; XGAUS ;--------------------------------------------------------------- ;! Fits 1-dimensional Gaussians to images ;# TASK ANALYSIS PLOT SPECTRAL ONED MODELING TV-APPL ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 2005, 2008 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- ;--------------------------------------------------------------- XGAUS LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC XGAUS Fits 1-dimensional Gaussians to images INNAME Input image name (name) INCLASS Input image name (class) INSEQ 0.0 9999.0 Input image name (seq. #) INDISK 0.0 9.0 Input image disk unit # OUTNAME Output image name (name) OUTCLASS Output image name (class) OUTSEQ -1.0 9999.0 Output image name (seq. #) OUTDISK 0.0 9.0 Output image disk unit #. BLC Bottom left corner of input TRC Top right corner of input YINC 0.0 128.0 Do every YINCth row ZINC 0.0 128.0 Do every ZINCth plane FLUX 0.0 Flux cutoff (see HELP) BCHAN -1.0 512.0 # channels at left for baseline (-1 => no baseline) ECHAN -1.0 512.0 # channels at right for baseline (0 => none) DOOUTPUT -1.0 1.0 Write residual image DOSLICE -1.0 2.0 Plot data on TEK/TV DOMODEL -1.0 1.0 Plot model on TEK/TV DORESID -1.0 1.0 Plot residuals on TEK/TV PIXRANGE Min,Max of image intensity Max <= Min => entire range LTYPE 0.0 6.0 Type of labeling: 1 border, 2 no ticks, 3 standard, 4 rel to center, 5 rel to subim cen 6 map pixels PIXVAL 0.0 Display if peak < PIXVAL NITER 0.0 4000.0 Max # fit iterations 0 -> 100. NGAUSS 1.0 4.0 Number of Gaussians Guess of model parameters GMAX 0.0 Peak of component (JY) GPOS X position (pixels wrt the reference pixel) GWIDTH 0.0 FWHM of comp. (pixels) Solve for model parameters? DOMAX -1.0 1.0 Solve for GMAX? DOPOS -1.0 1.0 Solve for GPOS? DOWIDTH -1.0 1.0 Solve for GWIDTH? DOTV -1.0 1.0 > 0 use TV instead of TEK GRCHAN 0.0 7.0 TV graphics channel to use BADDISK Disk to avoid for scratch ---------------------------------------------------------------- XGAUS Task: Fits one-dimensional Gaussians to each row of an image. (Normally XGAUS will be used on images with frequency or velocity as the first axis, but it will procede with others as well.) The task fits up to 4 Gaussians plus a linear baseline to each row and writes up to 4 + 8*NGAUSS n-1 dimensional images containing the fit parameters and their uncertainties. Optionally, it will write the residual image as well. With a careful choice of input parameters, the task is capable of running in a batch-like mode. However, particularly for NGAUSS > 1, an interactive mode (using the TEK graphics terminal or the TV graphics planes) is recommended. Note that, since the TV and TEK are not allowed in BATCH jobs, XGAUS turns off all interactive options and TEK/TV displays when it is run in batch. We strongly recommend beginning with DOTV=1 (the Tek crosshairs have trouble), GRCHAN=0 (use color to differentiate what is plotted), DOSLICE=2 (allow initial guesses to be set), DOMODEL=1 (see what was fit). The initial guess uses channels 1-BCHAN and Nchan to Nchan-ECHAN+1 to set the DC level and slope. It is plotted as X signs. The data are plotted with stepped connecting lines, the fit as a smooth connecting line, and the residual as a dashed line. With GRCHAN=0, the guess is in graphics channel 2 (usually green), the data in 1 (usually yellow), the fit in 4 (usually cyan), and the residual in 3 (usually pink). Adverbs: INNAME.....Input image name (name). Standard defaults. INCLASS....Input image name (class). Standard defaults. INSEQ......Input image name (seq. #). 0 => highest. INDISK.....Disk drive # of input image. 0 => any. OUTNAME....Output image name (name). Standard defaults. OUTCLASS...Output image name (class). Standard defaults. Used only for the residual image. The OUTCLASSes for the fit parameters are SLOPE, CONST, AMPLn, CENTRn, and WIDTHn and for the uncertainties are DSLOPE, DCONST, DAMPLn, DCENTn, and DWIDTn. The "flux" of each component (ampl * width * 1.06) is written with OUTCLASSes of FLUXn and DFLUXn. OUTSEQ.....Output image name (seq. #). 0 => highest unique. OUTDISK....Disk drive # of output image. 0 => highest number with sufficient space. BLC........Bottom right corner in input image of desired subimage. Default is entire image. TRC........Top right corner in input image of desired subimage. Default is entire image. YINC.......Do only every YINC'th row (beginning at BLC(2)). ZINC.......Do only every ZINC'th plane (beginning at BLC(3)). FLUX.......A flux cutoff in the same units as the input image (i.e. Jy/beam). If a row does not have three consecutive points above this level, no component is fit to the row. It is also used to limit the points which determine the initial guess. BCHAN......Number of points at the left edge of the input row used to determine the initial guess for the linear baseline. -1 => do not fit a baseline. 0 => no channels at the left, i.e. the initial guess for the baseline slope will be zero. ECHAN......Number of points at the right edge of the input row used to determine the initial guess for baseline. 0 => no channels at the right, i.e. the initial guess for the baseline slope will be zero. DOOUTPUT...True (> 0) requests that the residual (data-model) map be catalogued (using OUTCLASS). DOSLICE....True (> 0) implies plot the data on the TEK or TV. > 1 also requests a TEK/TV plot of the initial guess. It must be set > 1. if you wish the option to correct initial guesses with the TEK cross hairs or TV cursor. If DOSLICE > 1 and NGAUSS > 1, the program pauses after plotting its initial guess and requests user input from the terminal. Hit RETURN to procede with the program's initial guess. Enter BAD to have the solution for the row blanked and E to have the program request your guidance as to a better initial guess. During the entering of a new initial guess with the TEK crosshairs or TV cursor, you may request that a particular component be null (held at 0 amplitude) by indicating that its peak or halfwidth point is outside the plot area. DOMODEL....True (> 0) requests a plot of the final model for each row on the TEK/TV. DORESID....True (> 0) requests a plot of the final residual values in each row. If any one or more of DOSLICE, DOMODEL, or DORESID is true, then the program will pause after each row and request input from the terminal. At that point, you may enter BAD to have the solution blanked or simply a RETURN to keep the answer. The program will warn you if any of the fit parameters are way out of normal limits. For NGAUSS > 1, one may also enter RETR to loop back and try again with a manually entered initial guess. PIXRANGE...Min,Max of Image intensity. 0,0 => min,max of EACH row (separately). LTYPE......Labelling type: 1 = border, 2 = no ticks, 3 = standard, 4 = relative to center of row, 5 = relative to subimage (BLC, TRC) center 6 = pixels in original map PIXVAL.....Plot row only if the peak value < PIXVAL. Limits the plots to those of uncertain intensities. NITER......Maximum function evaluations during the fit of each row. (< 10 -> 100 for NGAUSS > 1, < 100 -> 150 for 1 Gaussian) NGAUSS.....Number of Gaussians to fit (between 1 and 4). GMAX.......Estimate of brightness of components 1 through 4. 0 => use data at GPOS. Ignored if NGAUSS = 1. GPOS.......Estimate of central pixel of comps 1 through 4 in pixels from the reference pixel (increases to the right). Ignored if NGAUSS = 1. GWIDTH.....Estimate of the FWHM in pixels of comps 1 - 4. Ignored if NGAUSS = 1. If NGAUSS > 1, the program will use either the user initial guess or the previous solution as the new initial guess - whichever has a lower rms. To indicate that the program should always use the previous solution, set all GWIDTH to 0. Of course, you may always enter a revised initial guess with the TEK/TV. DOMAX......<= 0. means hold this parm fixed (NGAUSS > 1 only). DOPOS......<= 0. means hold this parm fixed (NGAUSS > 1 only). DOWIDTH....<= 0. means hold this parm fixed (NGAUSS > 1 only). DOTV.......> 0 => use TV, otherwise the TEK emulator is used. This emulator sometimes does not work well on LInux systems. GRCHAN.....TV graphics channel to use. 0 -> use more than one to allow color to contain extra meaning. BADDISK....Disk drives to avoid for scratch files. ----------------------------------------------------------------