TWEAKUTILS: Utility Functions for TWEAKREG
The functions in this module support the various aspects of TweakReg
,
including finding the objects in the images and plotting the residuals.
- Authors:
Warren Hack
- License:
- drizzlepac.tweakutils.build_pos_grid(start, end, nstep, mesh=False)[source]
Deprecated since version 3.0.0: The build_pos_grid function is deprecated and may be removed in a future version.
Return a grid of positions starting at X,Y given by ‘start’, and ending at X,Y given by ‘end’. The grid will be completely filled in X and Y by every ‘step’ interval.
- drizzlepac.tweakutils.build_xy_zeropoint(imgxy, refxy, searchrad=3.0, histplot=False, figure_id=1, plotname=None, interactive=True)[source]
Deprecated since version 3.0.0: The build_xy_zeropoint function is deprecated and may be removed in a future version.
- Create a matrix which contains the delta between each XY position and
each UV position.
- drizzlepac.tweakutils.createWcsHDU(wcs)[source]
Generate a WCS header object that can be used to populate a reference WCS HDU.
For most applications, stwcs.wcsutil.HSTWCS.wcs2header() will work just as well.
- drizzlepac.tweakutils.find_xy_peak(img, center=None, sigma=3.0)[source]
Deprecated since version 3.0.0: The find_xy_peak function is deprecated and may be removed in a future version.
Find the center of the peak of offsets
- drizzlepac.tweakutils.gauss(x, sigma)[source]
Compute 1-D value of gaussian at position x relative to center.
- drizzlepac.tweakutils.gauss_array(nx, ny=None, fwhm=1.0, sigma_x=None, sigma_y=None, zero_norm=False)[source]
Computes the 2D Gaussian with size nx*ny.
- Parameters:
- nxint
- nyint [Default: None]
Size of output array for the generated Gaussian. If ny == None, output will be an array nx X nx pixels.
- fwhmfloat [Default: 1.0]
Full-width, half-maximum of the Gaussian to be generated
- sigma_xfloat [Default: None]
- sigma_yfloat [Default: None]
Sigma_x and sigma_y are the stddev of the Gaussian functions.
- zero_normbool [Default: False]
The kernel will be normalized to a sum of 1 when True.
- Returns:
- gauss_arrarray
A numpy array with the generated gaussian function
- drizzlepac.tweakutils.idlgauss_convolve(image, fwhm)[source]
Deprecated since version 3.0.0: The idlgauss_convolve function is deprecated and may be removed in a future version.
- drizzlepac.tweakutils.isfloat(value)[source]
Return True if all characters are part of a floating point value
- drizzlepac.tweakutils.make_vector_plot(coordfile, columns=[1, 2, 3, 4], data=None, figure_id=None, title=None, axes=None, every=1, labelsize=8, ylimit=None, limit=None, xlower=None, ylower=None, output=None, headl=4, headw=3, xsh=0.0, ysh=0.0, fit=None, scale=1.0, vector=True, textscale=5, append=False, linfit=False, rms=True, plotname=None)[source]
Convert a XYXYMATCH file into a vector plot or set of residuals plots.
This function provides a single interface for generating either a vector plot of residuals or a set of 4 plots showing residuals. The data being plotted can also be adjusted for a linear fit on-the-fly.
- Parameters:
- coordfilestring
Name of file with matched sets of coordinates. This input file can be a file compatible for use with IRAF’s geomap.
- columnslist [Default: [0,1,2,3]]
Column numbers for the X,Y positions from each image
- datalist of arrays
If specified, this can be used to input matched data directly
- titlestring
Title to be used for the generated plot
- axeslist
List of X and Y min/max values to customize the plot axes
- everyint [Default: 1]
Slice value for the data to be plotted
- limitfloat
Radial offset limit for selecting which sources are included in the plot
- labelsizeint [Default: 8] or str
Font size to use for tick labels, either in font points or as a string understood by tick_params().
- ylimitfloat
Limit to use for Y range of plots.
- xlowerfloat
- ylowerfloat
Limit in X and/or Y offset for selecting which sources are included in the plot
- outputstring
Filename of output file for generated plot
- headlint [Default: 4]
Length of arrow head to be used in vector plot
- headwint [Default: 3]
Width of arrow head to be used in vector plot
- xshfloat
- yshfloat
Shift in X and Y from linear fit to be applied to source positions from the first image
- scalefloat
Scale from linear fit to be applied to source positions from the first image
- fitarray
Array of linear coefficients for rotation (and scale?) in X and Y from a linear fit to be applied to source positions from the first image
- vectorbool [Default: True]
Specifies whether or not to generate a vector plot. If False, task will generate a set of 4 residuals plots instead
- textscaleint [Default: 5]
Scale factor for text used for labelling the generated plot
- appendbool [Default: False]
If True, will overplot new plot on any pre-existing plot
- linfitbool [Default: False]
If True, a linear fit to the residuals will be generated and added to the generated residuals plots
- rmsbool [Default: True]
Specifies whether or not to report the RMS of the residuals as a label on the generated plot(s).
- plotnamestr [Default: None]
Write out plot to a file with this name if specified.
- drizzlepac.tweakutils.parse_atfile_cat(input)[source]
Return the list of catalog filenames specified as part of the input @-file
- drizzlepac.tweakutils.parse_colname(colname)[source]
Common function to interpret input column names provided by the user.
This function translates column specification provided by the user into a column number.
- Parameters:
- colname
Column name or names to be interpreted
- Returns:
- colslist
The return value will be a list of strings.
Notes
This function will understand the following inputs:
'1,2,3' or 'c1,c2,c3' or ['c1','c2','c3'] '1-3' or 'c1-c3' '1:3' or 'c1:c3' '1 2 3' or 'c1 c2 c3' '1' or 'c1' 1
- drizzlepac.tweakutils.parse_exclusions(exclusions)[source]
Read in exclusion definitions from file named by ‘exclusions’ and return a list of positions and distances
- drizzlepac.tweakutils.parse_skypos(ra, dec)[source]
Function to parse RA and Dec input values and turn them into decimal degrees
- Input formats could be:
[“nn”,”nn”,”nn.nn”] “nn nn nn.nnn” “nn:nn:nn.nn” “nnH nnM nn.nnS” or “nnD nnM nn.nnS” nn.nnnnnnnn “nn.nnnnnnn”
- drizzlepac.tweakutils.plot_zeropoint(pars)[source]
Plot 2d histogram.
- Pars will be a dictionary containing:
data, figure_id, vmax, title_str, xp,yp, searchrad
- drizzlepac.tweakutils.radec_hmstodd(ra, dec)[source]
Function to convert HMS values into decimal degrees.
This function relies on the astropy.coordinates package to perform the conversion to decimal degrees.
- Parameters:
- ralist or array
List or array of input RA positions
- declist or array
List or array of input Dec positions
- Returns:
- posarr
Array of RA,Dec positions in decimal degrees
See also
Notes
This function supports any specification of RA and Dec as HMS or DMS; specifically, the formats:
["nn","nn","nn.nn"] "nn nn nn.nnn" "nn:nn:nn.nn" "nnH nnM nn.nnS" or "nnD nnM nn.nnS"
- drizzlepac.tweakutils.read_ASCII_cols(infile, cols=[1, 2, 3])[source]
Interpret input ASCII file to return arrays for specified columns.
- Returns:
- outarrlist of arrays
The return value will be a list of numpy arrays, one for each ‘column’.
Notes
The specification of the columns should be expected to have lists for each ‘column’, with all columns in each list combined into a single entry.
For example:
cols = ['1,2,3','4,5,6',7]
where ‘1,2,3’ represent the X/RA values, ‘4,5,6’ represent the Y/Dec values and 7 represents the flux value for a total of 3 requested columns of data to be returned.
- drizzlepac.tweakutils.readcols(infile, cols=None)[source]
Function which reads specified columns from either FITS tables or ASCII files
This function reads in the columns specified by the user into numpy arrays regardless of the format of the input table (ASCII or FITS table).
- Parameters:
- infilestring
Filename of the input file
- colsstring or list of strings
Columns to be read into arrays
- Returns:
- outarrarray
Numpy array or arrays of columns from the table