chi2CMB: Chi-squared statistic for two 'CMBWindow's

In frycast/rcosmo: Cosmic Microwave Background Data Analysis

Chi-squared statistic for two CMBWindows

Description

This function returns the empirical chi-squared statistic for intensities observations from two CMBWindows of the specified CMBDataFrame. The functions employs the function chi2.empirical and uses histogram counts of intensities for computations.

Usage

chi2CMB(cmbdf, win1, win2, intensities = "I")

Arguments

cmbdf	A CMBDataFrame.
win1	A CMBWindow
win2	A CMBWindow
intensities	A CMBDataFrame column with measured values.

Value

Estimated Chi-squared statistic for observations in two CMBWindows. For small sample sizes and many zero counts Chi-squared statistic is inefficient.

References

chi2.empirical

Examples

## Download the map first
# downloadCMBMap(foreground = "smica", nside = 1024)
# df <- CMBDataFrame("CMB_map_smica1024.fits")
# cmbdf <- sampleCMB(df, sample.size = 1000)
#
# win1 <- CMBWindow(theta = c(0,pi/2,pi/2), phi = c(0,0,pi/2))
# win2 <- CMBWindow(theta = c(pi/2,pi,pi/2),  phi = c(0,0,pi/2))
# plot(win1)
# plot(win2,col="green")
#
# chi2CMB(cmbdf, win1, win2)

frycast/rcosmo documentation built on Oct. 11, 2022, 5:21 p.m.