Piirakkadiagrammit

Piirakkadiagrammit, also known as pie charts, are a type of data visualization that represents categorical data as a circle divided into slices. Each slice's size is proportional to the quantity it represents. This makes them useful for showing proportions of a whole.

The total area of the circle represents 100% of the data. The angle of each slice corresponds to the percentage of the whole that category accounts for. For example, if a pie chart shows the results of a survey on favorite fruits, and apples are chosen by 50% of respondents, the slice representing apples would occupy half of the circle.

Pie charts are best suited for displaying a small number of categories, typically no more than five or six. When too many slices are present, the chart can become cluttered and difficult to interpret. They are also most effective when the data clearly shows one or two dominant categories. Comparing the sizes of slices can be challenging, especially if they are very similar.

While commonly used, pie charts have limitations. They are not ideal for comparing the exact values of different categories, as our eyes are not good at accurately judging angles. For detailed comparisons, bar charts or other graphical representations might be more appropriate. Nevertheless, pie charts remain a popular and easily understandable way to illustrate simple proportions at a glance.