# conf.limits.nc.chisq: Confidence limits for noncentral chi square parameters In MBESS: The MBESS R Package

 conf.limits.nc.chisq R Documentation

## Confidence limits for noncentral chi square parameters

### Description

Function to determine the noncentral parameter that leads to the observed `Chi.Square`-value, so that a confidence interval for the population noncentral chi-squrae value can be formed.

### Usage

```conf.limits.nc.chisq(Chi.Square=NULL, conf.level=.95, df=NULL,
alpha.lower=NULL, alpha.upper=NULL, tol=1e-9, Jumping.Prop=.10)
```

### Arguments

 `Chi.Square` the observed chi-square value `conf.level` the desired degree of confidence for the interval `df` the degrees of freedom `alpha.lower` Type I error for the lower confidence limit `alpha.upper` Type I error for the upper confidence limit `tol` tolerance for iterative convergence `Jumping.Prop` Value used in the iterative scheme to determine the noncentral parameters necessary for confidence interval construction using noncentral chi square-distributions (`0 < Jumping.Prop < 1`)

### Details

If the function fails (or if a function relying upon this function fails), adjust the `Jumping.Prop` (to a smaller value).

### Value

 `Lower.Limit` Value of the distribution with `Lower.Limit` noncentral value that has at its specified quantile `Chi.Square` `Prob.Less.Lower` Proportion of cases falling below `Lower.Limit` `Upper.Limit` Value of the distribution with `Upper.Limit` noncentral value that has at its specified quantile `Chi.Square` `Prob.Greater.Upper` Proportion of cases falling above `Upper.Limit`

### Author(s)

Ken Kelley (University of Notre Dame; KKelley@ND.Edu); Keke Lai (University of California–Merced)

`conf.limits.nct`, `conf.limits.ncf`

### Examples

```# A typical call to the function.
conf.limits.nc.chisq(Chi.Square=30, conf.level=.95, df=15)

# A one sided (upper) confidence interval.
conf.limits.nc.chisq(Chi.Square=30, alpha.lower=0, alpha.upper=.05,
conf.level=NULL, df=15)
```

MBESS documentation built on Sept. 19, 2022, 5:05 p.m.