SDM calculations

Descriptive analyses of quartiles

This procedure calculates meta-analytic quantiles. You can specify a filter for subgroup analyses. The following quantiles are automatically calculated with the graphical interface:

- 25: first quartile, i.e. a quarter of the studies have lower values (and three quarters of the studies have higher values).

- 50: median (second quartile), i.e. half of the studies have lower values (and half of the studies have higher values).

- 75: third quartile, i.e. three quarters of the studies have lower values (and a quarter of the studies have higher values).

To calculate quartiles

Press the button [Quartiles]

or:

Select [Quartiles] in the Statistics menu, to open the following dialog:

Command-line and batch usage

quantile quantile, filter

Example:

MedianMap = quantile 0.5

References

Radua J and Mataix-Cols D. Voxel-wise meta-analysis of grey matter changes in obsessive-compulsive disorder. Br J Psychiatry 2009; 195:393-402 .

The authors | IoP King's College London | NeuroImageN