− | To understand the concept of a volume of data, think of a room. Imagine the room divided up into points, each, say, one foot apart. Any particular point will have an (''x, y, z'') coordinate and a data value. The coordinate is the distance from a particular corner of the ceiling. We choose the ceiling so that ''z'' points down into the room. At any given point the data value is, say, the temperature, so we have temperature as a function of (''x, y, z''). As we move around the room to other points, the temperature changes—high near incandescent lights and low near a glass of ice water. | + | To understand the concept of a volume of data, think of a room. Imagine the room divided up into points, each, say, one foot apart. Any particular point will have an (''x, y, z'') coordinate and a data value. The coordinate is the distance from a particular corner of the ceiling. We choose the ceiling so that ''z'' points down into the room. At any given point adata value (e.g., temperature) can be measured, so we have temperature as a function of (''x, y, z''). As we move around the room to other points, the temperature changes — high near incandescent lights and low near a glass of ice water. |
| * The vertical axis is vertical reflection time, not depth. | | * The vertical axis is vertical reflection time, not depth. |