options recognised:
CENTRE - if true, the x values denote the centre of the bin otherwise they give the lower-edge (in x) of the bin CENTER - as CENTREThe following standard options influence this command:
AXIS, BORDER, COLOUR, JUSTIFY, LINESTYLE, LINEWIDTH hi2dPlot image as 2d histogram (not very good IMHO...)
Usage: hi2d ( $image, [$x, $ioff, $bias], [$opt] )Options recognised:
IOFFSET - The offset for each array slice. >0 slants to the right <0 to the left. BIAS - The bias to shift each array slice up by.The following standard options influence this command:
AXIS, BORDER, JUSTIFYNote that meddling with the "ioffset" and "bias" often will require you to change the default plot range somewhat. It is also worth noting that if you have TriD working you will probably be better off using mesh3d or a similar command - see PDL::Graphics::TriD.
$r=sequence(100)/50-1.0; $y=exp(-$r**2)*transpose(exp(-$r**2)) hi2d $y, {IOFF => 1.5, BIAS => 0.07}; arrowPlot an arrow
Usage: arrow($x1, $y1, $x2, $y2, [, $opt]);Plot an arrow from "$x1, $y1" to "$x2, $y2". The arrow shape can be set using the option "Arrow". See the documentation for general options for details about this option (and the example below): Example:
arrow(0, 1, 1, 2, {Arrow => {FS => 1, Angle => 60, Vent => 0.3, Size => 5}});which draws a broad, large arrow from (0, 1) to (1, 2). polyDraw a polygon
Usage: poly ( $x, $y )Options recognised: The following standard options influence this command:
AXIS, BORDER, COLOUR, FILLTYPE, HATCHING, JUSTIFY, LINESTYLE, LINEWIDTH # Fill with hatching in two different colours $x=sequence(10)/10; # First fill with cyan hatching poly $x, $x**2, {COLOR=>5, FILL=>3}; hold; # Then do it over again with the hatching offset in phase: poly $x, $x**2, {COLOR=>6, FILL=>3, HATCH=>{PHASE=>0.5}}; release; circlePlot a circle on the display using the fill setting.
Usage: circle($x, $y, $radius [, $opt]);All arguments can alternatively be given in the options hash using the following options: ellipsePlot an ellipse, optionally using fill style.
Usage: ellipse($x, $y, $a, $b, $theta [, $opt]);All arguments can alternatively be given in the options hash using the following options:
rectangleDraw a rectangle.
Usage: rectangle($xcenter, $ycenter, $xside, $yside, [, $angle, $opt]);This routine draws a rectangle with the chosen fill style. Internally it calls poly which is somewhat slower than "pgrect" but which allows for rotated rectangles as well. The routine recognises the same options as poly and in addition the following
vectDisplay 2 images as a vector field
Usage: vect ( $a, $b, [$scale, $pos, $transform, $misval] )Notes: $transform for image/cont etc. is used in the same way as the "TR()" array in the underlying PGPLOT FORTRAN routine but is, fortunately, zero-offset. The "transform()" routine can be used to create this piddle. This routine will plot a vector field. $a is the horizontal component and $b the vertical component. Options recognised:
SCALE - Set the scale factor for vector lengths. POS - Set the position of vectors. <0 - vector head at coordinate >0 - vector base at coordinate =0 - vector centered on the coordinate TRANSFORM - The pixel-to-world coordinate transform vector MISSING - Elements with this value are ignored.The following standard options influence this command:
ARROW, ARROWSIZE, AXIS, BORDER, CHARSIZE, COLOUR, JUSTIFY, LINESTYLE, LINEWIDTH $a=rvals(11,11,{Centre=>[5,5]}); $b=rvals(11,11,{Centre=>[0,0]}); vect $a, $b, {COLOR=>YELLOW, ARROWSIZE=>0.5, LINESTYLE=>dashed}; transformCreate transform array for contour and image plotting
$win->transform([$xdim,$ydim], $options);This function creates a transform array in the format required by the image and contouring routines. You must call it with the dimensions of your image as arguments or pass these as an anonymous hash - see the example below.
Example:
$im = rvals(100, 100); $w = PDL::Graphics::PGPLOT::Window->new(Device => '/xs'); $t = $w->transform(dims($im), {ImageCenter => 0, Pixinc => 5}); $w->imag($im, {Transform => $t}); tlineThreaded line plotting
$win->tline($x, $y, $options);This is a threaded interface to "line". This is convenient if you have a 2D array and want to plot out every line in one go. The routine will apply any options you apply in a ``reasonable'' way. In the sense that it will loop over the options wrapping over if there are less options than lines. Example:
$h={Colour => ['Red', '1', 4], Linestyle => ['Solid' ,'Dashed']}; $tx=zeroes(100,5)->xlinvals(-5,5); $ty = $tx + $tx->yvals; $win->tline($tx, $ty, $h); tpointsA threaded interface to points
Usage: tpoints($x, $y, $options);This is a threaded interface to "points". This is convenient if you have a 2D array and want to plot out every line in one go. The routine will apply any options you apply in a ``reasonable'' way. In the sense that it will loop over the options wrapping over if there are less options than lines. Example:
$h={Colour => ['Red', '1', 4], Linestyle => ['Solid' ,'Dashed']}; $tx=zeroes(100,5)->xlinvals(-5,5); $ty = $tx + $tx->yvals; tpoints($tx, $ty, $h); Text routinestextWrite text in a plot window at a specified position.
Usage: text ($text, $x, $y [, $opt])Options recognised:
The following standard options influence this command:
COLOUR, CHARSIZE line sequence(10), sequence(10)**2; text 'A parabola', 3, 9, {Justification => 1, Angle=>atan2(6,1)}; legendAdd a legend to a plot
Usage: legend($text, $x, $y, [, $width], $opt]);This function adds a legend to an existing plot. The action is primarily controlled by information in the options hash, and the basic idea is that $x and $y determines the upper left hand corner of the box in which the legend goes. If the width is specified either as an argument or as an option in the option hash this is used to determine the optimal character size to fit the text into part of this width (defaults to 0.5 - see the description of "TextFraction" below). The rest of the width is filled out with either lines or symbols according to the content of the "LineStyle", "Symbol", "Colour" and "LineWidth" options. The local options recognised are as follows:
line $x, $y, {Color => 'Red', LineStyle => 'Solid'}; line $x2, $y2, {Color => 'Blue', 'LineStyle' => 'Dashed', LineWidth => 10}; legend ['A red line', 'A blue line'], 5, 5, {LineStyle => ['Solid', 'Dashed'], Colour => ['Red', 'Blue'] LineWidth => [undef, 10]}; # undef gives default. Cursor routinescursorInteractively read cursor positions.
Usage: ($x, $y, $ch, $xref, $yref) = cursor($opt)This routine has no standard input parameters, but the type of cursor can be set by setting the option "Type" as a key in the anonymous hash $opt. The first three return values from the function are always defined and gives the position selected by the user and the character pressed. Depending on the cursor type selected the last two arguments might also be defined and these give a reference position. For instance if the cursor is selected to be "Rectangle" then the reference position gives one of the corners of the rectangle and $x and $y the diagonally opposite one. Options recognised:
To select a region on a plot, use the rectangle cursor:
($x, $y, $ch, $xref, $yref) = cursor({Type => 'Rectangle'}); poly pdl($x, $xref, $xref, $x, $x), pdl($y, $y, $yref, $yref, $y);To select a region of the X-axis:
($x1, $y1, $ch) = cursor({Type => 'VerticalLine'}); ($x2, $y2, $ch) = cursor({Type => 'TwoVerticalLines', XRef => $x1}); Internal routines_open_new_windowOpen a new window. This sets the window ID, which is the one used when accessing a window later using "pgslct". It also sets the window name to something easily remembered if it has not been set before._setup_windowThis routine sets up a new window with its shape and size. This is also where the two options "WindowXSize" and "WindowYSize" are parsed. These are then forgotten (well, they are stored in $self->{Options}, but forget that) and the corresponding aspect ratio and window width is stored. Alternatively, the "AspectRatio" and "WindowWidth" options are used to set the view surface. The logic goes somewhat like this:
Finally the subpanels are set up using "pgsubp" and colours and linewidth are adjusted according to whether we have a hardcopy device or not. _statusThis routine checks the status of the window. It returns OPEN if the window is open and CLOSED if it is closed._reopenThis functions reopens a window. Since this is an internal function it does not have a lot of error-checking. Make sure the device is closed before calling this routine.There is an unfortunate problem which pops up viz. that the window name cannot be changed at this point since we are offering that to the rest of the world. That might be sensible, but it means that the window name will not reflect the id of the window - use "id()" for that (this is also why we do not call "open_new_window" ) _advance_panelThis routine advances one plot panel, updating the CurrentPanel as well. If the advance will proceed past the page the page will be erased. Also note that when you advance one panel the hold value will be changed._check_move_or_eraseThis routine is a utility routine which checks if we need to move panel, and if so will do this. It also checks if it is necessary to advance panels, and whether they need to be erased._thread_optionsThis function is a cludgy utility function that expands an options hash to an array of hashes looping over options. This is mainly of use for ``threaded'' interfaces to standard plotting routines.optionsAccess the options used when originally opening the window. At the moment this is not updated when the window is changed later.idAccess the window ID that PGPLOT uses for the present window.deviceThis function returns the device type of the present window.nameAccessor to set and examine the name of a window.focusSet focus for subsequent PGPLOT commands to this window.infoGet general information about the PGPLOT environment.
@ans = $self->info( @item );The valid values of @item are as below, where case is not important:
VERSION - What PGPLOT version is in use STATE - The status of the output device, this is returns 'OPEN' if the device is open and 'CLOSED' otherwise. USER - The username of the owner of the spawning program. NOW - The current date and time in the format 'dd-MMM-yyyy hh:mm'. Most people are likely to use Perl functions for this. DEVICE * - The current PGPLOT device or file, see also C<device> FILE * - The filename for the current device TYPE * - And the device type for the current device DEV/TYPE * - This combines DEVICE and TYPE in a form that can be used as input to C<new>. HARDCOPY * - This is flag which is set to 'YES' if the current device is a hardcopy device and 'NO' otherwise. TERMINAL * - This flag is set to 'YES' if the current device is the user's terminal and 'NO' otherwise. CURSOR * - A flag ('YES' or 'NO') to inform whether the current device has a cursor.Those items marced with a "*" only return a valid answer if the window is open. A question mark ("?") is returned if the item is not recognised or the information is not available. _extract_hashThis routine takes and array and returns the first hash reference found as well as those elements that are not hashes. Note the latter point because all other references to hashes in the array will be lost._parse_optionsThis is a convenience routine for parsing a set of options. It returns both the full set of options and those that the user has set._save_statusSaves the PGPLOT state so that changes to settings can be made and then the present state restored by "_restore_status"._restore_statusRestore the PGPLOT state. See _save_status._checkargThis routine checks and optionally alters the arguments given to it._set_colourThis is an internal routine that encapsulates all the nastiness of setting colours depending on the different PGPLOT colour models (although HLS is not supported).The routine works in the following way:
_standard_options_parserThis internal routine is the default routine for parsing options. This routine deals with a subset of options that most routines will accept.INTERNALThe coding tries to follow reasonable standards, so that all functions starting with an underscore should be considered as internal and should not be called from outside the package. In addition most routines has a set of options. These are encapsulated and are not accessible outside the routine. This is to avoid collisions between different variables.AUTHORKarl Glazebrook [kgb@aaoepp.aao.gov.au] modified by Jarle Brinchmann (jarle@astro.ox.ac.uk) who is also responsible for the OO interface, docs mangled by Tuomas J. Lukka (lukka@fas.harvard.edu) and Christian Soeller (c.soeller@auckland.ac.nz). Further contributions and bugfixes from Kaj Wiik, Doug Burke and many others.All rights reserved. There is no warranty. You are allowed to redistribute this software / documentation under certain conditions. For details, see the file COPYING in the PDL distribution. If this file is separated from the PDL distribution, the copyright notice should be included in the file.
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