Modified Commands

The following applications have been modified:

CHPIX

• There is a new output Parameter OLDVAL. If the section being modified comprises one pixel, OLDVAL stores the original value of that pixel.

COLLAPSE

• There are eleven new statistics available to estimate the output values, intended for cube analysis.
• The collapsed NDF is now physically smaller than the input NDF.

CONTOUR

• Parameter MODE has a new option to calculate contour heights called "Scale". This sets a specified number of contour levels to be equally spaced between two pixel values that you supply.
• Parameter AXIS now defaults to null (!), causing axes to be drawn if and only if the graphics device is cleared before the contours are plotted, as controlled by the Parameter CLEAR.

CONVOLVE

• This application can now smooth three-dimensional NDFs, in the sense that it will apply the PSF convolution to all the two-dimensional planes within a three-dimensional NDF independently. The smoothing plane can be parallel to any face of the cube and is defined by a new Parameter AXES.

COPYBAD

• COPYBAD now has an extra parameter called INVERT which, if set TRUE, causes output pixels to be set bad if the corresponding pixels in the reference NDF are good.

CURSOR

• CURSOR can now display the pixel value at each selected position (if the position falls within the bounds of a displayed NDF). This is controlled via the new Parameters SHOWDATA and COMP.
• The format of the displayed results has been changed so that the axis symbols and units are on a separate line to the axis values.

FITSEXIST

• It is now a self-contained application. It needs only read access to an NDF, unlike the former version that was an alias to FITSMOD. It should be faster too.

FITSVAL

• It is now a self-contained application for the reasons given in FITSEXIST above.

GAUSMOOTH

• This application can now smooth three-dimensional NDFs, in the sense that it will smooth all the two-dimensional planes within a three-dimensional NDF independently, using the same two-dimensional Gaussian filter. The smoothing plane can be parallel to any face of the cube, and is defined by a new Parameter AXES.

HISTOGRAM

• A new parameter called CUMUL has been added. Setting CUMUL to TRUE will result in a cumulative histogram being produced.

LISTMAKE

• The MODE parameter now has an option ``Good'' which is like the existing ``Pixel'' option in that it creates a list containing pixel centres taken from the supplied NDF, but differs in that it only stored the centres of pixels which have a good value in the NDF Data array (the ``Pixel'' option stores all pixel centres, whether the pixel values are good or bad).

LOOK

• New FORMAT option ``cglist'' added. This is like ``clist'' except that bad values are not included in the list.

NDFTRACE

• Now displays details of the scaling used for Data or Variance arrays that are stored in ``SCALED'' format.

PARGET

• Now permits single elements of a parameter array to be reported. One usage is when any values of an array contain embedded spaces.

PASTE

• A list of the input NDFs may now be given as a group through Parameter IN, permitting indirection through a text file. The first NDF is the base, and subsequent NDFs are pasted in the order supplied. The former method, where IN solely defines the base NDF and the pasted NDFs are specified through Parameters P1 to P25, is still available.

REGRID and WCSALIGN

• These applications now have options for using a rebinning algorithm rather than a resampling algorithm. Rebinning produces accurate flux conservation. See the new REBIN parameter.

• Now have an option to produce approximate flux conservation when using the traditional resampling algorithm. See the new Parameter CONSERVE.

• Now have options to use resampling or rebinning kernels based on a sombrero function $2*J_{1}(x)/x$ , where $J_{1}(x)$ is the first-order Bessel function of the first kind.

• The default values for the TOL parameter for REGRID, and the ACC parameter for WCSALIGN, have been reduced to 0.05, in order to reduce artefacts when transforming large images with flux conservation.

SETVAR

• Now provides the option to copy values from another NDF into the VARIANCE  component of the NDF being modified.

SLIDE

• Hitherto non-integer shifts resulted in a bad value appearing in the first or last element of the AXIS centres causing hazards to other applications. SLIDE now replaces the bad axis centre with an extrapolated value derived from the increment between the next good interior pair of AXIS centres.

WCSATTRIB

• This now only demands read-access to the NDF for MODE='Get'.