Display apparatus, system, and screen generation method for displaying binary digital log data to facilitate anomaly detection

A display apparatus that displays log data which indicates when the log data deviates from a normal state and a deviation degree is provided. The display apparatus comprises: a memory to store prediction data including a signal value of a prediction value of the log data and accuracy degree of the prediction value, and a signal value of an actual measurement value of the log data; a control unit to generate a display screen on which a prediction value area indicating an area of the log data in normal state is depicted based on the prediction data and on which a signal wavelength of the signal value of the actual measurement value is depicted based on the signal value of the actual measurement value; and a display unit to display the display screen.