Then, I set the bottom axis label angle to 90 degree.
So every label in the horizontal axis is displayed in 90 degree.
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Since I only want line series's label been displayed, so created a custom axes and set bubble series horizotal axis to this custom axes.
Then, I set that custom axis label to 0 degree.
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As shown in the picture, the bubble series label is displayed in 0 degree but the space under the horizontal axis is still allocated for that label as it displayed in 90 degree.
I uncheck the label visible box.
But the space is still there.
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I also set that custom axis label style to None, but the space is still there.
The space size is determined by the length of the text in the bubble series data.
Any idea on how to remove those extra spaces?