The kmo_stats recipe

kmo_stats

Synopsis

Perform basic statistics on a KMOS-conform fits-file

Description

This recipe performs basic statistics on KMOS-conform data-frames of type F2D, F1I, F2I and F3I either with or without noise and RAW. Optionally a 2D mask can be provided to define a region on which the statistics should be calculated on (mask 0: exclude pixel, mask 1: include pixel). A mask can’t be provided for statistics on F1I frames.

The output is stored in a vector of length 11. The vector represents following values:

  1. Number of pixels
  2. Number of finite pixels
  3. Mean
  4. Standard Deviation
  5. Mean with iterative rejection (i.e. mean & sigma are calculated iterati- vely, each time rejecting pixels more than +/-N sigma from the mean)
  6. Standard Deviation with iterative rejection
  7. Median
  8. Mode (i.e. the peak in a histogram of pixel values)
  9. Noise (a robust estimate given by the standard deviation from the nega- tive side of the histogram of pixel values)
  10. Minimum
  11. Maximum

The same numerical operations are applied to the noise as with the data itself.

Input files

DO            DO      KMOS
category      group   Type   Explanation                    Required #Frames
--------      -----   -----  -----------                    -------- -------
<none or any>   -     F3I or The datacubes                      Y       1
                      F2I or
                      F1I or
                      F2D or
                      B2D or
                      RAW
<none or any>   -     F2I or The mask                           N      0,1
                      F2D or
                      B2D or
                      RAW

Output files

DO                    KMOS
category              Type   Explanation
--------              -----  -----------
STATS                 F1I    Calculated statistics parameters

Constructor

cpl.Recipe("kmo_stats")

Create an object for the recipe kmo_stats.

import cpl
kmo_stats = cpl.Recipe("kmo_stats")

Parameters

kmo_stats.param.ext

The extension the stats should be calculated of. Zero is default and calculates the stats of all extensions (int; default: 0) [default=0].

kmo_stats.param.cpos_rej

The positive rejection threshold for kappa-sigma-clipping (sigma). (float; default: 3.0) [default=3.0].

kmo_stats.param.cneg_rej

The negative rejection threshold for kappa-sigma-clipping (sigma). (float; default: 3.0) [default=3.0].

kmo_stats.param.citer

The number of iterations for kappa-sigma-clipping. (int; default: 3) [default=3].

The following code snippet shows the default settings for the available parameters.

import cpl
kmo_stats = cpl.Recipe("kmo_stats")

kmo_stats.param.ext = 0
kmo_stats.param.cpos_rej = 3.0
kmo_stats.param.cneg_rej = 3.0
kmo_stats.param.citer = 3

You may also set or overwrite some or all parameters by the recipe parameter param, as shown in the following example:

import cpl
kmo_stats = cpl.Recipe("kmo_stats")
[...]
res = kmo_stats( ..., param = {"ext":0, "cpos_rej":3.0})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

Please report any problems to Alex Agudo Berbel. Alternatively, you may send a report to the ESO User Support Department.