Question

我想学习如何从FITS文件头中获取信息并将该信息传输到ascii表。例如，这就是我获取信息的方式。：

    python
    import pyfits
    a = pyfits.open('data.fits')
    header = a[0].header # Which should return something like this (It is  BinHDUlist)
    SIMPLE  =                T / conforms to FITS standards                    
                               / institution responsible for creating this file 
TELESCOP= 'Kepler  '           / telescope                                      
INSTRUME= 'Kepler Photometer'  / detector type                                  
OBJECT  = 'KIC 8631743'        / string version of KEPLERID                     
RA_OBJ  =           294.466516 / [deg] right ascension                          
DEC_OBJ =            44.751131 / [deg] declination

如何创建包含RA_OBJ和DEC_OBJ的ASCII表？

编辑：我想创建一个包含标题中两列（RA和DEC）的.dat文件。这是我正在尝试的一个例子：

import asciitable
import asciidata
imort pyfits
import numpy as np

# Here I have taken all the fits files in my current directory and did the following:
# ls > z.txt so that all the fits files are in one place.

a = asciidata.open('z.txt')
i = 0 #There are 371 fits files in z.txt
while i<=370:
    b = pyfits.open(a[0][i])
    h = b[0].header
    RA = np.array([h['RA_OBJ']])
    DEC = np.array(h['DEC_OBJ']])
    asciitable.write({'RA': RA, 'DEC': DEC}, 'coordinates.dat', names=['RA', 'DEC'])
    i = i+1

我想为此编写一个包含以下内容的.dat文件：

RA    DEC
###   ###
...   ...
...   ...
...   ...

相反，我的代码只是写了以前文件的键。有什么想法吗？

Answer 1

我认为你可能会更仔细地阅读the pyfits documentation。 header属性是一个pyfits.header.Header对象，它是一个类似字典的对象。所以你可以这样做：

import pyfits

keys = ['SIMPLE', 'TELESCOP', 'INSTRUME', 'OBJECTS', 'RA_OBJ', 'DEV_OBJ']

hdulist = pyfits.open("data.fits")
header = hdulist[0].header
for k in keys:
    print k, "=", header[k]

您可以添加更多花哨的输出，将结果字符串放入变量，检查缺失的键等等。

修改：

以下是asciitable和numpy：
的结合方式
import asciitable import numpy as np keys = ['RA', 'DEC'] data = {} # Initialize "data" with empty lists for each key for k in keys: data[k] = [] # Collect all data in the "data" dictionary for i in range(0, 50): data['RA'].append(np.array(i)) data['DEC'].append(np.array(i+1)) asciitable.write(data, "coords.dat", names=keys)

从FITS文件头创建Ascii表

1 个答案: