anovaint {OLIN} | R Documentation |

## One-factorial ANOVA assessing intensity-dependent bias

### Description

This function performs an one-factorial analysis of variance assessing intensity-dependent bias
for a single array. The predictor variable is the average logged intensity of both channels
and the response variable is the logged fold-change.

### Usage

anovaint(obj,index,N=10)

### Arguments

`obj` |
object of class “marrayRaw” or “marrayNorm” |

`index` |
index of array to be tested |

`N` |
number of (intensity) levels for ANOVA |

### Details

The function `anovaint`

performs a one-factorial ANOVA for objects of class “marrayRaw” or
“marrayNorm”. The predictor variable is the average logged intensity of both channels
`A=0.5*(log2(Ch1)+log2(Ch2))`

. `Ch1,Ch2`

are the fluorescence intensities of channel 1
and channel 2, respectively. The response variable is the logged fold-change
`M=(log2(Ch2)-log2(Ch1))`

. The `A`

-scale is divided in `N`

intervals generating
`N`

levels of factor `A`

. Note that
`N`

should divide the total number of spots approx. equally.
The null hypothesis is the equality of `mean(M)`

of the different levels (intervals).
The model formula used is *M ~ (A - 1)* (without an intercept term).

### Value

The return value is a list of summary statistics of the fitted model as produced by `summary.lm`

.
For example, the squared multiple correlation coefficient *R-square* equals the proportion
of the variation of `M`

that can be explained by the variation of `A`

(based on the chosen
ANOVA model.)

### Author(s)

Matthias E. Futschik (http://itb.biologie.hu-berlin.de/~futschik)

### See Also

`anova`

, `summary.lm`

,
`anovaspatial`

, `marrayRaw`

, `marrayNorm`

### Examples

# CHECK RAW DATA FOR INTENSITY-DEPENDENT BIAS
data(sw)
print(anovaint(sw,index=1,N=10))
# CHECK DATA NORMALISED BY OLIN FOR INTENSITY-DEPENDENT BIAS
data(sw.olin)
print(anovaint(sw.olin,index=1,N=10))

[Package

*OLIN* version 1.3.2

Index]