EP TM - T test - Each Point

(10/08/00)

PURPOSE

Computes the t-test values for each point in the average image/volume (resulting from adding an image/volume series) versus specified values. This operation tests whether the average image is significantly different from assumed values, for example whether values in the average image differ from zero.   Example.

SEE ALSO

AS R [Average image/volume series, optional subset]
EP [Error Probability]
EP TT [T test]

USAGE

.OPERATION: EP TM

.AVERAGE FILE: AVE001
[Enter name of the file containing the average of an image series. This can be obtained from operation 'AS R'.]

.VARIANCE FILE: VAR001
[Enter name of the file containing the variance of an image series. This can be obtained from operation 'AS R'.]

.NUMBER OF IMAGES AVERAGED: 56
[Enter the number of images added when the average image was formed.]

.TESTED POPULATION MEAN: ARF001
[Enter value of population mean.]

.SIGNIFICANCE IMAGE: SIG001
[Enter the name of the file which will contain the statistical significance of the point-by-point differences.]

NOTES

  1. For an elementary introduction into the theory of statistical inference, see (e.g.) P. Armitage, "Statistical Methods in Medical Research", Blackwell Scientific Publications, p99ff.

  2. Since the correct normalization of EM images is usually unknown the results of t-test should be taken with a grain of salt.

  3. Implemented by: P. Penczek.

SUBROUTINES

TTEST1

CALLER

CONF1

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