org.strbio.math
Class FBin

java.lang.Object
  org.strbio.math.IVector
      org.strbio.math.FBin

public class FBin
extends IVector

a class which does 1-D histogram-FBins. If you're sampling some (float) data and want stats like average, stdev on the ensemble, but don't want to bother keeping track of every point, this should be useful. If you do want to keep track of every point, try using a DVector or DMatrix, which have similar stats functions.

 Version 1.2, 6/24/99 - added main() to sample from a file.
 Version 1.1, 9/29/98 - sample()
   is no longer final, and PrintfStream changed to Printf.
   Fixed average and stdev to return NaN when not enough samples.
   Sample() now returns an int, indicating the FBin it was put
   into.
 Version 1.0, 3/31/98 - original version.
 

Version:

1.2, 6/24/99

Author:

JMC

Field Summary

protected float	FBinsize
protected float	min_v
protected int	nsamples
protected float	sum_x
protected float	sum_x2

Fields inherited from class org.strbio.math.IVector

data

Constructor Summary

FBin(int nFBins, float minv, float maxv)
to set up the histogram-FBin, you need to know the number of FBins you want, the minimum possible value, and the maximum possible value of the data.

Method Summary

float	average() Return the average of all values sampled.
void	print(Printf outfile) print out FBins to an open Printf.
void	print(java.lang.String filename) print out FBins to a new file.
int	sample(float r) Sample a value.
int	samples() how many values have I sampled?
float	stdev() Return the standard deviation of all values sampled.

Methods inherited from class org.strbio.math.IVector

add, add, cross, cross, dimension, dot, dot, eliminate, equals, length, load, load, max, min, multiply, multiply, multiply, reverse, reverse, save, save, setValue, setValueAt, sort, subtract, subtract, valueAt

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

min_v

protected float min_v

FBinsize

protected float FBinsize

sum_x

protected float sum_x

sum_x2

protected float sum_x2

nsamples

protected int nsamples

Constructor Detail

FBin

public FBin(int nFBins,
            float minv,
            float maxv)

to set up the histogram-FBin, you need to know the number of FBins you want, the minimum possible value, and the maximum possible value of the data. Sorry, but dynamically expanding FBins would be a pain in the ass to write.

Parameters:

nFBins - the number of FBins to sort data into. You don't need any FBins at all if you just want stats like average, stdev.

minv - the minimum data you might sample

maxv - the maximum data you might sample

Method Detail

sample

public int sample(float r)

Sample a value. If the value is lower than the minimum value you specified in setting up the FBin, the sample goes into the lowest FBin. Same thing goes for the high end. This 'rounding off' does not affect statistics like the average.

average

public final float average()

Return the average of all values sampled.

stdev

public final float stdev()

Return the standard deviation of all values sampled. This is the 'sample' standard deviation.

samples

public final int samples()

how many values have I sampled?

print

public void print(Printf outfile)
           throws java.io.IOException

print out FBins to an open Printf. For each FBin, this prints the min, center, and maximum bounds of the FBin, and the number of values that were sampled in it.

Overrides:

print in class IVector

Throws:

java.io.IOException

See Also:

IVector.save(org.strbio.io.Printf)

print

public final void print(java.lang.String filename)
                 throws java.io.IOException

print out FBins to a new file. For each FBin, this prints the min, center, and maximum bounds of the FBin, and the number of values that were sampled in it.

Parameters:

filename - the file name. Overwrites existing files.

Throws:

java.io.IOException