From simard@nenuphar.as.arizona.edu Mon Mar 19 14:16:47 2001 Date: Mon, 19 Mar 2001 14:15:21 -0700 (MST) From: Luc Simard To: gim2d-list@nenuphar.as.arizona.edu Subject: GIM2D version 2.2.1 now available Dear GIM2D users, Version 2.2.1 is now available for your fitting pleasure at http://nenuphar.as.arizona.edu/simard/gim2d/installation.html This version includes a LOT (and I mean a LOT) of "under-the-hood" improvements. In addition to these improvements, three important changes should be noted: - You can now run the options dobkg=yes and initparam=no simultaneously - The PSF type "tiny_nic" has been split into tiny_nic (for NIC1 and NIC2) and tiny_3nic (for NIC3). The type "tiny_3nic" includes an extra convolution for the effect of the intrapixel response function of Camera 3. See the paper on the photometry of undersampled PSF's by Tod Lauer, PASP, 111, 1434 for more details. - If you do an "epar gim2d", you will now see a bunch of parameters that control the background parameter determination in the GIM2D tasks. The default values (reset by unlearning GIM2D if you need to) are the ones that have been used all along by GIM2D. I'm just giving people more freedom here. The parameters are : bkg_type = mean, median or mode. Self-evident bkg_rbbf = This is how far a pixel identified by SExtractor as a sky pixel must be from the lowest isophote of the nearest object in order to be considered as sky by GIM2D. bkg_clip = clipping threshold for bad background pixels. bkg_npix = Minimum number of pixels required for calculating background parameters. If the number of sky pixels is less than bkg_pix, GIM2D will issue a warning and proceed with the background level in your .mdpar file and the bkgsig value in your CL script. - New task GBKGMAKER. Very handy for constructing a background image for your simulations. From a list of input images, GBKGMAKER will grab background pixel values at random to make an output background image with dimensions specified by nxout and nyout. You can then use this background image as your template image for GSIMUL and C2GSIMUL. Note that the background image produced by GBKGMAKER will have the same distribution of pixel-to-pixel values as the input images, but background structures on larger scales (faint gals, flat-fields, etc.) will be lost. As is the case with any new GIM2D version, always keep a watchful eye for any problems, and email me your bug reports/problems. Enjoy! Luc +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Luc Simard Steward Observatory 933 North Cherry Avenue University of Arizona Tucson, AZ 85721, USA E-mail: lsimard@as.arizona.edu Phone: (520) 621-9262 Home page: http://nenuphar.as.arizona.edu/simard +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+