An automated weather buoy logs sea surface temperatures at regular intervals. The system uses an algorithm to calculate the temperature gradients between consecutive readings.
The pseudocode for this procedure is shown below.
1 PROCEDURE calculateTemperatureGradient()
2 BEGIN PROCEDURE
3 SET gradients TO []
4 FOR i FROM 0 TO LENGTH(tempReadings) DO
5 SET diff TO tempReadings[i + 1] - tempReadings[i]
6 APPEND diff TO gradients
7 END FOR
8 END PROCEDURE
The algorithm compiles successfully, but crashes due to an error on line 5 when it is executed.
Name this type of error.
159 exam-style questions on Edexcel GCSE Computer Science Algorithms, covering Constructs for solving problems, Variables, constants and data structures, Arithmetic, relational and logical operators, Tracing algorithm output with trace tables, Types of error and correcting logic errors, Standard algorithms (sorts and searches), and Evaluating algorithm fitness and efficiency. Each one has a worked solution and a mark scheme showing where the marks go.