## skel_crp

Removes thickening of diagonal lines in RP.

### Syntax

```
y=skel_crp(x);
```

### Description

`y = skel_crp(x)` creates a new recurrence matrix `y` in which
all recurrence points of the recurrence matrix `x` are removed
which lead to a thickening of diagonal lines. Slubs, but also
block structures are removed in favour of the longest diagonal
lines (skeletonization). Whenever a diagonal line (starting
with the longest lines contained in the diagonal line length
histogram) encounters an adjacent diagonal line, this adjacent
line and – recursively – all its consecutive adjacent lines,
get deleted.

### Examples

```
a = sin(linspace(0,5*2*pi,100));
X = crp(a,2,5,.5,'nonorm','nogui');
Y = skel_crp(X);
nexttile
imagesc(X)
axis xy square
nexttile
imagesc(Y)
axis xy square
colormap([1 1 1; 0 0 0])
```

### See Also

### References

Kraemer, K. H., Marwan, N.: Border effect corrections for diagonal line based recurrence quantification analysis measures, Phys. Lett. A, 383, 2019.