# GjincBeam

From CASA Guides

**Return to Analysis Utilities**

This page documents the gjincBeam function of the Python module analysisUtils.

This function calls the gjinc class to compute the effective restoring beam obtained from the casa command sd_imaging when using the GJINC gridding kernel assuming the GJINC specific parameters are left at their default values. It returns the value in arc seconds.

## Usage

au.gjincBeam(frequency, pixelsize=10, diameter=12.0, samplingFactor=2.5)

frequency: floating point number in GHz (no units) pixelsize: floating point number in arcseconds (no units) diameter: the diameter of the single dish antenna in meters (no units) xSamplesPerBeam: the number of sampled points per telescope FWHM beam along the X axis ySamplesPerBeam: the number of sampled points per telescope FWHM beam along the Y axis xSamplingArcsec: if not None, then use this value instead of xSamplesPerBeam ySamplingArcsec: if not None, then use this value instead of ySamplesPerBeam

## Examples

```
CASA <3>: au.gjincBeam(115.27)
Theoretical primary beam FWHP = 52.3039 arcsec
Sampled every 10.4608 arcsec (5.000000 points per beam)
Expected effective restoring beam = 54.2091 arcsec
Out[3]: 54.209121599085897
CASA <5>: au.gjincBeam(115.27, xSamplingArcsec=10, ySamplingArcsec=15)
Theoretical primary beam FWHP = 52.3039 arcsec
Sampled every 10 arcsec (5.23039 points per beam) in X
Sampled every 15 arcsec (3.48693 points per beam) in Y
Expected effective restoring beam along X = 54.1741 arcsec
Expected effective restoring beam along Y = 54.5878 arcsec
Geometric mean = 54.3805 arcsec
Out[5]: 54.380521837034024
```