$xgradualdiv

This function is to determine how the segment is divided. There are two columns to fill in. The first column i should be filled in an integer 0, 1, or 2.

i = 0:	Uniform. This means the segment is divided equally with the same spacing.
i = 1:	Gradual. This means the segment is divided whether from small spacing to large spacing or in the opposite way. The spacing is distributed like a geometric progression
i = 2:	Bump. This means the segment can be divided into two forms small-large-small or large-small-large.

The second column r should be filled in a real number.

	If r < 1	If r = 1	If r > 1
Uniform (0)	uniform	uniform	uniform
Gradual (1)	large -> small	uniform	small -> large
Bump (2)	large -> small -> large	uniform	small -> large -> small

If the total layer thickness is $l$ and i=1, then if the smallest separation distance is a 
$l = a+ar+ar^{2}+ar^{3}+ar^{4}+...+ar^{N}$
where N is the total grid number defined in $xdiv
Then   $l = a\frac{r^{N}-1}{r-1}$

If the total layer thickness is $l$ and i=2, then if the smallest separation distance is a 
$l/2 = a+ar+ar^{2}+ar^{3}+ar^{4}+...+ar^{N/2}$
where N is the total grid number defined in $ydiv
Then   $l = 2 \cdot a\frac{r^{N/2}-1}{r-1}$

Example

$xnode
0.0
20.0
40.0
60.0

$xdiv
30 
70 
80

$xgradualdiv
0 
1 1.1
2 0.95

Related commands

$ygradualdiv , $xnode,$xdiv