Contents of IDL Astronomy User's Library Jul 2014 (also see http://idlastro.gsfc.nasa.gov/contents.html) Astronomical Utilities in pro/astro ________ -------- ADSTRING() - Format RA and DEC as a character string AIRTOVAC - Convert air wavelengths to vacuum wavelengths AITOFF - Convert longitude,latitude to X,Y using Aitoff equal-area projection AITOFF_GRID - Create an overlay grid using the AITOFF projection ALTAZ2HADEC - Convert Horizon (Alt-Az) coordinates to Hour Angle and Declination ARCBAR - Draw an arcbar over an image showing the astronomical plate scale ARROWS - Given a FITS header, display a "weathervane" showing N-E orientation ASTDISP - Display formatter for pixel + astronomical coordinates ASTRO - Interactive driver to compute astronomical precession, or coordinate conversions (calls EULER and PRECESS). BARYVEL - Compute components of barycentric Earth velocity, given Julian date BPRECESS - Precess coordinates, proper motion from J2000 to B1950 CALZ_UNRED - Deredden a galaxy spectrum using the Calzetti et al. (2000) formula CCM_UNRED - Deredden a spectrum using the Cardelli, Clayton and Mathis (1989) parameterization. CO_ABERRATION - Calculate changes to Ra and Dec due to aberration effects CO_NUTATE - Calculate changes in RA and Dec due to nutation of the Earth's rotation CO_REFRACT() - Calculate correction to altitude due to atmospheric refraction COSMO_PARAM - Derive a full set of cosmological parameters given a subset CT2LST- Convert from civil time to local sidereal time DATE() - Convert day of year to a DY-MON-CCYY string (FITS standard) DATE_CONV() - Function to perform various date format conversions DAYCNV- Convert from Julian Date to calendar date. DEREDD- Deredden Stromgren indices (called by UVBYBETA) ECI2GEO() - Convert Earth-centered inertial coordinates to geographic coords EQ2HOR - Convert celestial (ra-dec) coords to local horizon coords (alt-az). EQPOLE - Convert longitude,latitude to X,Y using polar equal-area projection EQPOLE_GRID - Create overlay grid using polar equal-area projection EULER - Astronomical coordinate system conversions FLUX2MAG() - Convert from flux units to magnitudes FM_UNRED - Deredden a spectrum using the Fitzpatrick & Massa (1998) parameterization. GAL_UVW - Calculate the Galactic space velocity (U,V,W) of a star GAL_FLAT() - Correct a galaxy image for inclination effects. GALAGE - Derive a galaxy age as a function of redshift for a cosmological model GCIRC - Compute rigorous great circle distance GEO2ECI() - Convert geographic coordinates to Earth-centered inertial coords GEO2GEODETIC() - Convert from geographic to geodetic coordinates GEO2MAG() - Convert from geographic to geomagnetic coordinates GEODETIC2GEO() - Convert from geodetic to geographic coordinates GET_COORDS - Read in angular input in decimal or sexigesimal format GET_DATE - Get the current date in CCYY-MM-DD format (FITS standard) GET_JULDATE - Get the current Julian date as a double precision scalar GLACTC- Convert between Galactic (or SuperGalactic) and equatorial coordinates GLACTC_PM - Convert between celestial and Galactic (or Supergalactic) proper motion HADEC2ALTAZ - Converts Hour Angle and Declination to Horizon (alt-az) coordinates HELIO - Compute (low-precision) heliocentric coordinates of the planets HELIO_JD() - Convert geocentric (reduced) Julian date to heliocentric Julian date HELIO_RV() - Compute radial velocity given binary star orbit parameters HOR2EQ - Convert local horizon coords (alt-az) to equatorial (ra-dec). IMCONTOUR - Contour plots with astronomical labeling (either RA,Dec or arc distance from the image center IMF() - Return values for a multi-component power law initial mass function ISMEUV() - Compute EUV optical depth due to photoionization of HI, HeI and HeII JDCNV - Convert from calendar date to Julian date. JPLEPHINTERP - Interpolate position and motion of planetary bodies (JPL Ephemeris) JPLEPHREAD - Open and read JPL DE200 or DE405 Ephemeride FITS File JPRECESS - Precess positions & proper motions from B1950 to J2000 JULDATE-Convert from calendar date to reduced Julian date. LSF_ROTATE - Create a 1-d convolution kernel to broaden a spectrum from a rotating star LUMDIST - Return luminosity distance for a given redshift & cosmological model MAG2GEO() - Convert from geomagnetic to geographic coordinates MAG2FLUX() - Convert from magnitudes to flux units MONTH_CNV() Convert a month name to the equivalent number or vice-versa MOONPOS- Compute the RA and Dec (and distance) of the Moon at a given date MPHASE - Compute illuminated fraction of the Moon's disk for given Julian dates NUTATE - Compute the nutation in longitude and latitude for given Julian date(s) OBSERVATORY - Return coordinates, altitude & time zones of an observatory PLANCK() - Returns a blackbody flux for a given effective temperature PLANET_COORDS - Return low-precision RA and Dec of planets give a date(s) POSANG - Compute the position angle between sources of specified RA and Dec PRECESS - Precess RA and Dec to a new equinox PRECESS_CD - Precess the PC (or CD) matrix in a FITS header to a new equinox PRECESS_XYZ - Precess equatorial geocentric rectangular coordinates PREMAT() - Returns precession matrix from equinox 1 to equinox 2 QDCB_GRID - Create overlay grid using COBE quad cube database coordinates RADEC - Format RA, Dec as Hours,Min,Sec,Deg,Min,Sec SIXTY - Convert decimal number to sexigesimal SPHDIST() - Find angular distance on a sphere (in /jhuapl) SUNPOS - Compute the RA and Dec of the Sun at a given date TDB2TDT() - Relativistic clock corrections due to Earth motion in solar system TEN() - Convert sexigesimal number to decimal TENV() - Like TEN but will work on a vector of sexigesimal numbers. TICPOS - Specify distance between tic marks for astronomical coordinates TICLABELS - Create labels for astronomical coordinate tick marks TICS - Compute the optimum distance between tic marks for astronomical labeling TIC_ONE - Determine optimum position of the first tic in astronomical labeling UVBYBETA - Use Stromgren indices to derive dereddened colors, metallicity, and effective Temperature. VACTOAIR - Convert vacuum wavelengths to air wavelengths. XYZ - Compute heliocentric rectangular coordinates at given Julian date. YMD2DN() - Convert year,month,day to day number of the year (in /jhuapl) YDN2MD - Convert day number of the year to year, month,day ZANG() - Compute angular size as a function of redshift in a Friedman cosmology ZENPOS - Compute the RA and Dec of the local zenith at a given date ---------------------------------------------------------------------------- DAOPHOT-Type Photometry Procedures in pro/idlphot (see text/daophot.tex) ________ -------- APER - Circular APERture photometry CNTRD - Obtain the centroid of a star by locating where derivatives go to zero DAOERF - Calculate the intensity, (and optionally, the derivatives) of a bivariate Gaussian, integrated over pixels. Called by DAO_VALUE DAO_VALUE - Obtain the value of a DAOPHOT PSF function at a given set of points FIND - FIND point sources within an image GCNTRD - Determine centroid by Gaussian fits to the marginal X,Y distributions GETPSF - Obtain a PSF (Gaussian + residuals) from isolated stars. GROUP - Place stars with non-overlapping PSF's in distinct groups MMM - (Mean, Median, Mode) sophisticated sky background computation NSTAR - Simultaneous PSF fitting of a group of stars PIXWT - Compute the area of the intersection of a circle on a rectangle PKFIT - Fit a Gaussian + residuals to a isolated star (called by GETPSF) RDPSF - Read a PSF file that was created by GETPSF into an IDL array. RINTER - Cubic Interpolation at a set of reference points, optionally obtain derivatives. (in /image) SKY - Compute image sky level using MMM SRCOR - Correlate the source positions in two different lists SUBSTAR- Subtract a scaled PSF at specified star positions T_APER - Driver procedure for APER with I/O to a disk FITS ASCII table T_FIND - Driver procedure for FIND with I/O to a disk FITS ASCII table T_GROUP- Driver procedure for GROUP with I/O to a disk FITS ASCII table T_GETPSF - Driver procedure for GETPSF with I/O to a disk FITS ASCII table T_NSTAR - Driver procedure for NSTAR with I/O to a disk FITS ASCII table T_SUBSTAR - Driver procedure for SUBSTAR with I/O to a disk FITS ASCII table ----------------------------------------------------------------------- Database Procedures in pro/database (see text/database.tex) ____________ ------------ DBBUILD - Load or append a database with new entry values. DBCIRCLE() - Find entries within a specified circular area. DBCLOSE - Close a database DBCOMPARE - Display the values of two database entries side by side DDBCREATE - Create a new database data, index and/or format file. DBDELETE - Delete an entry from a database DBEDIT - Interactively edit the entries in a database DBEXT - Extract items from a database into IDL variables DBFIND() - Find entries meeting specified criteria in an IDL database DBGET() - Use instead of DBFIND when search values are in an IDL vector DBHELP - List names of databases, or entries within a database DB_INFO() - Lower level routine to obtain information on an opened database DBINDEX - Update the IDL database index file. DB_ITEM_INFO() - Lower level routine to obtain information on specified item(s) DB_ITEM - Lower level routine to return item number and other information DBMATCH() - Match database entries one-to-one to specified item values DBOPEN - Open a IDL database DBPRINT - Print specified fields about specified entries in an IDL database DBPUT - Lower level routine to place new value for specified item into an entry DBRD - Lower level routine to read an entry from a database DBSORT() - Sort entries in an IDL database DBTARGET() - Find entries within specified distance of an astronomical target DBUPDATE - Update an IDL database with new item values. DB_OR() - Combine two catalog entry lists, removing duplicate values DBVAL - Lower level routine to extract value of specified item from an entry DBXVAL - Lower level routine to extract values of specified item from an entry DBWRT - Lower level routine to update or add a new entry to a database IMDBASE - Find all catalog sources within the field of an astronomical image DB_ENT2EXT,DB_ENT2HOST,DBEXT_DBF,DBEXT_IND,DBXPUT,DBFPARSE,DBFIND_ENTRY, DBFIND_SORT,DBSEARCH,DBTITLE,DB_TITLE() - Lower level database procedures ---------------------------------------------------------------------------- Disk I/O (e.g. IRAF files) in pro/disk_io _________ --------- IRAFDIR - Describe IRAF images on specified directory IRAFRD - Read a disk IRAF image file into IDL variables. IRAFWRT - Write IDL image and header to an IRAF (.pix & .imh) file READ_FMR() - Read a journal (ApJ, AJ) machine-readable table into IDL WFPC2_READ - Read a Wide Field/Planetary Camera 2 (WFPC2) image ----------------------------------------------------------------------- FITS Astrometry and Calibration in pro/astrom (see text/astrom.tex) ________ -------- ADD_DISTORT - Add SIP distortion parameters into a FITS header AD2XY - Use astrometry structure to convert celestial to pixel coordinates ADXY - Use FITS header to convert celestial (RA,Dec) to pixel coordinates CONS_DEC() - Obtain the X and Y coordinates of a line of constant declination CONS_RA() - Obtain the X and Y coordinates of a line of constant right ascension EXTAST- EXTract ASTrometry parameters from a FITS header into an IDL structure FITS_CD_FIX - Update obsolete representations of the CD matrix in a FITS header GET_EQUINOX() - Return a numeric equinox value from a FITS header GETROT - GET ROTation and plate scale from a FITS header GSSS_STDAST - Insert the closest tangent projection astrometry into an STScI Guidestar Survey Image GSSSADXY - Convert RA, Dec to pixel coordinates for an STScI survey image GSSSEXTAST - Extract astrometry parameters from an STScI Survey Image GSSSXYAD - Convert pixel coordinates to RA, Dec for an STScI survey image HASTROM - Rotate, Congrid, and/or shift an image until astrometry matches that in a reference FITS header. Used to align images. HBOXAVE - Boxaverage an image and update astrometry in a FITS header HCONGRID - CONGRID an image and update astrometry in a FITS header HEULER - Convert between Galactic, celestial and ecliptic coordinates in FITS a header HEXTRACT - Extract a subimage and update astrometry in a FITS header HPRECESS - Precess the astrometry in a FITS header to a new equinox. HREBIN - REBIN an image and update the astrometry in a FITS header HREVERSE - Reverse an image about either dimension and update astrometry in a FITS header HROT - Rotate an image and update astrometry in a FITS header. HROTATE - Apply IDL ROTATE function and update astrometry in a FITS header MAKE_ASTR - Build an astrometry structure from input parameter values PRECESS_CD - Precess coordinate description (CD) matrix in a FITS header to a new equinox. Called by HPRECESS PUTAST - Put astrometry parameters (e.g. rotation, plate scale) into a FITS header. SIP_EVAL() - Compute distorted coordinates given SIP (simple imaging polynomial) coefficients SOLVE_ASTRO - Solve for an tangent-plane astrometric plate solution with optional distortion terms. STARAST - Obtain an exact astrometry solution given the coordinates and plate position of 2 or 3 stars. TNX_EVAL() - Compute distorted coordinates give TNX (IRAF) projection TPV_EVAL() - Compute distorted coordinates given TPV (Tangent + PV_ polynomial) coefficients UPDATE_DISTORT - Update SIP astrometry coefficients for a linear transformation WCS_CHECK_CTYPE - Check that pair of CTYPE parameters conform to WCS format. WCS_GETPOLE - Compute the coordinates of the native pole for non-polar projection WCSSPH2XY - Convert between longitude,latitude to X,Y angular coordinates for 25 different map projection types WCSXY2SPH - Inverse of WCSSPH2XY WCS_DEMO - Demo program for WCSSPH2XY and WCSXY2SPH WCS_ROTATE - Rotate between standard (e.g. celestial) and native coordinates XYAD - Use FITS header to convert pixel (X,Y) to celestial(RA, Dec) coordinates XY2AD - Use astrometry structure to convert pixel to celestial coordinates XYXY - Convert X,Y values on one image to X,Y values in another image using astrometry in the FITS headers ---------------------------------------------------------------------------- STSDAS Image manipulation in pro/sdas ________ -------- EXTGRP - Extract group parameter information out of SXREAD output ST_DISKREAD - Read an HST FITS file and reconstruct a GEIS (STSDAS) file SXGINFO - Return info on all group parameters in a FITS header SXGPAR() - Obtain group parameter values from a FITS header and parameter block SXGREAD() - Read group parameters from an STSDAS file SXHCOPY - Copy a selected portion of one header into another SXHMAKE - Create a basic STSDAS header file from an IDL data array SXHREAD - Read a STSDAS header from disk SXHWRITE - Write a STSDAS header to disk SXMAKE - Make a basic STSDAS header from an IDL array SXOPEN - Open an STSDAS disk file for subsequent I/O SXREAD() - Read an STSDAS image from disk SXWRITE - Write an image to STSDAS format ---------------------------------------------------------------------------- FITS ASCII & Binary Table I/O in pro/fits_table ( see text/ft.tex ) ________ -------- FTAB_DELROW - Delete specified rows in a FITS table extension FTAB_EXT - Extract specified columns of a FITS table extension into IDL vectors FTAB_HELP - Print info about the fields in a FITS table extension FTAB_PRINT - Print specified columns and rows of a FITS table extension FTADDCOL - Add a new column to a FITS ASCII table FTCREATE - Create an empty FITS ASCII table header and data array FTDELCOL - Delete specified column from a FITS ASCII table data array FTDELROW - Delete specified row(s) from a FITS ASCII table data array FTGET() - Extract a specified field from a column in a FITS ASCII table array FTHELP - Display the fields in a FITS ASCII table header FTHMOD - Modify the attributes of a field in a FITS ASCII table FTINFO - Return an informational structure from a FITS ASCII table header FTKEEPROW - Subscript (and reorder) a FITS ASCII table array FTPRINT - Print specified columns and rows in a FITS ASCII table array FTPUT - Update or add data to a field in a FITS ASCII table array FTSIZE - Return the size and number of fields in a FITS ASCII table array FTSORT - Sort a FITS ASCII table according to the values in a specified field. TBDELCOL - Delete specified column from a FITS Binary table array TBDELROW - Delete specified row(s) from a FITS Binary table array TBGET() - Extract a specified field from a column in a FITS Binary table TBHELP - Display the fields in a FITS Binary table header TBINFO - Return an informational structure from a FITS Binary table header TBPRINT - Print specified columns and rows in a FITS Binary table array TBSIZE - Return the size and number of fields in a FITS Binary table array ------------------------------------------------------------------------- FITS Binary Table Extensions I/O in pro/fits_bintable _________ --------- FXADDPAR - Add or modify a parameter in a FITS header array. FXBADDCOL - Adds a column to a binary table extension. FXBCLOSE - Close a FITS binary table extension opened for read. FXBCOLNUM() - Returns a binary table column number. FXBCREATE - Open a new binary table at the end of a FITS file. FXBDIMEN() - Returns the dimensions for a column in a FITS binary table. FXBFIND - Find column keywords in a FITS binary table header. FXBFINDLUN() - Find logical unit number UNIT in FXBINTABLE common block. FXBFINISH - Close a FITS binary table extension file opened for write. FXBGROW - Increase the number of rows in a binary table FXBHEADER() - Returns the header of an open FITS binary table. FXBHELP - Prints short description of columns in a FITS binary table. FXBHMAKE - Create basic FITS binary table extension (BINTABLE) header. FXBINTABLE - Common block FXBINTABLE used by "FXB" routines. FXBISOPEN() - Returns true if UNIT points to an open FITS binary table. FXBOPEN - Open FITS binary table extension for read or update FXBPARSE - Parse the binary table extension header. FXBREAD - Read a data array from a disk FITS binary table file. FXBREADM - Read multiple columns/rows from a FITS binary table file. FXBSTATE() - Returns the state of a FITS binary table. FXBTDIM() - Parse TDIM-like keywords. FXBTFORM - Returns information about FITS binary table columns. FXBWRITE - Write a binary data array to a disk FITS binary table file. FXBWRITM - Write multiple columns/rows to a FITS binary table file FXFINDEND - Find the end of a FITS file. FXHCLEAN - Removes required keywords from FITS header. FXHMAKE - Create a basic FITS header array. FXHMODIFY - Modify a FITS header in a file on disk. FXHREAD - Reads a FITS header from an opened disk file. FXPAR() - Obtain the value of a parameter in a FITS header. FXPARPOS() - Finds position to insert record into FITS header. FXREAD - Read basic FITS files. FXWRITE - Write a disk FITS file. ------------------------------------------------------------------------- FITS I/O in pro/fits _________ --------- CHECK_FITS - Check that array agrees with NAXISi, BITPIX keywords of FITS header FITSDIR - Display info about primary FITS header(s) on disk FITSRGB_to_TIFF - Combine separate red, green, blue FITS files into TIFF format FITS_ADD_CHECKSUM - Add/update the CHECKSUM/DATASUM keywords in a FITS header FITS_ASCII_ENCODE() - Encode an unsigned longword as an ASCII string FITS_CLOSE - Close a FITS file defined by a FITS Control Block (see FITS_OPEN) FITS_HELP - Summarize the primary data units and extensions in a FITS file FITS_OPEN - Open a FITS file and define a FITS Control Block (FCB) FITS_READ - Read a FITS file specified by name or FITS Control Block (FCB) FITS_TEST_CHECKSUM() - Verify the values of the CHECKSUM/DATASUM FITS keywords FITS_WRITE - Write a FITS primary data unit or extension FITS_INFO - Display info about disk FITS file(s) at a terminal or in Common FXMOVE() - Skip a specified number of extensions in a FITS file FXPOSIT() - Open a FITS file positioned to beginning of a specified extension HEADFITS() - Read a FITS header from a disk FITS file. MKHDR - Make a minimal FITS header for an image array. MODFITS - Modify the header or data in a FITS array (without changing the size) MRDFITS() - Read FITS file mapping table columns into IDL structure tags MRD_HREAD - Like FXHREAD but can also read a FITS header from a Unix pipe MWRFITS - Write a FITS file from a IDL array or structure RDFITS_STRUCT - Read an entire disk FITS file into an IDL structure READFITS() - Read a disk FITS file into an IDL data and header array. SXADDHIST - Add a history record to a FITS header SXADDPAR - Add or modify a parameter in a FITS header SXDELPAR - Delete a keyword from a FITS header SXPAR() - Obtain the value of a keyword in a FITS header WRITEFITS - Write IDL data and header array to a disk FITS file. ----------------------------------------------------------------------------- Image Manipulation in pro/image _______ ------- BOXAVE() - Boxave an image, always using at least REAL*4 arithmetic CONVOLVE() - Convolve an image with a PSF using the product of Fourier Transforms CORREL_IMAGES() - Correlation of two images. Called by CORREL_OPTIMIZE CORREL_OPTIMIZE - Compute the optimal pixel offset of one image relative to another by maximizing the correlation function. CORRMAT_ANALYZE - Analyze the correlation function made by CORREL_IMAGE CR_REJECT - General iterative cosmic ray rejection for 2 or more images DIST_CIRCLE - Create a mask array useful for circular aperture photometry. DIST_ELLIPSE - Create a mask array useful for elliptical aperture photometry. FILTER_IMAGE() - Like MEDIAN or SMOOTH but handles edges & allows iteration FREBIN - Expand or contract an image while conserving flux IMLIST - Display image pixel values around a specified center MAX_ENTROPY - Deconvolution by Maximum Entropy, given a PSF MAX_LIKELIHOOD - Deconvolution by maximum likelihood, given a PSF MEDARR - Median filter across a set of images (e.g. for cosmic ray removal) POSITIVITY() - Map an image uniquely and smoothly into all positive values PSF_GAUSSIAN() - Create a 1-d, 2-d, or 3-d Gaussian with specified FWHM, center SIGMA_FILTER() - Replaces pixels deviant by more than a specified sigma from its neighbors. Useful for cosmic ray removal. SKYADJ_CUBE - Remove the sky level from individual images of a data cube XMEDSKY - Compute the median sky as a 1-d function of X (for slitless spectra) ---------------------------------------------------------------------------- Math and Statistics in pro/math _________ --------- ASINH() - Return the inverse hyperbolic sine of its argument AVG() - Return the average value of an array or 1 dimension of an array. CIC - Cloud In Cell interpolation of irregularly gridded data CSPLINE() - Interpolate using the Numerical Recipes natural cubic spline FACTOR - Find the prime factors of a given number (in /jhuapl) FITEXY - Best straight-line fit to data with errors in both coordinates FLEGENDRE() - Compute the first M terms in a Legendre polynomial expansion GAUSSIAN() - Evaluate a 1-d Gaussian and optionally its derivative HERMITE() - Interpolate a tabulated function using a Hermite spline KSONE - Compute the one-sided Kolmogorov-Smirnov statistic KSTWO - Compute the two-sided Kolmogorov-Smirnov statistic KUIPERONE - Compute the one-sided Kuiper statistic (NR) KUIPERTWO - Compute the two-sided Kuiper statistic (NR) LINMIX_ERR - Bayesian approach to linear regression with errors in both X and Y LINTERP - Linearly interpolate X,Y vectors onto a new X grid MEANCLIP - Compute an iteratively sigma-clipped mean on a data set MLINMIX_ERR : Bayesian approach to linear regression with errors in both X and Y and multiple independent variables. MINF_BRACKET - Find 3 points which bracket the minimum of a function MINF_CONJ_GRAD - Find local minimum of a scalar valued function of several variables using conjugate gradient method MINF_PARABOLIC - Minimize a function using Brent's method with parabolic interpolation MINF_PARABOL_D - Minimize a function using Brent's method with derivatives MLINMIX_ERR : Bayesian approach to linear regression with errors in both X and Y and multiple independent variables. MRANDOMN : Generate random vectors from a multivariate normal density. MULTINOM - Simulate multinomial random variables NGP - Nearest Grid Point interpolation of irregularly gridded data PCA - Perform a principal component analysis (Karhunen-Loeve expansion) PENT() - Return the information entropy S of time-series data for a set of trial periods PERMUTE() - Rearrange the elements of an array in random order POIDEV() - Generate a Poisson random deviate POLINT - Polynomial interpolation of an (X,Y) pair POLYLEG() - Evaluate a Legendre polynomial with specified coefficients POLY_SMOOTH() - Apply a least-squares (Savitzky-Golay) polynomial smoothing filter PRIME - Return the first N primes (in /jhuapl) PROB_KS - Return the significance of a Kolmogorov-Smirnov statistic PROB_KUIPER - Return the significance of the Kuiper statistic QSIMP - Integrate using Simpson's rule to specified accuracy QTRAP - Integrate using trapezoidal rule to specified accuracy. QUADTERP - Quadratic interpolation of X,Y vectors onto a new X grid RANDOMCHI - Generate chi-square distributed random variables RANDOMDIR - Generate Dirichlet-distributed random variables RANDOMGAM - Generate random numbers from a gamma distribution. RANDOMP - Create a vector of random numbers distributed as a power-law RANDOMWISH - Draw random matrices from a Wishart distribution SAFE_CORRELATE() - compute the probability that data is uncorrelated while accounting for data uncertainties SIXLIN - Compute linear regression by 6 different methods. SPLINE_SMOOTH - Compute cubic smoothing spline to (weighted) data TABINV - Find the effective index of a function value. TRANSFORM_COEFF - Compute new polynomial coefficients under a linear transformation TRAPZD - Compute Nth iteration of trapezoidal rule. Called by QSIMP, QTRAP TSC - Triangular Shaped Cloud interpolation of irregularly gridded data onto a regular grid TSUM() - Trapezoidal integration of the area under a curve ZBRENT() - Find the root of a function known to lie between specified limits ---------------------------------------------------------------------------- Plotting Procedures in pro/plot ------------ ------------ CLEANPLOT - Reset all plotting system variables to their default (X) values AL_LEGEND - Create an annotation legend for a plot AL_LEGENDTEST - Demo program demonstrating the capabilities of AL_LEGEND LINEID_PLOT - Annotate the identified lines in a spectrum MULTIPLOT - Create multiple plots with shared axes OPLOTERROR - Overplot Y vs. X with optional X and Y error bars PARTVELVEC - Plot the velocity vectors of a set of particles PLOTERROR - Plot Y vs. X with optional X and Y error bars PLOTHIST - Plot the histogram of an array PLOTSYM - Define useful plotting symbols not in the standard PSYM definition RDPLOT - Like intrinsic CURSOR procedure but with a full-screen cursor SUNSYMBOL() - Return the character string to plot a subscripted Sun symbol VSYM - Create "Mongo"-like plotting symbols, rotationally symmetric polygons ---------------------------------------------------------------------------- Robust Statistics procedures in pro/robust ___________ ----------- AUTOHIST - Draw a histogram using automatic bin-sizing. BIWEIGHT_MEAN() - Iterative biweighted determination of mean and standard deviation HISTOGAUSS - Outlier-resistant autoscaled histogram drawing MEDSMOOTH() - Median smoothing including the points at the ends RESISTANT_MEAN - Outlier-resistant determination of mean and std. deviation. ROB_CHECKFIT() - Utility to determine quality of a fit and return biweights ROBUST_LINEFIT() - Robust fit of Y vs X (or bisector of Y vs X and X vs Y) ROBUST_POLY_FIT() - Robust polynomial fit ROBUST_SIGMA() - Robust analog of the standard deviation ---------------------------------------------------------------------------- IDL Structure procedures in pro/structure ___________ ----------- COMPARE_STRUCT() - Compare all matching Tag names and return differences COPY_STRUCT - Copy Fields with matching Tag names from one structure to another CREATE_STRUCT - Create an IDL structure from a list of tag types and dimensions MRD_STRUCT() - Like CREATE_STRUCT but tag values can be specified in a string PRINT_STRUCT - Print specified tags from structure (to LUN if given) TAG_EXIST() - Determine if a tag exists in a given structure WHERE_TAG() - Like WHERE but works on a structure tag names ---------------------------------------------------------------------------- Web Socket Procedures in pro/sockets ___________ ----------- WEBGET() - Use the IDL SOCKET procedure to get data from http servers QUERYGSC() - Query the Guide Star Catalog (GSC V2.3.2) at STScI by position QUERYDSS - Query the digital sky survey (DSS) online at the ESO or STSCI servers QUERYSIMBAD - Query the SIMBAD or NED name resolver to obtain J2000 coordinates QUERYVIZIER() - Positional query of any catalog in the VIZIER database. QUERY_IRSA_CAT - queries IRSA catalogs, returning an IDL structure READ_IPAC_TABLE - reads an IPAC Table file into an IDL structure READ_IPAC_VAR - converts an internal variable to an IDL structure WRITE_IPAC_TABLE - writes an IDL structure to an IPAC Table file ---------------------------------------------------------------------------- TV Display Procedures in pro/tv ___________ ----------- BLINK - Blink two or more windows in an image display CURS - Change the shape of the (X windows only) cursor CURVAL - Interactive display of image intensities and astronomical coordinates PIXCOLOR - Set specified pixel values to a specified color SIGRANGE() - Find range of pixel values which contain 90% of the image values TVBOX - Draw a box of specified size on the image display TVCIRCLE - Draw a circle of specified radius on the image display TVELLIPSE - Draw an ellipse of specified axes on the image display TVLASER - Write an image to postscript file with annotation from a FITS header TVLIST - Display intensity values surrounding the cursor position UNZOOM_XY - Convert from window coordinates to image coordinates ZOOM_XY - Convert from image coordinates to window coordinates ----------------------------------------------------------------------------- Miscellaneous (Non-Astronomy) Procedures in pro/misc ________ -------- ASTROLIB - Add the non-standard system variables used in the IDL Astronomy User's Library BLKSHIFT - Shift a block of data to a new (possibly overlapping) position in a file BOOST_ARRAY - Append one array onto another, adjusting dimensions if necessary BREAK_PATH() - break up a !PATH-like string into individual directories BSORT() - Like the IDL SORT function but subscript order is maintained when value are equal -- like a bubble sort. CHECKSUM32 - Compute the 32bit checksum of an array (ones-complement arithmetic) CIRRANGE - Force an angle to be in the range 0 to 360 (or 0 to 2*!PI). CONCAT_DIR - concatenate directory and file name for current OS DELVARX - Delete an IDL variable; like DELVAR but works at any calling level DETABIFY() - Replace tabs in a character string by equivalent number of spaces EXPAND_TILDE() - Expand tilde in UNIX directory names F_FORMAT() - Find the "best" F format to display an array of REAL*4 numbers. FDECOMP - Decompose a file name (Disk + Directory + Name + Extension + Version) FINDPRO - Find all occurrences of a procedure in one's !PATH FIND_ALL_DIR - Find all directories under a specified directory FIND_WITH_DEF - Search for files with default path and extension FORPRINT -Print a set of vectors by looping over each index value GET_PIPE_FILESIZE - Determine the number of bytes in a unit opened as a pipe with SPAWN GETOPT() - Parse a user supplied string into numeric value(s). GETPRO - Search !PATH directory for a procedure and copy into user's directory GETTOK() - Extract a string up to a specified character. GETWRD() - Get specified item (word) from a string (in /jhuapl) HGREP - Find a substring in a FITS header or other string array HOST_TO_IEEE - Convert IDL variable from host machine bit order to IEEE HPRINT - Pretty terminal display of a FITS header (or other string array) IEEE_TO_HOST - Convert IDL variable from IEEE bit order to host machine ISARRAY() - Determine if an IDL variable is an array (in /jhuapl) IS_IEEE_BIG() - Determine if the host machine is IEEE big endian LIST_WITH_PATH() - Search for files within specified directory path MAKE_2D - Change from 1-D indexing to 2-D indexing MATCH - Find the subscripts where the values of two vectors match. MATCH2 - Find the matches for each element of two arrays. MRD_SKIP - Skip a number of bytes from current location in a file or a Unix pipe MINMAX() - Return the min and max of an array in an 2 element vector N_BYTES() - Return the number of bytes in an IDL variable NINT() - Like intrinsic ROUND() function but returns integer instead of long NULLTRIM() -Delete all characters after, and including, the the first null byte(0). Called by TAB_PUT. ONE_ARROW - Draw an arrow labeled with a single character ONE_RAY - Draw a ray by specifying starting point, angle, and length ORDINAL() - Return the English equivalent of ordinal numbers, i.e. '1st','2nd' POLREC - Convert from polar to rectangular coordinates (in /jhuapl) QGET_STRING() - Read a string (eg. password) from the keyboard without echoing it RDFLOAT - Quickly read an ASCII file with columns of data into IDL vectors READCOL - Read a file of free-format ASCII columns into IDL vectors READFMT - Quickly read a file of fixed-format ASCII columns into IDL vectors READ_KEY() - Like GET_KBRD but returns a code for escape sequences. RECPOL - Convert from rectangular to polar coordinates (in /jhuapl) REMCHAR - Remove all appearances of a character from a string. REM_DUP() - Remove duplicate values from a vector. REMOVE - Contract a vector or up to 8 vectors by removing specified elements REPCHR() - Replace all occurrences of one character by another (in /jhuapl) REPSTR() - Replace all occurrences of one substring in a string by another. SELECT_W - Allow user to interactively select from a list of strings SPEC_DIR() - Complete specification of a file name using default disk & directory STORE_ARRAY - Insert one array into another, adjusting dimensions if necessary STRCOMPRESS2() - Remove blanks around specified spaces in a string STRN() - Convert a number to a string and remove padded blanks. STRNUMBER()- Determine whether a string is a valid numeric value. TEXTOPEN - Open a file for text output as specified by TEXTOUT keyword TEXTCLOSE - Close a file that had been opened by TEXTOPEN. TO_HEX() - Translate a decimal integer to a hex string. VALID_NUM() - Determine if a string is a valid number (cf. STRNUMBER) VECT() - Display a set of numbers to a string with delimiters WHERENAN() - Find points equal to big-endian IEEE NaN (not a number) values XDISPSTR - Widget display of a string array with a simple search facility ZPARCHECK - Check the type and size of a parameter