# PERIODIZE is the jOceans module of jLab.

``` PERIODIZE  Returns a doubly periodic version of an input array.

[XP,YP,FP]=PERIODIZE(X,Y,F) takes the matrix F and forms a doubly-
periodic version FP, which will be 3*SIZE(F).

XP and YP are the new X and Y axes extended based on the delta-X and
delta-Y values within X and Y.  X and Y must both have uniform spacing.

[XE,YE,FP]=PERIODIZE(N,X,Y,F) only extends F periodically by N points,
so that FP is SIZE(F,1)+2*N by SIZE(F,2)+2*N.

[XE,YE,FP]=PERIODIZE(N,M,X,Y,F) extends F periodically by N points in
the X-direction, corresponding to the *columns* of F, and by M points
in the Y-direction, corresponding to the *rows* of F.

Thus in this case FP will be SIZE(F,1)+2*M by SIZE(F,2)+2*N.

F may have multiple higher dimensions, for example a third dimension
corresponding to time.  Only the first two dimensions are periodized.

For singly periodic versions, use PERIODIZE(0,M,F) or PERIODIZE(N,0,F).

[XP,YP,F1P,F2P,...,FKP]=PERIODIZE(...,X,Y,F1,F2,...,FK) also works,
and returns periodized versions of all the K arrays F1, F2,...,FK.

'periodize --t' runs a test.
'periodize --f' generates a sample figure.

Usage: [xp,yp,fp]=periodize(x,y,f);
[xp,yp,fp]=periodize(N,x,y,f);
[xp,yp,fp]=periodize(N,M,x,y,f);
__________________________________________________________________
This is part of JLAB --- type 'help jlab' for more information
(C) 2013--2015 J.M. Lilly --- type 'help jlab_license' for details
```