Avoid annotations and tick y_tick labels overlapping

Question

I went through several questions but none seem to address the problem of annotations overlapping with y tick labels. I found a nice code that prevents annotations overlapping among themselves, but nothing with tick labels.

My problem is quite simple actually. I use the following lines to create the graph I paste just below them. I use annotate to show what the last value for both lines is. I set the position of the annotation based on the ratio of the last value to the total range of the y axis. It works pretty well except when the annotation overlaps the tick label. It is not that big a deal but it does not look nice when including the graph in a report.

Here is the code — I ommit the lines that manipulate the data:

x = MERVAL.index[(MERVAL.index >= '2014-01-01')]
y1 = MERVAL['MERVAL'][(MERVAL.index >= '2014-01-01')]
y2 = MERVAL['MERVAL_USD'][(MERVAL.index >= '2014-01-01')]
last_date = MERVAL.tail(1).index
right_limit = last_date + datetime.timedelta(days=30)
months = mdates.MonthLocator(1)
monthsFmt = mdates.DateFormatter('%m/%Y')
datemin = datetime.datetime.strptime('01/01/2014', '%m/%d/%Y')
f, ax = plt.subplots()
ax.plot(x,y1, color='b', linewidth=1, label='MERVAL')
ax2 = ax.twinx()
ax2.plot(x,y2, color='r', linewidth=1, label='MERVAL in USD')
ax.set_title('MERVAL',fontsize=20,color='green')
ax.xaxis.set_major_locator(months)
ax.xaxis.set_major_formatter(monthsFmt)
ax.set_xlim(left=datemin, right=right_limit)
ax2.set_xlim(left=datemin, right=right_limit)
ax.grid(axis='x', linestyle=':')
ax.legend(loc=(0.01,0.9))
ax2.legend(loc=(0.01,0.8))
bottom, top = ax.get_ylim()
bottom1, top1 = ax2.get_ylim()
MERVAL_last_price = MERVAL.iloc[-1,0]
MERVAL_USD_last_price = MERVAL.iloc[-1,1]
ax.annotate(str(MERVAL.iloc[-1,0].round(2)), xy=(0,(MERVAL.iloc[-1,0])), xytext=(-0.13 ,((MERVAL_last_price - bottom) / (top - bottom))), xycoords='axes fraction', color='b', annotation_clip=False)
ax2.annotate(str(MERVAL.iloc[-1,1].round(2)), xy=(1,(MERVAL.iloc[-1,1])), xytext=(1.01,((MERVAL_USD_last_price - bottom1) / (top1 - bottom1))), xycoords='axes fraction',color='r', annotation_clip=False)
plt.show()

Here is the graph. Highlighted in yellow what I would like to fix:

As noted in the comment below, I would like the red label to either be above (preferably since it's a higher number) or below the tick label). I know how to take it far to the right or to the left. I also know how to move it manually up or down. Is there a way to have Matplotlib check if it overlaps with the tick label and automatically move it up or down?

I think it's pretty clear that I'm trying to avoid the overlapping of the annotation with the y tick label, isn't it? — teoeme139, Jul 05 '19 at 21:04
Just editted the question. I would like it to be done automatically since I include several graphs like this one in reports and would save me the time of moving them manually. — teoeme139, Jul 05 '19 at 21:07
Ok, so the solution would be pretty similar to [this one](https://stackoverflow.com/a/10739207/4124317), except that you only have 1 label to account for (you can check if the annotation overlaps with two labels, in which case there is no solution possible). So if it overlaps, check if it needs to shift upwards or downwards, then shift it sequentially until it does not overlap any more. — ImportanceOfBeingErnest, Jul 05 '19 at 21:13
@ImportanceOfBeingErnest I read that post before posting but didn’t realize it could also be applied to tick labels. Will try. Thanks — teoeme139, Jul 05 '19 at 21:22
Well, it cannot directly be applied to the labels (because in your case they live in different coordinate systems), but understanding that post will help you find a solution for your case. For that matter it might be beneficial not to position the annotation in axes coordinates though. — ImportanceOfBeingErnest, Jul 05 '19 at 22:08
You might also think of other ways to show this information. The easiest would be to put it in the legend. Also relatively easy would be to put it inside the axes instead of on the side, perhaps with a rectangle background that has an alpha so you can still see any data this may hide. Third, if you want to be fancy, you can easily re-write the yaxis tick locator to include the last value and exclude any values that are too close to it. — Jody Klymak, Jul 05 '19 at 22:25
Thanks for the ideas Jody. Which coordinates would you use, @ImportanceOfBeingErnest ? Data coordinates? — teoeme139, Jul 08 '19 at 13:46

score 1 · Accepted Answer · answered Jul 08 '19 at 14:46

I thought it would be a good idea to complete the post with the solution I found thanks to the above comments. I went for the third option in Jody Klymak's comment.

I added a few lines to find what the y_ticks are, remove any ticks within a specific range around the last value, and finally set new y_ticks.

Updated code:

x = MERVAL.index[(MERVAL.index >= '2014-01-01')]
y1 = MERVAL['MERVAL'][(MERVAL.index >= '2014-01-01')]
y2 = MERVAL['MERVAL_USD'][(MERVAL.index >= '2014-01-01')]
last_date = MERVAL.tail(1).index
right_limit = last_date + datetime.timedelta(days=30)
months = mdates.MonthLocator(1)
monthsFmt = mdates.DateFormatter('%m/%Y')
datemin = datetime.datetime.strptime('01/01/2014', '%m/%d/%Y')
f, ax = plt.subplots()
ax.plot(x,y1, color='b', linewidth=1, label='MERVAL')
ax2 = ax.twinx()
ax2.plot(x,y2, color='r', linewidth=1, label='MERVAL in USD')
ax.set_title('MERVAL',fontsize=20,color='green')
ax.xaxis.set_major_locator(months)
ax.xaxis.set_major_formatter(monthsFmt)
ax.set_xlim(left=datemin, right=right_limit)
ax2.set_xlim(left=datemin, right=right_limit)
ax.grid(axis='x', linestyle=':')
ax.legend(loc=(0.01,0.9))
ax2.legend(loc=(0.01,0.8))
bottom, top = ax.get_ylim()
bottom1, top1 = ax2.get_ylim()
MERVAL_last_price = MERVAL.iloc[-1,0]
MERVAL_USD_last_price = MERVAL.iloc[-1,1]
ax.annotate(str(MERVAL.iloc[-1,0].round(2)), xy=(0,(MERVAL.iloc[-1,0])), xytext=(-0.13 ,((MERVAL_last_price - bottom) / (top - bottom))), xycoords='axes fraction', color='b', annotation_clip=False)
ax2.annotate(str(MERVAL.iloc[-1,1].round(2)), xy=(1,(MERVAL.iloc[-1,1])), xytext=(1.01,((MERVAL_USD_last_price - bottom1) / (top1 - bottom1))), xycoords='axes fraction',color='r', annotation_clip=False)
loc = ax2.get_yticks()
space = loc[1] - loc[0]
print(space)
new_loc = list()
for x in loc:
    if x <= MERVAL.iloc[-1,1] + space / 2 and x >= MERVAL.iloc[-1,1] - space / 2:
        new_loc.append('')
    else:
        new_loc.append(x)
ax2.set_yticklabels(new_loc)
plt.show()

Updated chart:

Avoid annotations and tick y_tick labels overlapping

1 Answers1