minorticks cannot be setted in colorbar

[cmyangcn]

The minorticks cannot be correctly setted in the colorbar.

m=ax.contourf(x1,t1,z,levels=np.linspace(0,500,200),extend='both')
ax.colorbar(m,ticks=np.arange(0,501,100),minorticks=20)

The minorticks in the plot are not 20, but depend on the "levels".

[cvanelteren]

Hi there, thanks for reporting. Please provide a minimal reproducible example -- it is hard to tell what the intentions are based on the snippets.

I had a quick peek at the code to see what's going on. The levels will set the space of colors that you can extract from the contourf whereas the ticker on the colorbar will subdivide this space. For example

import ultraplot as plt
import numpy as np


x = np.random.rand(10, 10)
fig, ax = plt.subplots()
ticks = np.linspace(0, 10)
y = np.array([0, 2, 10])
m = ax.contourf(x, x, x, levels=y, extend="both")
cb = ax.colorbar(m)
fig.show()

will produce a plot in which the levels are indicated by y which will generate a colorbar with 3 levels.

If I would then set the ticks, it will attempt to fill the range set by levels, e.g.

x = np.random.rand(10, 10)
fig, ax = plt.subplots()
ticks = np.linspace(0, 10)
y = np.array([0, 2, 10])
m = ax.contourf(x, x, x, levels=y, extend="both")
cb = ax.colorbar(m, ticks = ticks)
fig.show()

This is behaving a it should I think, but I could be misinterpreting what you mean.

[cmyangcn]

Thank you! Take the demo in the documentation as an example (https://ultraplot.readthedocs.io/en/latest/colorbars_legends.html#Figure-wide-colorbars-and-legends).

import ultraplot as uplt
import numpy as np

state = np.random.RandomState(51423)
fig, axs = uplt.subplots(ncols=3, nrows=3, refwidth=1.4)
for ax in axs:
    m = ax.pcolormesh(
        state.rand(20, 20), cmap="grays", levels=np.linspace(0, 1, 11), extend="both"
    )
fig.format(
    suptitle="Figure colorbars and legends demo",
    abc="a.",
    abcloc="l",
    xlabel="xlabel",
    ylabel="ylabel",
)
#fig.colorbar(m, label="column 1", ticks=0.5, loc="b", col=1)
#fig.colorbar(m, label="columns 2 and 3", ticks=0.2, loc="b", cols=(2, 3))
fig.colorbar(m, label="stacked colorbar", ticks=0.1, loc="b", minorticks=0.05)
#fig.colorbar(m, label="colorbar with length <1", ticks=0.1, loc="r", length=0.7)

The minorticks in the colorbar of the figure is not 0.05, but 0.1, as showing in the following image. When I use proplot, it's correct.

[cvanelteren]

Can you checkout the PR

pip install git+https://github.com/cvanelteren/ultraplot.git@locator-fix

[cmyangcn]

The changes in the locator-fix branch resolve the issue effectively.

[cvanelteren]

Fixed in main.