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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[ENH]: Voxels as mappable for colorbar","articleBody":"### Problem\n\nHi;\r\n\r\nI'm working with 3D plots and I use colored voxels to plots a 4th dimension.\r\n\r\nWhen one wants to use a colorbar, one usually uses an image or a contourf in the colorbar creation method like so : \r\n\r\n```\r\nimg = ax.imshow(event, **cmap_args)\r\nplt.colorbar(img)\r\n```\r\n\r\nIt is very handful to handle all the colormap arguments (such as vmin etc) directly from the image but doesn't work with voxels.\r\n\r\n\r\nCurrently I use this : \r\n\r\n\r\n`\r\n\r\n    palette=mpl.cm.get_cmap(\"viridis\",lut=levels).copy()     #simulate the level arg of other plot methods\r\n    palette.set_under((0,0,0,0))                             #So vmin has an effect\r\n    if add_colorbar:\r\n    \r\n    vmax = np.max(NPArr)                                    #NPArr is the data being plotted\r\n    norm = mpl.colors.Normalize(0,vmax)                     #Necessary because there is no mappable from voxels, instead of normalizing the data it is easier to normalize the \"cmap\"\r\n    m = cm.ScalarMappable(cmap=palette,norm=norm)           #Creates Mappable\r\n    m.set_array([])                                         #Makes it the right type so get() methods exist\r\n    ticks = np.linspace(1,vmax,levels+1)\r\n    fig.colorbar(m, ax=ax, extend=\"min\", ticks=ticks)       #Finally creates the cmap with other cmap arguments that can't be passed to the mappable\r\n\r\n`\r\n\r\n\r\nVoxels give dictionnary of 3d objet so I have tried to use one of its value as mappable which works but doesn't bring all the data info for the colormap.\n\n### Proposed solution\n\n_No response_","author":{"url":"https://github.com/Luluser","@type":"Person","name":"Luluser"},"datePublished":"2022-05-04T11:35:52.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":13},"url":"https://github.com/22969/matplotlib/issues/22969"}