P followed by number -100 to 100 to alter position. ( 1 unit = line extent/100 ) H followed by number -100 to 100 to alter height. ( 1 unit = line height/100 ) W followed by number -100 to 100 to increase width. ( 1 unit = line extent/100 ) S to plot modified line and return to menu.
Options are: N for no weighting V for weighting by Y value E for weighting by 1/error**2
CUR - indicate continuum regions by cursor. ORD - order of polynomial fit. SIG - factor*sigma on fit for continuum point rejection. ERR - factor*error on point for rejection from continuum fit. ITN - number of iterations for continuum point rejection. FIT - perform the polynomial fitting. GAU - proceed to Gaussian fitting (continuum set).
LIM _ delimit edges of line (default is adjacent continuum edges). SIN - fit a single Gaussian to an indicated line. NEW - introduce a Gaussian at the cursor defined position. NEX - introduce a new Gaussian at the peak. INCH - interactively alter peak position, height or width. LIS - list the Gaussians fitted. SEL - select a line to be modified. DEL - delete a selected Gaussian. OPT - optimize the fit. RECAL - read a previous fit data file and plot this fit. HARD - plot results of fit for hardcopy device. SAVE - save the Gaussian fit spectrum as a file (name prompted for on quitting). CON - move to another section of continuum for more fitting. QUIT - quit from program (spectrum analysis complete).
G A U S S Interactively fits Gaussians to an emission or absorption feature in a spectrum. A spectrum, whose length is prompted for, is plotted on the selected 'SOFT' device together with a residual plot above. Regions of continuum are demarcated with the cursor. Continuum is fitted by a polynomial with rejection of points a selected sigma from this continuum or a fraction of the error bar ( if available ). Single or multiple Gaussian fits are made to the emission/absorption feature. In the case of multiple fits interactive fitting of the profile by Gaussians whose parameters are altered from the terminal occurs. The residuals on the fit ( observed - fitted ) are plotted in the residuals box above the main plot. If error bars are available for the spectrum they are plotted in the residuals box. The fit may be optimized and any single Gaussian parameter can be constrained or its value chained to another. The residuals on the fit for the purposes of the optimization can be weighted either by value or error. Data on the fit - central wavelength, height and sigma - are reported for each Gaussian and r.m.s. and mean fractional error ( if errors available ) on fit. The results may be recorded on a data file. The final fit spectrum can be saved as a file for subsequent analysis. Command parameters - SPECTRUM The data to be fitted. This should be a 1-d .dst file with a .z.data component. If there is a .x.data component this will be used to give the x-axis. If not, the x-axis will just have to be the numbers from 1 to n. XSTART The x-value at which plotting is to start. XEND The x-value at which plotting is to end. (XSTART and XEND are not required if the WHOLE keyword is set.) HIGH The maximum value to be used for the plot. LOW The minimum value to be used for the plot. BIAS Value to be added to zero for the plot. LABEL A label for the plot and the data file. Command keywords - AUTOSCALE The program is to work out the values for HIGH and LOW, using the maximum and minimum values in the data over the specified range. WHOLE The program is to display all of the spectrum. User variables - (">" input, "<" output) (>) SOFT Specifies the device and type to be used for soft plots. See the SOFT command for more details. (>) HARD Specifies the device and type to be used for hard plots. See the HARD command for more details. (<) TVXST is set to the starting x-value for the plot. (<) TVXEN Is set to the final x-value for the plot. (<) TVHIGH Is set to the same value as HIGH. (<) TVLOW Is set to the same value as LOW. (<) TVFILE Is set to the value of SPECTRUM. Subroutines called: MAPSPEC - unmaps the X and Z from virtual memory into arrays in the program MAPSPECE - unmaps the X, Z and error data from virtual memory into arrays in the program MAPSPECG - maps the output fitting spectrum Z component into virtual memory GAUS_XZPLOT - handles all the PGPLOT plotting of spectrum, continuum fit, Gaussian fit, residuals and error bars CONMENU - the continuum fitting menu for polynomial continuum fitting GAUMENU - the Gaussian fitting menu for all Gaussian fitting JRW / AAO March 1987
FIGARO A general data reduction system