Vista mypro.pro string2 string3 string4 string5
 => runs Vista through mypro.pro, with string variable argN set to stringN
    if mypro.pro finishes with "end" Vista silently terminates

! Set (numeric) variables
set am=1145 bm=1222
! Snag FITS keywords NAXIS1 from header of buffer dest (variable)
set size={dest:NAXIS1}
! variable arithmetic is forward polish, beware.
set slope=-ydiff/xdiff
typ bias1
! String variables (different name space => can use same names as numeric)
string fnum '178'
! Set a string to token from file myfile, line k, token 2
string FIELD  '@myfile.dat#k#2'
! Evaluate a string as a portion of a command
rd 1 {mystring}

! Write variable info to a file
printf {FIELD}_{PATCH}_{DATE}_{INST}_{FILT}.{DITH}.{CHIP}
printf '%a30 %f8.1 %f8.3 %f8.3' {arg2} sky sens frng
! Execute a shell command
! Note that there cannot be a space between the ">" and the filename!
% ls WARP/f{field}_{patch}*.fits | wc  >{patlist}
% ls WARP/f{field}_{patch}*.fits | sed 's/_/ /g' >>{patlist}

! Define a box and perform analysis on an image
box 1 sx=0 sy=0 nx=512 ny=512
box 1 sx={3:CNPIX1} ex=520 sy=0 ny=1
abx  1 1 silent mean=a1 rms=rms median=med medrms=medrms sx=sx
! Interactively do image stats analysis
itv

! Image arithmetic with constants
ac  i=scratch bias1
sc  i=scratch bias1
mc  i=scratch bias1
dc  i=scratch bias1

! Image arithmetic with two images
ai i=fixflat i=scratch
si i=fixflat i=scratch
mi i=fixflat i=scratch
di i=fixflat i=scratch

! Mathematical functions
ln i=dest inv
log i=dest
min 1 2
sqrt i=dest

! Clip function
clip 1 max=thresh vmax=10000 min=0 vmin=-100
clip  i=dest sn=snbad snlim=snpoor tv

! Fit a surface, smooth and image
surface i=dest params=(x0,y0,0,slope,1,0,0,0)
smooth i=dest fwc=5
fiterpolate 8 nx=5 ny=4

! Shift an image
shift   1  dx=45 dy=1

! Create a new image
open 1 nx=512 ny=512
open 1 nx=512 ny=512 header=6
! Window down an old image
wind i=image box=1
! Copy an image
cop   20 1
cop   i=dest i=image box=1
cop 10 i=dest xbin=-2 ybin=2

! Interactively clean an image or do it automatically
tidy
clean i=dest

! Write some text into an image
wtext 1 just=8 value=2000 loc=(i*mx+m,j*my) label="{dith}.{chip}"

! Interactively examine/photometer stars and objects
psf scale=0.1375 rad=10
print phot
print phot file=save.dat
print phot diff

! Display an image
tv i=dest thresh=-200 sat=200 cf=jt
tv 1 screen=1 old sqrt
tv 1 zoom=-4
color bw inv
! Line graphics
plot 10 y=200
plot i=mybuf r=(6,5,0,1,2,3,4) save=dudley_nt1.spec

! Read an image
rd  1 sky.179
rd 10 ./nt1/lris0037 short
! Read the 7th image in a multi-extension fits file
rd 9 ./nt1/lris0037 mef=7
! Read the 2nd image in a 3-d fits file
rd 9 ./nt1/lris0037 3d=1

! Write an image
wd 1 afsky.cln unsigned
wd 1 zfringe.fits short
wd 5 iflat.016 unsigned scale=3.0
wd i=image fringe.{fnum}

! Call a procedure
call ./abflatten

! Branching constructs (only usable in non-command line procedures)
do k=2,nimage+1
  string FIELD  '@myfile.dat#k#2'
end_do

if xmin<ex&xmax>sx&ymin<ey&ymax>sy
   mc i=tmp 0
else_if rot=1&flip=0
   cop i=image i=image flip
end_if