Use cone traces to visualize vector fields.  Specify a vector field using 6 1D arrays, 3 position arrays `x`, `y` and `z` and 3 vector component arrays `u`, `v`, `w`. The cones are drawn exactly at the positions given by `x`, `y` and `z`.

Determines whether or not the contour level attributes are picked by an algorithm. If *true*, the number of contour levels can be set in `ncontours`. If *false*, set the contour level attributes in `contours`.

Determines whether or not gaps (i.e. {nan} or missing values) in the `z` data are filled in. It is defaulted to true if `z` is a one dimensional array otherwise it is defaulted to false.

Determines the coloring method showing the contour values. If *fill*, coloring is done evenly between each contour level If *heatmap*, a heatmap gradient coloring is applied between each contour level. If *lines*, coloring is done on the contour lines. If *none*, no coloring is applied on this trace.

Sets the end contour level value. Must be more than `contours.start`

Sets the font used for labeling the contour levels. The default color comes from the lines, if shown. The default family and size come from `layout.font`.

Sets the contour label formatting rule using d3 formatting mini-languages which are very similar to those in Python. For numbers, see: https://github.com/d3/d3-format/tree/v1.4.5#d3-format.

Sets the constraint operation. *=* keeps regions equal to `value` *<* and *<=* keep regions less than `value` *>* and *>=* keep regions greater than `value` *[]*, *()*, *[)*, and *(]* keep regions inside `value[0]` to `value[1]` *][*, *)(*, *](*, *)[* keep regions outside `value[0]` to value[1]` Open vs. closed intervals make no difference to constraint display, but all versions are allowed for consistency with filter transforms.

Determines whether to label the contour lines with their values.

Determines whether or not the contour lines are drawn. Has an effect only if `contours.coloring` is set to *fill*.

Sets the step between each contour level. Must be positive.