source: trunk/docs/app-param.tex @ 167

Last change on this file since 167 was 162, checked in by Matthew Whiting, 18 years ago

Editing of Guide. Mostly minor, with one new parameter added (beamSize).

File size: 9.4 KB
Line 
1\secA{Available parameters}
2\label{app-param}
3
4The full list of parameters that can be listed in the input file are
5given here. If not listed, they take the default value given in
6parentheses. Since the order of the parameters in the input file does
7not matter, they are grouped here in logical sections.
8
9\secB*{Input-output related}
10\begin{entry}
11\item[ImageFile (no default assumed)] The filename of the
12  data cube to be analysed.
13\item[flagSubsection \texttt{[false]}] A flag to indicate whether one
14  wants a subsection of the requested image.
15\item[Subsection \texttt{[ [*,*,*] ]}] The requested subsection, which
16  should be specified in the format \texttt{[x1:x2,y1:y2,z1:z2]},
17  where the limits are inclusive. If the full range of a dimension is
18  required, use a \texttt{*}, \eg if you want the full spectral range
19  of a subsection of the image, use \texttt{[30:140,30:140,*]} (thus
20  the default is the full cube).
21\item[flagReconExists \texttt{[false]}] A flag to indicate whether the
22  reconstructed array has been saved by a previous run of \duchamp. If
23  set true, the reconstructed array will be read from the file given
24  by \texttt{reconFile}, rather than calculated directly.
25\item[reconFile (no default assumed)] The FITS file that contains the
26  reconstructed array. If \texttt{flagReconExists} is true and this
27  parameter is not defined, the default file searched will be
28  determined by the \atrous\ parameters (see \S\ref{sec-recon}).
29\item[OutFile \texttt{[duchamp-Results.txt]}] The file containing the
30  final list of detections. This also records the list of input
31  parameters.
32\item[SpectraFile \texttt{[duchamp-Spectra.ps]}] The postscript file
33  containing the resulting integrated spectra and images of the
34  detections.
35\item[flagLog \texttt{[true]}] A flag to indicate whether intermediate
36  detections should be logged.
37\item[LogFile \texttt{[duchamp-Logfile.txt]}] The file in which
38  intermediate detections are logged. These are detections that have
39  not been merged. This is primarily for use in debugging and
40  diagnostic purposes -- normal use of the program will probably not
41  require this.
42\item[flagOutputRecon \texttt{[false]}] A flag to say whether or not
43  to save the reconstructed cube as a FITS file. The filename will be
44  derived according to the naming scheme detailed in
45  Section~\ref{sec-reconIO}.
46\item[flagOutputResid \texttt{[false]}] As for
47  \texttt{flagOutputRecon}, but for the residual array -- the
48  difference between the original cube and the reconstructed cube. The
49  filename will be derived according to the naming scheme detailed in
50  Section~\ref{sec-reconIO}.
51\item[flagVOT \texttt{[false]}] A flag to say whether to create a
52  VOTable file corresponding to the information in
53  \texttt{outfile}. This will be an XML file in the Virtual
54  Observatory VOTable format.
55\item[votFile \texttt{[duchamp-Results.xml]}] The VOTable file with
56  the list of final detections. Some input parameters are also
57  recorded.
58\item[flagKarma \texttt{[false]}] A flag to say whether to create a
59  Karma annotation file corresponding to the information in
60  \texttt{outfile}. This can be used as an overlay for the Karma
61  programs such as \texttt{kvis}.
62\item[karmaFile \texttt{[duchamp-Results.ann]}] The Karma annotation
63  file showing the list of final detections.
64\item[flagMaps \texttt{[true]}] A flag to say whether to save
65  postscript files showing the 0th moment map of the whole cube
66  (parameter \texttt{momentMap}) and the detection image
67  (\texttt{detectionMap}).
68\item[momentMap \texttt{[duchamp-MomentMap.ps]}] A postscript file
69  containing a map of the 0th moment of the detected sources, as well
70  as pixel and WCS coordinates.
71\item[detectionMap \texttt{[duchamp-DetectionMap.ps]}] A postscript
72  file showing each of the detected objects, coloured in greyscale by
73  the number of channels spanned by each pixel. Also shows pixel and
74  WCS coordinates.
75\end{entry}
76
77\secB*{Modifying the cube}
78\begin{entry}
79\item[flagBlankPix \texttt{[true]}] A flag to say whether to remove
80  BLANK pixels from the analysis -- these are pixels set to some
81  particular value because they fall outside the imaged area.
82\item[blankPixValue \texttt{[-8.00061]}] The value of the BLANK
83  pixels, if this information is not contained in the FITS header (the
84  usual procedure is to obtain this value from the header information
85  -- in which case the value set by this parameter is ignored).
86\item[flagMW \texttt{[false]}] A flag to say whether to ignore
87  channels contaminated by Milky Way (or other) emission -- the
88  searching algorithms will not look at these channels.
89\item[maxMW \texttt{[112]}] The maximum channel number containing
90  ``Milky Way'' emission.
91\item[minMW \texttt{[75]}] The minimum channel number containing
92  ``Milky Way'' emission. Note that the range specified by
93  \texttt{maxMW} and \texttt{minMW} is inclusive.
94\item[flagBaseline \texttt{[false]}] A flag to say whether to remove
95  the baseline from each spectrum in the cube for the purposes of
96  reconstruction and detection.
97\end{entry}
98
99\secB*{Detection related}
100
101\secC*{General detection}
102\begin{entry}
103\item[flagNegative \texttt{[false]}] A flag to indicate that the
104  features being searched for are negative. The cube will be inverted
105  prior to searching.
106\item[snrCut \texttt{[3.]}] The cut-off value for thresholding, in
107  terms of number of $\sigma$ above the mean.
108\item[flagGrowth \texttt{[false]}] A flag indicating whether or not to
109  grow the detected objects to a smaller threshold.
110\item[growthCut \texttt{[2.]}] The smaller threshold using in growing
111  detections. In units of $\sigma$ above the mean.
112\item[beamSize \texttt{[10.]}] The size of the beam in pixels. If the
113  header keywords BMAJ and BMIN are present, then these will be used
114  to calculate the beam size, and this parameter will be ignored.
115\end{entry}
116
117\secC*{\Atrous\ reconstruction}
118\begin{entry}
119\item [flagATrous \texttt{[true]}] A flag indicating whether or not to
120  reconstruct the cube using the \atrous\ wavelet
121  reconstruction. See \S\ref{sec-recon} for details.
122\item[reconDim \texttt{[3]}] The number of dimensions to use in the
123  reconstruction. 1 means reconstruct each spectrum separately, 2
124  means each channel map is done separately, and 3 means do the whole
125  cube in one go.
126\item[scaleMin \texttt{[1]}] The minimum wavelet scale to be used in the
127  reconstruction. A value of 1 means ``use all scales''.
128\item[snrRecon \texttt{[4]}] The thresholding cutoff used in the
129  reconstruction -- only wavelet coefficients this many $\sigma$ above
130  the mean (or greater) are included in the reconstruction.
131\item[filterCode \texttt{[1]}] The code number of the filter to use in
132  the reconstruction. The options are:
133  \begin{itemize}
134  \item \textbf{1:} B$_3$-spline filter: coefficients =
135    $(\frac{1}{16}, \frac{1}{4}, \frac{3}{8}, \frac{1}{4}, \frac{1}{16})$
136  \item \textbf{2:} Triangle filter: coefficients =
137    $(\frac{1}{4}, \frac{1}{2}, \frac{1}{4})$
138  \item \textbf{3:} Haar wavelet: coefficients =
139    $(0, \frac{1}{2}, \frac{1}{2})$
140  \end{itemize}
141\end{entry}
142
143\secC*{FDR method}
144\begin{entry}
145\item[flagFDR \texttt{[false]}] A flag indicating whether or not to use
146  the False Discovery Rate method in thresholding the pixels.
147\item[alphaFDR \texttt{[0.01]}] The $\alpha$ parameter used in the FDR
148analysis. The average number of false detections, as a fraction of the
149total number, will be less than $\alpha$ (see \S\ref{sec-detection}).
150\end{entry}
151
152\secC*{Merging detections}
153\begin{entry}
154\item[minPix \texttt{[2]}] The minimum number of spatial pixels for a
155  single detection to be counted.
156\item[minChannels \texttt{[3]}] The minimum number of consecutive
157  channels that must be present in a detection.
158\item[flagAdjacent \texttt{[true]}] A flag indicating whether to use
159  the ``adjacent pixel'' criterion to decide whether to merge
160  objects. If not, the next two parameters are used to determine
161  whether objects are within the necessary thresholds.
162\item[threshSpatial \texttt{[3.]}] The maximum allowed minimum spatial
163  separation (in pixels) between two detections for them to be merged
164  into one. Only used if \texttt{flagAdjacent = false}.
165\item[threshVelocity \texttt{[7.]}] The maximum allowed minimum channel
166  separation between two detections for them to be merged into
167  one.
168\end{entry}
169
170\secC*{Other parameters}
171\begin{entry}
172\item[spectralMethod \texttt{[peak]}] This indicates which method is used
173  to plot the output spectra: \texttt{peak} means plot the spectrum
174  containing the detection's peak pixel; \texttt{sum} means sum the
175  spectra of each detected spatial pixel, and correct for the beam
176  size. Any other choice defaults to \texttt{peak}.
177\item[spectralUnits \texttt{[km/s]}] The user can specify the units of
178  the spectral axis. Assuming the WCS of the FITS file is valid, the
179  spectral axis is transformed into velocity, and put into these units
180  for all output and for calculations such as the integrated flux of a
181  detection.
182\item[drawBorders \texttt{[true]}] A flag indicating whether borders
183  are to be drawn around the detected objects in the moment maps
184  included in the output (see for example Fig.~\ref{fig-spect}).
185\item[drawBlankEdges \texttt{[true]}] A flag indicating whether to
186 draw the dividing line between BLANK and non-BLANK pixels on the
187 2-dimensional images (see for example Fig.~\ref{fig-moment}).
188\item[verbose \texttt{[true]}] A flag indicating whether to print the
189  progress of computationally-intensive algorithms (such as the
190  searching and merging) to screen.
191\end{entry}
192
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