Re: FITS Format
- To: mathgroup at smc.vnet.net
- Subject: [mg38323] Re: [mg38273] FITS Format
- From: Dale Horton <daleh at wolfram.com>
- Date: Thu, 12 Dec 2002 01:35:34 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
At 03:17 AM 12/10/2002, Pigeon, Robert wrote: >Good day, > I have a question about the utilization of FITS format. I have >Mathematica 4.2 for Students and I'm trying to display and analyze those >images. Since 4.2 is suppose to have added the FITS format to the list of >recognized formats how come I cannot use the standard functions to view and >manipulate them? > I use > image=Import["m22.fits"]; > Then > Show[image] >It does not display anything! >I bought the add-on Digital Image Processing (1.1) and again I cannot use >any of the functions in that package. > >In a nut shell: I thought that FITS format could be used the same way a JPEG >format or any image (pic) format is used (displayed,manipulated,analyzed). > >Am I doing something wrong or maybe I did not understand something about >this new feature in Mathematica 4.2? > >Robert Pigeon While many people think of FITS as an image format, it is actually a data format. So the output of Import is data. In[1]:= data=Import["cb.fits"]; The data is a list of matrices. The length of the data will tell you how many matrices there are: In[2]:= Length[data] Out[2]= 1 The data in each matrix usually represents an intensity. You can then use a variety of functions to plot one of the matrices. ListDensityPlot is what you see in many FITS viewers. In[3]:= ListDensityPlot[First[data], Mesh->False] -DensityGraphics- In[4]:= ListContourPlot[First[data]] Out[4]= -ContourGraphics- In[5]:= ListPlot3D[First[data], Mesh->False] Out[5]= -SurfaceGraphics- -Dale