Possible to make labels appear when hovering over a point in matplotlib

Question

I am using matplotlib to make scatter plots  Each point on the scatter plot is associated with a named object  I would like to be able to see the name of an object when I hover my cursor over the point on the scatter plot associated with that object  In particular  it would be nice to be able to quickly see the names of the points that are outliers  The closest thing I have been able to find while searching here is the annotate command  but that appears to create a fixed label on the plot  Unfortunately  with the number of points that I have  the scatter plot would be unreadable if I labeled each point  Does anyone know of a way to create labels that only appear when the cursor hovers in the vicinity of that point

User · Answer

From http   matplotlib sourceforge net examples event handling pick event demo html    from matplotlib pyplot import figure  show import numpy as npy from numpy random import rand   if 1    picking on a scatter plot  matplotlib collections RegularPolyCollection       x  y  c  s   rand 4  100      def onpick3 event           ind   event ind         print  onpick3 scatter    ind  npy take x  ind   npy take y  ind        fig   figure       ax1   fig add subplot 111      col   ax1 scatter x  y  100 s  c  picker True       fig savefig  pscoll eps       fig canvas mpl connect  pick event   onpick3   show      This recipe draws an annotation on picking a data point  http   scipy-cookbook readthedocs io items Matplotlib Interactive Plotting html   This recipe draws a tooltip  but it requires wxPython  Point and line tooltips in matplotlib

User · Answer

mplcursors worked for me  mplcursors provides clickable annotation for matplotlib  It is heavily inspired from mpldatacursor  https   github com joferkington mpldatacursor   with a much simplified API  import matplotlib pyplot as plt import numpy as np import mplcursors  data   np outer range 10   range 1  5    fig  ax   plt subplots   lines   ax plot data  ax set title  Click somewhere on a line  nRight-click to deselect  n                Annotations can be dragged     mplcursors cursor lines    or just mplcursors cursor    plt show

User · Answer

The other answers did not address my need for properly showing tooltips in a recent version of Jupyter inline matplotlib figure  This one works though   import matplotlib pyplot as plt import numpy as np import mplcursors np random seed 42   fig  ax   plt subplots   ax scatter  np random random  2  26    ax set title  Mouse over a point   crs   mplcursors cursor ax hover True   crs connect  add   lambda sel  sel annotation set text       Point        format sel target 0   sel target 1     plt show     Leading to something like the following picture when going over a point with mouse

User · Answer

mpld3 solve it for me  EDIT  CODE ADDED     import matplotlib pyplot as plt import numpy as np import mpld3  fig  ax   plt subplots subplot kw dict axisbg   EEEEEE    N   100  scatter   ax scatter np random normal size N                    np random normal size N                    c np random random size N                    s 1000   np random random size N                    alpha 0 3                   cmap plt cm jet  ax grid color  white   linestyle  solid    ax set title  Scatter Plot  with tooltips     size 20   labels     point  0   format i   1  for i in range N   tooltip   mpld3 plugins PointLabelTooltip scatter  labels labels  mpld3 plugins connect fig  tooltip   mpld3 show     You can check this example

User · Answer

If you use jupyter notebook  my solution is as simple as    pylab import matplotlib pyplot as plt import mplcursors plt plot      mplcursors cursor hover True  plt show     YOu can get something like

User · Answer

This solution works when hovering a line without the need to click it   import matplotlib pyplot as plt    Need to create as global variable so our callback on plot hover  can access fig   plt figure   plot   fig add subplot 111     create some curves for i in range 4         Giving unique ids to each data member     plot plot           i 1 i 2 i 3 i 4           gid i   def on plot hover event         Iterating over each data member plotted     for curve in plot get lines              Searching which data member corresponds to current mouse position         if curve contains event  0               print  over  s    curve get gid    fig canvas mpl connect  motion notify event   on plot hover             plt show

User · Answer

A slight edit on an example provided in http   matplotlib org users shell html   import numpy as np import matplotlib pyplot as plt  fig   plt figure   ax   fig add subplot 111  ax set title  click on points    line    ax plot np random rand 100    -   picker 5     5 points tolerance   def onpick event       thisline   event artist     xdata   thisline get xdata       ydata   thisline get ydata       ind   event ind     print  onpick points     zip xdata ind   ydata ind      fig canvas mpl connect  pick event   onpick   plt show     This plots a straight line plot  as Sohaib was asking

User · Answer

I have made a multi-line annotation system to add to  https   stackoverflow com a 47166787 10302020  for the most up to date version  https   github com AidenBurgess MultiAnnotationLineGraph  Simply change the data in the bottom section   import matplotlib pyplot as plt   def update annot ind  line  annot  ydata       x  y   line get data       annot xy    x ind  ind   0    y ind  ind   0          Get x and y values  then format them to be displayed     x values       join list map str  ind  ind          y values       join str ydata n   for n in ind  ind        text            format x values  y values      annot set text text      annot get bbox patch   set alpha 0 4    def hover event  line info       line  annot  ydata   line info     vis   annot get visible       if event inaxes    ax            Draw annotations if cursor in right position         cont  ind   line contains event          if cont              update annot ind  line  annot  ydata              annot set visible True              fig canvas draw idle           else                Don t draw annotations             if vis                  annot set visible False                  fig canvas draw idle     def plot line x  y       line    plt plot x  y  marker  o         Annotation style may be changed here     annot   ax annotate     xy  0  0   xytext  -20  20   textcoords  offset points                           bbox dict boxstyle  round   fc  w                            arrowprops dict arrowstyle  - gt         annot set visible False      line info    line  annot  y      fig canvas mpl connect  motion notify event                              lambda event  hover event  line info       Your data values to plot x1   range 21  y1   range 0  21  x2   range 21  y2   range 0  42  2    Plot line graphs fig  ax   plt subplots   plot line x1  y1  plot line x2  y2  plt show

User · Answer

It seems none of the other answers here actually answer the question  So here is a code that uses a scatter and shows an annotation upon hovering over the scatter points   import matplotlib pyplot as plt import numpy as np  np random seed 1   x   np random rand 15  y   np random rand 15  names   np array list  ABCDEFGHIJKLMNO    c   np random randint 1 5 size 15   norm   plt Normalize 1 4  cmap   plt cm RdYlGn  fig ax   plt subplots   sc   plt scatter x y c c  s 100  cmap cmap  norm norm   annot   ax annotate     xy  0 0   xytext  20 20  textcoords  offset points                       bbox dict boxstyle  round   fc  w                        arrowprops dict arrowstyle  - gt     annot set visible False   def update annot ind        pos   sc get offsets   ind  ind   0       annot xy   pos     text            format     join list map str ind  ind                                       join  names n  for n in ind  ind          annot set text text      annot get bbox patch   set facecolor cmap norm c ind  ind   0          annot get bbox patch   set alpha 0 4    def hover event       vis   annot get visible       if event inaxes    ax          cont  ind   sc contains event          if cont              update annot ind              annot set visible True              fig canvas draw idle           else              if vis                  annot set visible False                  fig canvas draw idle    fig canvas mpl connect  motion notify event   hover   plt show       Because people also want to use this solution for a line plot instead of a scatter  the following would be the same solution for plot  which works slightly differently     x000D   x000D  import matplotlib pyplot as plt x000D  import numpy as np  np random seed 1  x000D   x000D  x   np sort np random rand 15   x000D  y   np sort np random rand 15   x000D  names   np array list  ABCDEFGHIJKLMNO    x000D   x000D  norm   plt Normalize 1 4  x000D  cmap   plt cm RdYlGn x000D   x000D  fig ax   plt subplots   x000D  line    plt plot x y  marker  o   x000D   x000D  annot   ax annotate     xy  0 0   xytext  -20 20  textcoords  offset points   x000D                      bbox dict boxstyle  round   fc  w    x000D                      arrowprops dict arrowstyle  - gt     x000D  annot set visible False  x000D   x000D  def update annot ind   x000D      x y   line get data   x000D      annot xy    x ind  ind   0    y ind  ind   0    x000D      text            format     join list map str ind  ind        x000D                                 join  names n  for n in ind  ind      x000D      annot set text text  x000D      annot get bbox patch   set alpha 0 4  x000D   x000D   x000D  def hover event   x000D      vis   annot get visible   x000D      if event inaxes    ax  x000D          cont  ind   line contains event  x000D          if cont  x000D              update annot ind  x000D              annot set visible True  x000D              fig canvas draw idle   x000D          else  x000D              if vis  x000D                  annot set visible False  x000D                  fig canvas draw idle   x000D   x000D  fig canvas mpl connect  motion notify event   hover  x000D   x000D  plt show   x000D   x000D   x000D    In case someone is looking for a solution for lines in twin axes  refer to How to make labels appear when hovering over a point in multiple axis   In case someone is looking for a solution for bar plots  please refer to e g  this answer

User · Answer

showing object information in matplotlib statusbar  Features  no extra libraries needed clean plot no overlap of labels and artists supports multi artist labeling can handle artists from different plotting calls  like scatter  plot  add patch  code in library style  Code     imports import matplotlib as mpl import matplotlib pylab as plt import numpy as np     https   stackoverflow com a 47166787 7128154   https   matplotlib org 3 3 3 api collections api html matplotlib collections PathCollection   https   matplotlib org 3 3 3 api path api html matplotlib path Path   https   stackoverflow com questions 15876011 add-information-to-matplotlib-navigation-toolbar-status-bar   https   stackoverflow com questions 36730261 matplotlib-path-contains-point   https   stackoverflow com a 36335048 7128154 class StatusbarHoverManager       quot  quot  quot      Manage hover information for mpl axes Axes object based on appearing     artists       Attributes     ----------     ax   mpl axes Axes         subplot to show status information     artists   list of mpl artist Artist         elements on the subplot  which react to mouse over     labels   list  list of strings  or strings         each element on the top level corresponds to an artist          if the artist has items          i e  second return value of contains   has key  ind            the element has to be of type list          otherwise the element if of type string     cid   to reconnect motion notify event      quot  quot  quot      def   init   self  ax           assert isinstance ax  mpl axes Axes            def hover event               if event inaxes    ax                  return             info    x    2f   y    2f   format event xdata  event ydata              ax format coord   lambda x  y  info         cid   ax figure canvas mpl connect  quot motion notify event quot   hover           self ax   ax         self cid   cid         self artists              self labels           def add artist labels self  artist  label           if isinstance artist  list               assert len artist     1             artist   artist 0           self artists     artist          self labels     label           def hover event               if event inaxes    self ax                  return             info    x    2f   y    2f   format event xdata  event ydata              for aa  artist in enumerate self artists                   cont  dct   artist contains event                  if not cont                      continue                 inds   dct get  ind                   if inds is not None     artist contains items                     for ii in inds                          lbl   self labels aa  ii                          info         artist    d     d         format                              aa  ii  lbl                  else                      lbl   self labels aa                      info         artist    d         format aa  lbl              self ax format coord   lambda x  y  info          self ax figure canvas mpl disconnect self cid          self cid   self ax figure canvas mpl connect               quot motion notify event quot   hover     def demo StatusbarHoverManager        fig  ax   plt subplots       shm   StatusbarHoverManager ax       poly   mpl patches Polygon            0 0    3  5    5  4    6 1    closed True  color  green   zorder 0      artist   ax add patch poly      shm add artist labels artist   polygon        artist   ax scatter  2 5  1  2  3    6  1  1  7   c  blue   s 10  2      lbls     point     str ii  for ii in range 4       shm add artist labels artist  lbls       artist   ax plot           0  0  1  5  3    0  1  1  0  2   marker  o   color  red       lbls     segment     str ii  for ii in range 5       shm add artist labels artist  lbls       plt show       --- main if   name      quot   main   quot       demo StatusbarHoverManager

[python] Possible to make labels appear when hovering over a point in matplotlib?

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