mktrace¶
Refine a STIS trace table.
- A trace is generated from the science file and a trace center is computed.
- The two traces bracketing the trace center are extracted from the trace table and interpolated
- The correction is computed as the difference between the linear fit to the science and interpolated traces
- The correction is applied to all traces in the trace file for that particular OPT_ELEM and CENWAVE
- A new trace table is written to the current directory and the relevant keywords are updates in the header of the input file.
Examples¶
Simple example of running mktrace on a STIS file named 'file.fits':
>>> import mktrace
>>> mktrace.mktrace('file.fits', [tracecen=509.4], [weights=[(x1,x2),(x3,x4)])
Authors: |
---|
- Author (IDL): Linda Dressel
- Python version: Nadia Dencheva
-
class
stistools.mktrace.
Trace
(file, kwinfo)¶ Trace class for a crj or flt file.
Notes
tr=Trace(file) file is a crj or flt file.
opt_elem, cenwave, sporder are read from the header of the science file a2center is a2center of the trace generated from the science file
tr_ind= tr.getTraceInd(a2center)
tr_ind is the index of the row in the trace file which brackets from below a2center as computed fro the generated trace
tr.readTrace(tr_ind)
a2center = tr.generateTrace(...)
Methods
gFitTrace
(specimage, y1, y2)Fit a gaussian to each column of an image. generateTrace
(data, kwinfo[, tracecen, wind])Generates a trace from a science file. getTraceInd
(a2center)Finds the first trace in the trace table whose A2CENTER is larger than the specified a2center. openTraceFile
(filename)Returns a spectrum trace table readTrace
(tr_ind)reads the specified row from the 1dttab.fits writeTrace
(fname, sciline, refline, ...)The 'writeTrace' method performs the following steps: -
gFitTrace
(specimage, y1, y2)¶ Fit a gaussian to each column of an image.
-
generateTrace
(data, kwinfo, tracecen=0.0, wind=None)¶ Generates a trace from a science file.
-
getTraceInd
(a2center)¶ Finds the first trace in the trace table whose A2CENTER is larger than the specified a2center.
-
openTraceFile
(filename)¶ Returns a spectrum trace table
-
readTrace
(tr_ind)¶ reads the specified row from the 1dttab.fits
-
writeTrace
(fname, sciline, refline, interp_trace, trace1024, tr_ind, a2disp_ind)¶ The 'writeTrace' method performs the following steps:
- Adds sciline-refline to all traces with the relevent OPT_ELEM, CENWAVE and SPORDER.
- Writes the new trace table to the current directory.
- Updates the SPTRCTAB keyword in the header to point to the new table.
- Writes out fits files with the
- science trace - '_sci'
- the fit to the science trace - '_scifit'
- the interpolated trace - '_interp'
- the linear fit to the interpolated trace - '_interpfit'
-
-
stistools.mktrace.
interp
(y, n)¶ Given a 1D array of size m, interpolates it to a size n (m < n).
-
stistools.mktrace.
mktrace
(fname, tracecen=0.0, weights=None)¶ Refine a stis spectroscopic trace.