contour plot with positive/negative values - how to set the line style for (negative) dashed values

[Alessandro Mandelli]

Alessandro Mandelli wrote:

> Use cmin 0 for plotting with solid line (set line color# <style>
> <thickness> with style = 1)
> Use cmax 0 for plotting with dashed or other color line (set line color#
> <style> <thickness> with style = 3 or 5)

That was for lines. For contours use cstyle.