A diagram drawn by considering only one characteristic of the data is called one-dimensional diagram.

The types of one dimensional diagrams are four :

1. Bar diagram: It is used to represent the data on different places, things or times. To draw bar diagram, the different places, things or times are taken on X-axis and the measure of respective places, things or time on Y-axis with appropriate scale. Bars with equal width at equal distance are drawn with the height proportional to the measure. The diagram formed in such manner is called bar diagram.

In bar diagram the logical order of bars should be maintained. To make comparative study easy, the bars showing places or things should be arranged in proper order on the graph but the bars showing times are presented as it is on graph paper.

2. Multiple or adjacent bar diagram: When the data about different places, things or times are collected on more than one mutually related characteristics, then multiple bar diagram is drawn by placing the related bars close to each other. If the data given are related to time, then bars are drawn in order of, time but when the data are not related to time then they are arranged in ascending or descending order of any one of the characteristics of the data.

3. Simple divided bar diagram: If the data on different places, things or times consist of several mutually related sub-data on different components are given then simple divided bar diagram is drawn.
In this diagram first of all a bar of proper width and height proportional to the total value of the data is drawn. Then it is divided in accordance with the sub-data into different segments by various signs.

4. Percentage divided bar diagram: In simple divided bar diagram the mutually related sub-data cannot be effectively compared. To overcome this difficulty, percentage divided bar diagram is drawn.

In this diagram taking the total value of data as 100%, the percentages of sub-data are calculated. A bar of appropriate width and height proportional to 100% is drawn and is divided in accordance with the percentage of sub-data. By such diagram the mutually related sub-data can be effectively compared but the total value cannot be compared.