The Bubble (2D) chart. How to control the drawing of circles
Hi All!
Challenge: You want to display three circles with diameters 1.0, 1.5 and 2.0. Using Bubble (2D) we get the following picture:
. Obviously, QM by default draws circles so that their areas are related as squares of diameters, which is true mathematically, but incorrect financially and economically.
Here’s how this problem looks, eg, in Tahir’ video on his YouTube channel:
. You see, the sales of the USA and Germany differ twice. But the areas is four times.
Q1: is it possible to force QM to draw circles so that their areas are visually perceived as relations of given diameters?
If you combine Bubble (2D) with geographical maps of countries, it is useful to display the centers of circles as well. This will make it easier for the user visually associate a particular circle with its country.
Q3: Is it possible to force QM to display of the bubbles’ centers? – My answer to Q3. Yes, its possible.
Here’s how my solution works:
*
*
Pay attention to the UK – center of the circle precisely points to the UK…
As you can see, QM makes it possible to implement more flexible custom Bubble (2D) control algorithms.
Good luck!
Displaying labels inside circles is not always visually appealing. In such cases it would be nice to be able, for example, vertically shift the output of labels.
Q2: Is it possible to force QM to display labels with a vertical offset? – My answer to Q2. Yes, its possible.
Here’s how my solution works:
*
*
Here my answer to Q1. Yes, its possible.
To do this, perform the following conversion of the original circles diameters:
1. from the list of source circles select one circle as the base circle and
2. use its diameter to express the diameters of all the circles in the list. The resulting list of converted circles diameters should be submitted for drawing.
See how it works:
*
*
Here’s how it works for Tahir’s case:
*
*
By the way, pay attention to the output of labels just above the center of the circle. Next time, I will demonstrate the vertical offset output of labels.
As a comparison here is the smaller version of Bubble (2D) chart on the world map. This copy is made entirely from scratch. QM did not present any difficulties in reducing the scale.
*
