B List of Commands

! n
Runs command number n from the command history. See help on COMMS command.

ADD entry
Adds the current polarization spectrum to the specified stack entry. See notes on the SUBTRACT command for more details.

ARROWSTYLE fs angle vent
Sets the style of the arrowheads to be drawn by QUPLOT when QUARROW is set. fs=1 (filled arrowhead). fs=2 (outline). The angle denoted the acute angle of the arrow point in degrees. Vent is the fraction of the triangular arrowhead that is cut away from the back.

BIN entry error
Bins the specified stack entry so that each wavelength bin has a constant error in percentage polarization.

BOX
Flags the graphics screen to clear before each triplot.

CADD q u
Adds the constant polarization vector (q,u) to the currect arrays. q and u should be in % polarization.

CHOPW min max
Reduces the wavelength range of the current polarization spectrum to run from min to max.

CIRANGE
Sets the intensity plotting range interactively.

COMFILE filename
This command tells polmap to use a command file as input instead of the terminal.

CPFRANGE
Sets the polarized flux plotting range interactively.

CPRANGE
Sets the percentage polarization plotting range interactively.

COMMS
List the twenty previous commands issued.

CONTADD entry
Adds the current (I,Q,U) spectrum to the specified stack entry.

CONTDEF [min max] [min max]
Defines continuum regions of the polarization spectrum. Multiple continuum bins may be defined on one command line. If no parameters are given then the continuum bins are defined using the cursor. A triplot must have previously been plotted in order to interactively define windows. In order to quit contdef define a bin with max less than min.

CONTFIT entry order
Make a polynomial fit to the continuum of a polarization spectrum. The continuum is defined using bins set up by CONTDEF. A polynomial fit is made to the Stokes vector (I,Q,U). The resulting fit is stored in the current arrays.

CONTSUB entry
Subtracts the current (I,Q,U) spectrum from the specified stack entry. This command can be used to remove polarized continuum counts from a polarization spectrum.

COUNTS
Finds the mean value of the I stokes parameter using all the bins in the current polarization spectrum.

CREMOVE
Uses the cursor to set two (wavelength,intensity) points. The parts of the current spectrum with wavelengths outside the range defined are lost. An intensity i (found by linear interpolation between the two points) is subtracted from each of the remaining intensities. This command is useful for removing the effects of a depolaring continuum from an emission line, for example.

CROT
Sets the plotting colour for the line to change after each plot

CSUB q u
Subtracts the constant polarization vector (q,u) from the currect arrays. q and u should be % polarization.

CTRANGE
Sets the PA plotting range interactively.

CURSOR
Use the graphics cursor to measure points on the current plot.

CWRANGE
Define the plotting wavelength range using the cursor. A triplot must have previously been made.

DEL entry [entry]
Deletes the specified entries from the stack.

DEV device [nx] [ny]
Initialize the plotting device. The device name must be a GKS standard. Use a question mark as the parameter in order to list the possible devices. The plotting surface is divided into nx subdivisions in x and ny subdivisions in y. If nx and ny are not specified then the default values are used (nx=1 and ny=1).

DRAWLINE x1 y1 x2 y2
This command draws a line in the current line style from point (x1,y1) to (x2,y2), where the distances are given in world coordinates.

EDIT [wmin] [wmax]
Removes the data points from the current spectrum that lie between wmin and wmax.If wmin and wmax are not specified the cursor is used to specify the wavelength range.

FITPA pa ncoeffs
Given the actual pa of the current spectrum a polynomial fit of ncoeff coefficients is made to the difference between the actual and observed position angles as a function of wavelength. This fit can then be applied to another observation using PACALIB.

FONT type
Sets the character font for plotting. There are four fonts: 1. Simple single-stroke (default) 2. Roman font 3. Italic font 4. Script font

GET entry
Takes the polarization spectrum from the stack and places it in the current arrays.

HELP command
Gives online help to polmap commands. HELP COMMANDS will give a list of all the possible commands. HELP <command> will provide detailed online help for the selected command. Parameters shown in brackets are optional.

HIST
Flags triplot to produce histogram style output.

IAUTO
Automatically set the Stokes I range.

ICADD constant
Adds a constant to the Stokes I array of the current polarization spectrum.

ILABEL
Sets the label for the intensity on a triplot.

INTEG
Integrates the Stokes I parameter of the current array using trapezoidal integration.

IPLOT
Plots the Stokes I parameter of the current spectrum.

IQUADD i q u
Adds the constant polarization vector (i,q,u) to the current arrays.

IRANGE min max
Limits the Stokes I plotting range.

ISFIT
Fits a Serkowski law to the data held in the current arrays. Non-linear least-squares minimization is used. The resulting IS law is mapped onto the X array of the current polarization spectrum.

LIST [mode]
List the stack contents. If mode is 0 then the contents of the current arrays are listed.

LROT
Flags the line style to change after every plot with nobox set.

LS
List the polarization spectra titles that are on the current stack in ’page’ format, useful for large stacks.

MARK
Flags triplot to mark bins with points and error bars rather than in histogram style (HIST) or join-the-dots style (POLY).

MAXPOL
This command finds the maximum polarization datum within each of the continuum bins.

MERGE entry
Merges the current polarization spectrum with the spectrum in the specified stack entry. The resulting spectrum is sorted into wavelength order. Weighted means for the polarization vector are calculated for bins of identical X value.

MOTD
Displays the message of the day

NOBOX
Stops automatic clearing of the plotting surface before a triplot.

NOCROT
Sets the line ploot colour to the forground colour.

NOLROT
Stops the line style changing.

NOPFLUX
Don’t include polarized flux box in triplot.

NOQUARROW
Stops the QUPLOT command joining the dots with arrows.

NOQUJOIN
Data are plotted as points in the QU plane.

NOQUPANEL
Switches TRIPLOT back to its default mode of plotting.

PACALIB
Applies a position angle fit (previously made using FITPA) to the current spectrum. This command is usually used to remove the rotation of pa with wavelength associated with achromatic half-wave plates.

PAGE
Clears the graphics screen and moves on to a new page.

PAPER width height
Sets the physical size of the plotting windows. Width and height must be in cms and a call to DEV must have been made immediately before.

PFLUX
Incude polarized flux box in triplot.

PFRANGE min max
Limits the polarized flux plotting range.

POLY
Forces join-the-dots plotting rather than histogram plotting.

POP entry
Same as GET (qv).

PPLOT
Plots the polarization spectrum of the current arrays.

PRANGE min max
Limits the percentage polarization plotting range.

PTHETA
Sums the Stokes parameters over each of the pre-defined continuum bins and display the results.

PUSH
Same as PUT (qv).

PUT
Places the current polarization spectrum on to the top of the stack. If the stack is too large a warning message is given.

PVAL number value
Sets the value of a specified IS parameter to the value

QAUTO
Automatically set the Stokes Q range.

QRANGE min max
Limits the Stokes Q plotting range.

QSM width
Convolves the current spectrum with a Gaussian profile of the given width. Intensities beyond the ends of the arrays are assumed to be zero.

QUARROW
Forces QUPLOT to join-the-dots using arrows. The style of the arrowhead may be altered using ARROWSTYLE.

QUIT
Quits the polmap program.

QUJOIN
Forces points to be joined by a dotted line in the QU plane.

QUPANEL
Flag the TRIPLOT command to plot Stokes I, Q and U rather than the usual I, P and PA.

QUPLOT error
Plots the data in the current arrays in the QU plane. The data is binned to the constant error given. The wavelength range of the data to be plotted can set using WRANGE. The axes of the plot can be adjusted using QRANGE and URANGE. The data are plotted with error bars and consecutive points can be joined by setting the QUJOIN flag.

RDALAS filename
Reads in a polarization spectrum from the file filename. The file must be in ascii format. The first column must be the wavelength followed by the Stokes Q parameter and its variance and the Stokes U parameter and its variance. The polarization spectrum is placed in the current arrays.

RDSTK filename
Reads a stack into polmap.

RDTSP filename
Reads in a polarization spectrum from a TSP (Bailey 1992) format file. Details of the N-dimensional data format files can be found in the TSP user guide. The polarization spectrum is placed in the current arrays.

REGRID binsize
Rebins the current polarization spectrum. Each bin in the results spectrum corresponds to binsize bins in the old spectrum.

RETITLE entry
Retitle the specified stack entry. The retitle command will prompt for the new title.

ROTPA angle
Rotates the position angle of the current polarization spectrum through angle where the angle is given in degrees.

RVEL vel
Applies the given radial velocity correction to the wavelength arrays of the current polarization spectrum. The standard sign convention is used in which a positive velocity indicates the source is moving away from the observer.

SERKTHRU q u lambda k lammax
This command maps a Serkowski law onto the current arrays. The vector (q,u) at wavelength lambda is given along with the values ok k and lammax. The Serkowski law that passes through this point is mapped on the current arrays.

SETCOLOUR colour
Sets the line colour for a triplot.

SETHEIGHT height
Sets the height of the characters that are plotted. Standard size is height=1.

SETLINE linestyle
Sets the line style of a triplot. The parameter sould be in the range 1-5.

SETSYMB style
Sets the symbol style for a QU plot. The style parameter should be in the range 0 to 31.

SMOOTH n
Applies a box smooth to the current polarization spectrum (Bevington routine). The smooth is repeated n times.

STATADD
Adds the mean polarization vector obtained from the results of the most recent PTHETA to the currect arrays.

STATSUB
Subtracts the mean polarization vector obtained from the results of the most recent PTHETA to the currect arrays.

SUBTRACT entry
Subtract the current polarization from a specified stack entry. The Stokes Q and U parameters of both spectra are normalised and the current polarization vector is subtracted from the specified stack entry. The Stokes I parameter is obtained from the stack polarization spectrum. Linear interpolation is used to regrid the stack polarization spectrum onto the current wavelength grid.

SWAP entry
Swaps the current polarization spectrum with that of a stack entry.

TAPPEND string
Appends the character string string to the end to the current polarization spectrum title.

TAUTO
Switchs the position angle plotting range to (0,180).

TEXT [x] [y]
This command can be used to annotate diagrams. The x and y axis positions for the lefthand end of the text may be given. The angle at which the text is to be written is then prompted for. Finally the text string is prompted for. The text is written in the current font style. If x and y are not given on the command line the cursor is used to locate the position of the text.

TFREE
Releases PA plotting restrictions set using THI and TLOW.

THI
PA data in the range 0 to (Tmax-180) is plotted above 180. This avoids messy plots that can be obtained if the PA of the polarization spectrum is close to 0 or 180. eg. >TRANGE 0 190,THI will plot all PAs between 0 and 10 between 180 and 190.

TITLE title
Titles the current polarization spectrum with the character string title. Quotes are usually required to protect the case and numerics.

TLOW
PA data in the range (180+Tmin) to 180is plotted below 0. This avoids messy plots that can be obtained if the PA of the polarization spectrum is close to 0 or 180. eg TRANGE -10 180,TLOW will plot all PAs between 170 and 180 between -10 and 0.

TOV wavelength
Transforms the x-axis of the current polarization spectrum to velocity space. The wavelength given is the rest wavelength for the transformation and the velocity is in kilometers per second.

TOW wavelength
Transforms the x-axis of the current polarization spectrum to wavelength space. The parameter is the wavelength of the rest velocity for the transformation and should be given in Angstroms.

TRANGE min max
Limits the position angle plotting range.

TRIPLOT error [entry] [entry] ...
Plot the specified polarization spectra in triplot format. This format has the position angle in the top section, the percentage polarization in the middle section and the bottom section displays the I Stokes parameter. The polarization is binned to a constant error. The DEV command must have been called to initialize the plotting device. If no entry is specified the contents of the current arrays are plotted.

UAUTO
Automatically set the Stokes U range.

URANGE min max
Limits the Stokes U plotting range.

WAUTO
Automatically set the wavelength range.

WMERGE spec1 spec2 weight1 weight2
Merges two polarization spectra with identical x-grids. The spectra are merged according to the given weights and the result is placed in the current arrays.

WRALAS filename
Writes out the polarization spectrum from the current arrays into the file filename. The file is written in ascii format with wavelength as the first column followed by the Q Stokes parameter and its variance and the U Stokes parameter and its variance.

WRANGE min max
Limits the wavelength plotting range.

WRTSP filename
Writes out the polarization spectrum from the current arrays into a TSP format file. Details of the N-dimensional data format files can be found in the TSP user guide.

WRSTK filename
Writes out the stack into a save file.

XADD constant
Adds a constant value to the x array.

XGRID xstart xend npts
Creates an evenly spaced wavelength grid on the current arrays. The Stokes parameters are zeroed and the current spectrum is lost. The grid has npts and runs from xstart to xend.

XLABEL label
Sets the x-axis label for the triplot.